Release notesยค
v0.129ยค
Fixยค
- Fix error when template cache setting (
template_cache_size
) is set to 0.
v0.128ยค
Featยค
-
Configurable cache - Set
COMPONENTS.cache
to change where and how django-components caches JS and CSS files. (#946)Read more on Caching.
-
Highlight coponents and slots in the UI - We've added two boolean settings
COMPONENTS.debug_highlight_components
andCOMPONENTS.debug_highlight_slots
, which can be independently set toTrue
. First will wrap components in a blue border, the second will wrap slots in a red border. (#942)Read more on Troubleshooting.
Refactorยค
- Removed use of eval for node validation (#944)
Perfยค
-
Components can now be infinitely nested. (#936)
-
Component input validation is now 6-7x faster on CPython and PyPy. This previously made up 10-30% of the total render time. (#945)
v0.127ยค
Fixยค
- Fix component rendering when using
{% cache %}
with remote cache and multiple web servers (#930)
v0.126ยค
Refactorยค
- Replaced BeautifulSoup4 with a custom HTML parser.
- The heuristic for inserting JS and CSS dependenies into the default place has changed.
- JS is still inserted at the end of the
<body>
, and CSS at the end of<head>
. - However, we find end of
<body>
by searching for last occurrence of</body>
- And for the end of
<head>
we search for the first occurrence of</head>
- JS is still inserted at the end of the
v0.125ยค
โ ๏ธ Attention โ ๏ธ - We migrated from EmilStenstrom/django-components
to django-components/django-components
.
Repo name and documentation URL changed. Package name remains the same.
If you see any broken links or other issues, please report them in #922.
Featยค
@template_tag
andBaseNode
- A decorator and a class that allow you to define custom template tags that will behave similarly to django-components' own template tags.
Read more on Template tags.
Template tags defined with @template_tag
and BaseNode
will have the following features:
-
Accepting args, kwargs, and flags.
-
Allowing literal lists and dicts as inputs as:
key=[1, 2, 3]
orkey={"a": 1, "b": 2}
- Using template tags tag inputs as:{% my_tag key="{% lorem 3 w %}" / %}
- Supporting the flat dictionary definition:attr:key=value
- Spreading args and kwargs with...
:{% my_tag ...args ...kwargs / %}
- Being able to call the template tag as:{% my_tag %} ... {% endmy_tag %}
or{% my_tag / %}
Refactorยค
-
Refactored template tag input validation. When you now call template tags like
{% slot %}
,{% fill %}
,{% html_attrs %}
, and others, their inputs are now validated the same way as Python function inputs are.So, for example
{% slot "my_slot" name="content" / %} +
Release notes - Django-Components Django-ComponentsRelease notesRelease notesยค
v0.129ยค
Fixยค
- Fix thread unsafe media resolve validation by moving it to ComponentMedia
__post_init
(#977 - Fix bug: Relative path in extends and include does not work when using template_file (#976
- Fix error when template cache setting (
template_cache_size
) is set to 0 (#974
v0.128ยค
Featยค
-
Configurable cache - Set
COMPONENTS.cache
to change where and how django-components caches JS and CSS files. (#946)Read more on Caching.
-
Highlight coponents and slots in the UI - We've added two boolean settings
COMPONENTS.debug_highlight_components
andCOMPONENTS.debug_highlight_slots
, which can be independently set toTrue
. First will wrap components in a blue border, the second will wrap slots in a red border. (#942)Read more on Troubleshooting.
Refactorยค
- Removed use of eval for node validation (#944)
Perfยค
-
Components can now be infinitely nested. (#936)
-
Component input validation is now 6-7x faster on CPython and PyPy. This previously made up 10-30% of the total render time. (#945)
v0.127ยค
Fixยค
- Fix component rendering when using
{% cache %}
with remote cache and multiple web servers (#930)
v0.126ยค
Refactorยค
- Replaced BeautifulSoup4 with a custom HTML parser.
- The heuristic for inserting JS and CSS dependenies into the default place has changed.
- JS is still inserted at the end of the
<body>
, and CSS at the end of<head>
. - However, we find end of
<body>
by searching for last occurrence of</body>
- And for the end of
<head>
we search for the first occurrence of</head>
- JS is still inserted at the end of the
v0.125ยค
โ ๏ธ Attention โ ๏ธ - We migrated from
EmilStenstrom/django-components
todjango-components/django-components
.Repo name and documentation URL changed. Package name remains the same.
If you see any broken links or other issues, please report them in #922.
Featยค
@template_tag
andBaseNode
- A decorator and a class that allow you to define custom template tags that will behave similarly to django-components' own template tags.
Read more on Template tags.
Template tags defined with
@template_tag
andBaseNode
will have the following features:-
Accepting args, kwargs, and flags.
-
Allowing literal lists and dicts as inputs as:
key=[1, 2, 3]
orkey={"a": 1, "b": 2}
- Using template tags tag inputs as:{% my_tag key="{% lorem 3 w %}" / %}
- Supporting the flat dictionary definition:attr:key=value
- Spreading args and kwargs with...
:{% my_tag ...args ...kwargs / %}
- Being able to call the template tag as:{% my_tag %} ... {% endmy_tag %}
or{% my_tag / %}
Refactorยค
-
Refactored template tag input validation. When you now call template tags like
{% slot %}
,{% fill %}
,{% html_attrs %}
, and others, their inputs are now validated the same way as Python function inputs are.So, for example
will raise an error, because the positional argument
name
is given twice.NOTE: Special kwargs whose keys are not valid Python variable names are not affected by this change. So when you define:
The
data-id
will still be accepted as a valid kwarg, assuming that yourget_context_data()
accepts**kwargs
:def get_context_data(self, **kwargs): return { diff --git a/dev/search/search_index.json b/dev/search/search_index.json index d0fbdf27..63566125 100644 --- a/dev/search/search_index.json +++ b/dev/search/search_index.json @@ -1 +1 @@ -{"config":{"lang":["en"],"separator":"[\\s\\-]+","pipeline":["stopWordFilter"]},"docs":[{"location":"","title":"Welcome to Django Components","text":"
django-components
combines Django's templating system with the modularity seen in modern frontend frameworks like Vue or React.With
"},{"location":"#quickstart","title":"Quickstart","text":"django-components
you can support Django projects small and large without leaving the Django ecosystem.A component in django-components can be as simple as a Django template and Python code to declare the component:
components/calendar/calendar.html
components/calendar/calendar.py<div class=\"calendar\">\n Today's date is <span>{{ date }}</span>\n</div>\n
from django_components import Component\n\nclass Calendar(Component):\n template_file = \"calendar.html\"\n
Or a combination of Django template, Python, CSS, and Javascript:
components/calendar/calendar.html
components/calendar/calendar.css<div class=\"calendar\">\n Today's date is <span>{{ date }}</span>\n</div>\n
components/calendar/calendar.js.calendar {\n width: 200px;\n background: pink;\n}\n
components/calendar/calendar.pydocument.querySelector(\".calendar\").onclick = function () {\n alert(\"Clicked calendar!\");\n};\n
from django_components import Component\n\nclass Calendar(Component):\n template_file = \"calendar.html\"\n js_file = \"calendar.js\"\n css_file = \"calendar.css\"\n\n def get_context_data(self, date):\n return {\"date\": date}\n
Use the component like this:
{% component \"calendar\" date=\"2024-11-06\" %}{% endcomponent %}\n
And this is what gets rendered:
<div class=\"calendar-component\">\n Today's date is <span>2024-11-06</span>\n</div>\n
Read on to learn about all the exciting details and configuration possibilities!
(If you instead prefer to jump right into the code, check out the example project)
"},{"location":"#features","title":"Features","text":""},{"location":"#modern-and-modular-ui","title":"Modern and modular UI","text":"- Create self-contained, reusable UI elements.
- Each component can include its own HTML, CSS, and JS, or additional third-party JS and CSS.
- HTML, CSS, and JS can be defined on the component class, or loaded from files.
"},{"location":"#composition-with-slots","title":"Composition with slots","text":"from django_components import Component\n\n@register(\"calendar\")\nclass Calendar(Component):\n template = \"\"\"\n <div class=\"calendar\">\n Today's date is\n <span>{{ date }}</span>\n </div>\n \"\"\"\n\n css = \"\"\"\n .calendar {\n width: 200px;\n background: pink;\n }\n \"\"\"\n\n js = \"\"\"\n document.querySelector(\".calendar\")\n .addEventListener(\"click\", () => {\n alert(\"Clicked calendar!\");\n });\n \"\"\"\n\n # Additional JS and CSS\n class Media:\n js = [\"https://cdn.jsdelivr.net/npm/htmx.org@2.1.1/dist/htmx.min.js\"]\n css = [\"bootstrap/dist/css/bootstrap.min.css\"]\n\n # Variables available in the template\n def get_context_data(self, date):\n return {\n \"date\": date\n }\n
- Render components inside templates with
{% component %}
tag. - Compose them with
{% slot %}
and{% fill %}
tags. - Vue-like slot system, including scoped slots.
"},{"location":"#extended-template-tags","title":"Extended template tags","text":"{% component \"Layout\"\n bookmarks=bookmarks\n breadcrumbs=breadcrumbs\n%}\n {% fill \"header\" %}\n <div class=\"flex justify-between gap-x-12\">\n <div class=\"prose\">\n <h3>{{ project.name }}</h3>\n </div>\n <div class=\"font-semibold text-gray-500\">\n {{ project.start_date }} - {{ project.end_date }}\n </div>\n </div>\n {% endfill %}\n\n {# Access data passed to `{% slot %}` with `data` #}\n {% fill \"tabs\" data=\"tabs_data\" %}\n {% component \"TabItem\" header=\"Project Info\" %}\n {% component \"ProjectInfo\"\n project=project\n project_tags=project_tags\n attrs:class=\"py-5\"\n attrs:width=tabs_data.width\n / %}\n {% endcomponent %}\n {% endfill %}\n{% endcomponent %}\n
django-components
extends Django's template tags syntax with:- Literal lists and dictionaries in template tags
- Self-closing tags
{% mytag / %}
- Multi-line template tags
- Spread operator
...
to dynamically pass args or kwargs into the template tag - Nested template tags like
\"{{ first_name }} {{ last_name }}\"
- Flat definition of dictionary keys
attr:key=val
"},{"location":"#html-fragment-support","title":"HTML fragment support","text":"{% component \"table\"\n ...default_attrs\n title=\"Friend list for {{ user.name }}\"\n headers=[\"Name\", \"Age\", \"Email\"]\n data=[\n {\n \"name\": \"John\"|upper,\n \"age\": 30|add:1,\n \"email\": \"john@example.com\",\n \"hobbies\": [\"reading\"],\n },\n {\n \"name\": \"Jane\"|upper,\n \"age\": 25|add:1,\n \"email\": \"jane@example.com\",\n \"hobbies\": [\"reading\", \"coding\"],\n },\n ],\n attrs:class=\"py-4 ma-2 border-2 border-gray-300 rounded-md\"\n/ %}\n
django-components
makes intergration with HTMX, AlpineJS or jQuery easy by allowing components to be rendered as HTML fragments:-
Components's JS and CSS is loaded automatically when the fragment is inserted into the DOM
-
Expose components as views with
get
,post
,put
,patch
,delete
methods
"},{"location":"#type-hints","title":"Type hints","text":"# components/calendar/calendar.py\n@register(\"calendar\")\nclass Calendar(Component):\n template_file = \"calendar.html\"\n\n def get(self, request, *args, **kwargs):\n page = request.GET.get(\"page\", 1)\n return self.render_to_response(\n kwargs={\n \"page\": page,\n }\n )\n\n def get_context_data(self, page):\n return {\n \"page\": page,\n }\n\n# urls.py\npath(\"calendar/\", Calendar.as_view()),\n
Opt-in to type hints by defining types for component's args, kwargs, slots, and more:
from typing import NotRequired, Tuple, TypedDict, SlotContent, SlotFunc\n\nButtonArgs = Tuple[int, str]\n\nclass ButtonKwargs(TypedDict):\n variable: str\n another: int\n maybe_var: NotRequired[int] # May be omitted\n\nclass ButtonData(TypedDict):\n variable: str\n\nclass ButtonSlots(TypedDict):\n my_slot: NotRequired[SlotFunc]\n another_slot: SlotContent\n\nButtonType = Component[ButtonArgs, ButtonKwargs, ButtonSlots, ButtonData, JsData, CssData]\n\nclass Button(ButtonType):\n def get_context_data(self, *args, **kwargs):\n self.input.args[0] # int\n self.input.kwargs[\"variable\"] # str\n self.input.slots[\"my_slot\"] # SlotFunc[MySlotData]\n\n return {} # Error: Key \"variable\" is missing\n
When you then call
Button.render()
orButton.render_to_response()
, you will get type hints:
"},{"location":"#debugging-features","title":"Debugging features","text":"Button.render(\n # Error: First arg must be `int`, got `float`\n args=(1.25, \"abc\"),\n # Error: Key \"another\" is missing\n kwargs={\n \"variable\": \"text\",\n },\n)\n
- Visual component inspection: Highlight components and slots directly in your browser.
- Detailed tracing logs to supply AI-agents with context: The logs include component and slot names and IDs, and their position in the tree.
- Install and use third-party components from PyPI
- Or publish your own \"component registry\"
-
Highly customizable - Choose how the components are called in the template (and more):
{% component \"calendar\" date=\"2024-11-06\" %}\n{% endcomponent %}\n\n{% calendar date=\"2024-11-06\" %}\n{% endcalendar %}\n
- Vue-like provide / inject system
- Format HTML attributes with
{% html_attrs %}
Read the Release Notes to see the latest features and fixes.
"},{"location":"#community-examples","title":"Community examples","text":"One of our goals with
"},{"location":"#contributing-and-development","title":"Contributing and development","text":"django-components
is to make it easy to share components between projects. Head over to the Community examples to see some examples.Get involved or sponsor this project - See here
Running django-components locally for development - See here
"},{"location":"SUMMARY/","title":"SUMMARY","text":"- Overview
- Getting Started
- Concepts
- Fundamentals
- Advanced
- Guides
- Setup
- Other
- Dev guides
- API Documentation
- Release notes
This guide is for you if you're upgrating django_components to v0.100 or later from older versions.
In version 0.100, we changed how components' static JS and CSS files are handled. See more in the \"Static files\" section.
Migration steps:
- Remove
django_components.safer_staticfiles
fromINSTALLED_APPS
in yoursettings.py
, and replace it withdjango.contrib.staticfiles
.
Before:
INSTALLED_APPS = [\n \"django.contrib.admin\",\n ...\n # \"django.contrib.staticfiles\", # <-- ADD\n \"django_components\",\n \"django_components.safer_staticfiles\", # <-- REMOVE\n]\n
After:
INSTALLED_APPS = [\n \"django.contrib.admin\",\n ...\n \"django.contrib.staticfiles\",\n \"django_components\",\n]\n
- Add
STATICFILES_FINDERS
tosettings.py
, and adddjango_components.finders.ComponentsFileSystemFinder
:
STATICFILES_FINDERS = [\n # Default finders\n \"django.contrib.staticfiles.finders.FileSystemFinder\",\n \"django.contrib.staticfiles.finders.AppDirectoriesFinder\",\n # Django components\n \"django_components.finders.ComponentsFileSystemFinder\", # <-- ADDED\n]\n
- Add
COMPONENTS.dirs
tosettings.py
.
If you previously defined
STATICFILES_DIRS
, move only those directories fromSTATICFILES_DIRS
that point to components directories, and keep the rest.E.g. if you have
STATICFILES_DIRS
like this:STATICFILES_DIRS = [\n BASE_DIR / \"components\", # <-- MOVE\n BASE_DIR / \"myapp\" / \"components\", # <-- MOVE\n BASE_DIR / \"assets\",\n]\n
Then first two entries point to components dirs, whereas
/assets
points to non-component static files. In this case move only the first two paths:COMPONENTS = {\n \"dirs\": [\n BASE_DIR / \"components\", # <-- MOVED\n BASE_DIR / \"myapp\" / \"components\", # <-- MOVED\n ],\n}\n\nSTATICFILES_DIRS = [\n BASE_DIR / \"assets\",\n]\n
Moreover, if you defined app-level component directories in
STATICFILES_DIRS
before, you can now define as a RELATIVE path inapp_dirs
:
"},{"location":"release_notes/","title":"Release notes","text":""},{"location":"release_notes/#v0129","title":"v0.129","text":""},{"location":"release_notes/#fix","title":"Fix","text":"COMPONENTS = {\n \"dirs\": [\n # Search top-level \"/components/\" dir\n BASE_DIR / \"components\",\n ],\n \"app_dirs\": [\n # Search \"/[app]/components/\" dirs\n \"components\",\n ],\n}\n\nSTATICFILES_DIRS = [\n BASE_DIR / \"assets\",\n]\n
- Fix error when template cache setting (
template_cache_size
) is set to 0.
-
Configurable cache - Set
COMPONENTS.cache
to change where and how django-components caches JS and CSS files. (#946)Read more on Caching.
-
Highlight coponents and slots in the UI - We've added two boolean settings
COMPONENTS.debug_highlight_components
andCOMPONENTS.debug_highlight_slots
, which can be independently set toTrue
. First will wrap components in a blue border, the second will wrap slots in a red border. (#942)Read more on Troubleshooting.
- Removed use of eval for node validation (#944)
-
Components can now be infinitely nested. (#936)
-
Component input validation is now 6-7x faster on CPython and PyPy. This previously made up 10-30% of the total render time. (#945)
- Fix component rendering when using
{% cache %}
with remote cache and multiple web servers (#930)
- Replaced BeautifulSoup4 with a custom HTML parser.
- The heuristic for inserting JS and CSS dependenies into the default place has changed.
- JS is still inserted at the end of the
<body>
, and CSS at the end of<head>
. - However, we find end of
<body>
by searching for last occurrence of</body>
- And for the end of
<head>
we search for the first occurrence of</head>
- JS is still inserted at the end of the
\u26a0\ufe0f Attention \u26a0\ufe0f - We migrated from
EmilStenstrom/django-components
todjango-components/django-components
.Repo name and documentation URL changed. Package name remains the same.
If you see any broken links or other issues, please report them in #922.
"},{"location":"release_notes/#feat_1","title":"Feat","text":"@template_tag
andBaseNode
- A decorator and a class that allow you to define custom template tags that will behave similarly to django-components' own template tags.
Read more on Template tags.
Template tags defined with
@template_tag
andBaseNode
will have the following features:-
Accepting args, kwargs, and flags.
-
Allowing literal lists and dicts as inputs as:
key=[1, 2, 3]
orkey={\"a\": 1, \"b\": 2}
- Using template tags tag inputs as:{% my_tag key=\"{% lorem 3 w %}\" / %}
- Supporting the flat dictionary definition:attr:key=value
- Spreading args and kwargs with...
:{% my_tag ...args ...kwargs / %}
- Being able to call the template tag as:{% my_tag %} ... {% endmy_tag %}
or{% my_tag / %}
-
Refactored template tag input validation. When you now call template tags like
{% slot %}
,{% fill %}
,{% html_attrs %}
, and others, their inputs are now validated the same way as Python function inputs are.So, for example
{% slot \"my_slot\" name=\"content\" / %}\n
will raise an error, because the positional argument
name
is given twice.NOTE: Special kwargs whose keys are not valid Python variable names are not affected by this change. So when you define:
{% component data-id=123 / %}\n
The
data-id
will still be accepted as a valid kwarg, assuming that yourget_context_data()
accepts**kwargs
:def get_context_data(self, **kwargs):\n return {\n \"data_id\": kwargs[\"data-id\"],\n }\n
-
Instead of inlining the JS and CSS under
Component.js
andComponent.css
, you can move them to their own files, and link the JS/CSS files withComponent.js_file
andComponent.css_file
.Even when you specify the JS/CSS with
Component.js_file
orComponent.css_file
, then you can still access the content underComponent.js
orComponent.css
- behind the scenes, the content of the JS/CSS files will be set toComponent.js
/Component.css
upon first access.The same applies to
Component.template_file
, which will populateComponent.template
upon first access.With this change, the role of
Component.js/css
and the JS/CSS inComponent.Media
has changed:- The JS/CSS defined in
Component.js/css
orComponent.js/css_file
is the \"main\" JS/CSS - The JS/CSS defined in
Component.Media.js/css
are secondary or additional
See the updated \"Getting Started\" tutorial
- The JS/CSS defined in
-
The canonical way to define a template file was changed from
template_name
totemplate_file
, to align with the rest of the API.template_name
remains for backwards compatibility. When you get / settemplate_name
, internally this is proxied totemplate_file
. -
The undocumented
Component.component_id
was removed. Instead, useComponent.id
. Changes:- While
component_id
was unique every time you instantiatedComponent
, the newid
is unique every time you render the component (e.g. withComponent.render()
) - The new
id
is available only during render, so e.g. from withinget_context_data()
- While
-
Component's HTML / CSS / JS are now resolved and loaded lazily. That is, if you specify
template_name
/template_file
,js_file
,css_file
, orMedia.js/css
, the file paths will be resolved only once you:- Try to access component's HTML / CSS / JS, or
- Render the component.
Read more on Accessing component's HTML / JS / CSS.
-
Component inheritance:
- When you subclass a component, the JS and CSS defined on parent's
Media
class is now inherited by the child component. - You can disable or customize Media inheritance by setting
extend
attribute on theComponent.Media
nested class. This work similarly to Django'sMedia.extend
. - When child component defines either
template
ortemplate_file
, both of parent'stemplate
andtemplate_file
are ignored. The same applies tojs_file
andcss_file
.
- When you subclass a component, the JS and CSS defined on parent's
-
Autodiscovery now ignores files and directories that start with an underscore (
_
), except__init__.py
-
The Signals emitted by or during the use of django-components are now documented, together the
template_rendered
signal.
- Fix edge cases around rendering components whose templates used the
{% extends %}
template tag (#859)
- Add support for HTML fragments. HTML fragments can be rendered by passing
type=\"fragment\"
toComponent.render()
orComponent.render_to_response()
. Read more on how to use HTML fragments with HTMX, AlpineJS, or vanillaJS.
- Fix the use of Django template filters (
|lower:\"etc\"
) with component inputs #855.
\u26a0\ufe0f Attention \u26a0\ufe0f - Please update to v0.121 to fix bugs introduced in v0.119.
"},{"location":"release_notes/#fix_4","title":"Fix","text":"- Fix the use of translation strings
_(\"bla\")
as inputs to components #849.
\u26a0\ufe0f Attention \u26a0\ufe0f - This release introduced bugs #849, #855. Please update to v0.121.
"},{"location":"release_notes/#fix_5","title":"Fix","text":"- Fix compatibility with custom subclasses of Django's
Template
that need to accessorigin
or other initialization arguments. (https://github.com/django-components/django-components/pull/828)
- Compatibility with
django-debug-toolbar-template-profiler
: -
Monkeypatching of Django's
Template
now happens atAppConfig.ready()
(https://github.com/django-components/django-components/pull/825) -
Internal parsing of template tags tag was updated. No API change. (https://github.com/django-components/django-components/pull/827)
- Add support for
context_processors
andRenderContext
inside component templates
Component.render()
andComponent.render_to_response()
now accept an extra kwargrequest
.```py\ndef my_view(request)\n return MyTable.render_to_response(\n request=request\n )\n```\n
-
When you pass in
request
, the component will useRenderContext
instead ofContext
. Thus the context processors will be applied to the context. -
NOTE: When you pass in both
request
andcontext
toComponent.render()
, andcontext
is already an instance ofContext
, therequest
kwarg will be ignored.
- The HTML parser no longer erronously inserts
<html><head><body>
on some occasions, and no longer tries to close unclosed HTML tags.
- Replaced Selectolax with BeautifulSoup4 as project dependencies.
\u26a0\ufe0f Attention \u26a0\ufe0f - Please update to v0.117 to fix known bugs. See #791 and #789 and #818.
"},{"location":"release_notes/#fix_7","title":"Fix","text":"- Fix the order of execution of JS scripts:
- Scripts in
Component.Media.js
are executed in the order they are defined -
Scripts in
Component.js
are executed AFTERMedia.js
scripts -
Fix compatibility with AlpineJS
- Scripts in
Component.Media.js
are now again inserted as<script>
tags - By default,
Component.Media.js
are inserted as synchronous<script>
tags, so the AlpineJS components registered in theMedia.js
scripts will now again run BEFORE the core AlpineJS script.
AlpineJS can be configured like so:
Option 1 - AlpineJS loaded in
<head>
withdefer
attribute:<html>\n <head>\n {% component_css_dependencies %}\n <script defer src=\"https://unpkg.com/alpinejs\"></script>\n </head>\n <body>\n {% component 'my_alpine_component' / %}\n {% component_js_dependencies %}\n </body>\n</html>\n
Option 2 - AlpineJS loaded in
<body>
AFTER{% component_js_depenencies %}
:
"},{"location":"release_notes/#v0115","title":"v0.115","text":"<html>\n <head>\n {% component_css_dependencies %}\n </head>\n <body>\n {% component 'my_alpine_component' / %}\n {% component_js_dependencies %}\n\n <script src=\"https://unpkg.com/alpinejs\"></script>\n </body>\n</html>\n
\u26a0\ufe0f Attention \u26a0\ufe0f - Please update to v0.117 to fix known bugs. See #791 and #789 and #818.
"},{"location":"release_notes/#fix_8","title":"Fix","text":"- Fix integration with ManifestStaticFilesStorage on Windows by resolving component filepaths (like
Component.template_name
) to POSIX paths.
\u26a0\ufe0f Attention \u26a0\ufe0f - Please update to v0.117 to fix known bugs. See #791 and #789 and #818.
"},{"location":"release_notes/#fix_9","title":"Fix","text":"- Prevent rendering Slot tags during fill discovery stage to fix a case when a component inside a slot fill tried to access provided data too early.
\u26a0\ufe0f Attention \u26a0\ufe0f - Please update to v0.117 to fix known bugs. See #791 and #789 and #818.
"},{"location":"release_notes/#fix_10","title":"Fix","text":"- Ensure consistent order of scripts in
Component.Media.js
\u26a0\ufe0f Attention \u26a0\ufe0f - Please update to v0.117 to fix known bugs. See #791 and #789 and #818.
"},{"location":"release_notes/#fix_11","title":"Fix","text":"- Allow components to accept default fill even if no default slot was encountered during rendering
\u26a0\ufe0f Attention \u26a0\ufe0f - Please update to v0.117 to fix known bugs. See #791 and #789 and #818.
"},{"location":"release_notes/#fix_12","title":"Fix","text":"- Prevent rendering Component tags during fill discovery stage to fix a case when a component inside the default slot tried to access provided data too early.
\u26a0\ufe0f Attention \u26a0\ufe0f - Please update to v0.117 to fix known bugs. See #791 and #789 and #818.
"},{"location":"release_notes/#general","title":"General","text":""},{"location":"release_notes/#breaking-changes","title":"\ud83d\udea8\ud83d\udce2 BREAKING CHANGES","text":"-
Installation changes:
- If your components include JS or CSS, you now must use the middleware and add django-components' URLs to your
urlpatterns
(See \"Adding support for JS and CSS\")
- If your components include JS or CSS, you now must use the middleware and add django-components' URLs to your
-
Component typing signature changed from
Component[Args, Kwargs, Data, Slots]\n
to
Component[Args, Kwargs, Slots, Data, JsData, CssData]\n
-
If you rendered a component A with
Component.render()
and then inserted that into another component B, now you must passrender_dependencies=False
to component A:prerendered_a = CompA.render(\n args=[...],\n kwargs={...},\n render_dependencies=False,\n)\n\nhtml = CompB.render(\n kwargs={\n content=prerendered_a,\n },\n)\n
- Intellisense and mypy validation for settings:
Instead of defining the
COMPONENTS
settings as a plain dict, you can useComponentsSettings
:# settings.py\nfrom django_components import ComponentsSettings\n\nCOMPONENTS = ComponentsSettings(\n autodiscover=True,\n ...\n)\n
- Use
get_component_dirs()
andget_component_files()
to get the same list of dirs / files that would be imported byautodiscover()
, but without actually importing them.
-
For advanced use cases, use can omit the middleware and instead manage component JS and CSS dependencies yourself with
render_dependencies
-
The
ComponentRegistry
settingsRegistrySettings
were lowercased to align with the global settings: RegistrySettings.CONTEXT_BEHAVIOR
->RegistrySettings.context_behavior
RegistrySettings.TAG_FORMATTER
->RegistrySettings.tag_formatter
The old uppercase settings
CONTEXT_BEHAVIOR
andTAG_FORMATTER
are deprecated and will be removed in v1.-
The setting
reload_on_template_change
was renamed toreload_on_file_change
. And now it properly triggers server reload when any file in the component dirs change. The old namereload_on_template_change
is deprecated and will be removed in v1. -
The setting
forbidden_static_files
was renamed tostatic_files_forbidden
to align withstatic_files_allowed
The old nameforbidden_static_files
is deprecated and will be removed in v1.
-
{% component_dependencies %}
tag was removed. Instead, use{% component_js_dependencies %}
and{% component_css_dependencies %}
-
The combined tag was removed to encourage the best practice of putting JS scripts at the end of
<body>
, and CSS styles inside<head>
.On the other hand, co-locating JS script and CSS styles can lead to a flash of unstyled content, as either JS scripts will block the rendering, or CSS will load too late.
-
-
The undocumented keyword arg
preload
of{% component_js_dependencies %}
and{% component_css_dependencies %}
tags was removed. This will be replaced with HTML fragment support.
- Allow using forward slash (
/
) when defining custom TagFormatter, e.g.{% MyComp %}..{% /MyComp %}
.
{% component_dependencies %}
tags are now OPTIONAL - If your components use JS and CSS, but you don't use{% component_dependencies %}
tags, the JS and CSS will now be, by default, inserted at the end of<body>
and at the end of<head>
respectively.
- Fills can now be defined within loops (
{% for %}
) or other tags (like{% with %}
), or even other templates using{% include %}
.
Following is now possible
{% component \"table\" %}\n {% for slot_name in slots %}\n {% fill name=slot_name %}\n {% endfill %}\n {% endfor %}\n{% endcomponent %}\n
- If you need to access the data or the default content of a default fill, you can set the
name
kwarg to\"default\"
.
Previously, a default fill would be defined simply by omitting the
{% fill %}
tags:{% component \"child\" %}\n Hello world\n{% endcomponent %}\n
But in that case you could not access the slot data or the default content, like it's possible for named fills:
{% component \"child\" %}\n {% fill name=\"header\" data=\"data\" %}\n Hello {{ data.user.name }}\n {% endfill %}\n{% endcomponent %}\n
Now, you can specify default tag by using
name=\"default\"
:{% component \"child\" %}\n {% fill name=\"default\" data=\"data\" %}\n Hello {{ data.user.name }}\n {% endfill %}\n{% endcomponent %}\n
- When inside
get_context_data()
or other component methods, the default fill can now be accessed asComponent.input.slots[\"default\"]
, e.g.:
class MyTable(Component):\n def get_context_data(self, *args, **kwargs):\n default_slot = self.input.slots[\"default\"]\n ...\n
- You can now dynamically pass all slots to a child component. This is similar to passing all slots in Vue:
"},{"location":"release_notes/#fix_14","title":"Fix","text":"class MyTable(Component):\n def get_context_data(self, *args, **kwargs):\n return {\n \"slots\": self.input.slots,\n }\n\n template: \"\"\"\n <div>\n {% component \"child\" %}\n {% for slot_name in slots %}\n {% fill name=slot_name data=\"data\" %}\n {% slot name=slot_name ...data / %}\n {% endfill %}\n {% endfor %}\n {% endcomponent %}\n </div>\n \"\"\"\n
-
Slots defined with
{% fill %}
tags are now properly accessible viaself.input.slots
inget_context_data()
-
Do not raise error if multiple slots with same name are flagged as default
-
Slots can now be defined within loops (
{% for %}
) or other tags (like{% with %}
), or even other templates using{% include %}
.
Previously, following would cause the kwarg
name
to be an empty string:
"},{"location":"release_notes/#refactor_8","title":"Refactor","text":"{% for slot_name in slots %}\n {% slot name=slot_name %}\n{% endfor %}\n
- When you define multiple slots with the same name inside a template, you now have to set the
default
andrequired
flags individually.
<div class=\"calendar-component\">\n <div class=\"header\">\n {% slot \"image\" default required %}Image here{% endslot %}\n </div>\n <div class=\"body\">\n {% slot \"image\" default required %}Image here{% endslot %}\n </div>\n</div>\n
This means you can also have multiple slots with the same name but different conditions.
E.g. in this example, we have a component that renders a user avatar - a small circular image with a profile picture of name initials.
If the component is given
image_src
orname_initials
variables, theimage
slot is optional. But if neither of those are provided, you MUST fill theimage
slot.<div class=\"avatar\">\n {% if image_src %}\n {% slot \"image\" default %}\n <img src=\"{{ image_src }}\" />\n {% endslot %}\n {% elif name_initials %}\n {% slot \"image\" default required %}\n <div style=\"\n border-radius: 25px;\n width: 50px;\n height: 50px;\n background: blue;\n \">\n {{ name_initials }}\n </div>\n {% endslot %}\n {% else %}\n {% slot \"image\" default required / %}\n {% endif %}\n</div>\n
- The slot fills that were passed to a component and which can be accessed as
Component.input.slots
can now be passed through the Django template, e.g. as inputs to other tags.
Internally, django-components handles slot fills as functions.
Previously, if you tried to pass a slot fill within a template, Django would try to call it as a function.
Now, something like this is possible:
class MyTable(Component):\n def get_context_data(self, *args, **kwargs):\n return {\n \"child_slot\": self.input.slots[\"child_slot\"],\n }\n\n template: \"\"\"\n <div>\n {% component \"child\" content=child_slot / %}\n </div>\n \"\"\"\n
NOTE: Using
{% slot %}
and{% fill %}
tags is still the preferred method, but the approach above may be necessary in some complex or edge cases.- The
is_filled
variable (and the{{ component_vars.is_filled }}
context variable) now returnsFalse
when you try to access a slot name which has not been defined:
Before:
{{ component_vars.is_filled.header }} -> True\n{{ component_vars.is_filled.footer }} -> False\n{{ component_vars.is_filled.nonexist }} -> \"\" (empty string)\n
After:
{{ component_vars.is_filled.header }} -> True\n{{ component_vars.is_filled.footer }} -> False\n{{ component_vars.is_filled.nonexist }} -> False\n
-
Components no longer raise an error if there are extra slot fills
-
Components will raise error when a slot is doubly-filled.
E.g. if we have a component with a default slot:
{% slot name=\"content\" default / %}\n
Now there is two ways how we can target this slot: Either using
name=\"default\"
orname=\"content\"
.In case you specify BOTH, the component will raise an error:
"},{"location":"release_notes/#v0100","title":"\ud83d\udea8\ud83d\udce2 v0.100","text":""},{"location":"release_notes/#breaking-changes_2","title":"BREAKING CHANGES","text":"{% component \"child\" %}\n {% fill slot=\"default\" %}\n Hello from default slot\n {% endfill %}\n {% fill slot=\"content\" data=\"data\" %}\n Hello from content slot\n {% endfill %}\n{% endcomponent %}\n
-
django_components.safer_staticfiles
app was removed. It is no longer needed. -
Installation changes:
- Instead of defining component directories in
STATICFILES_DIRS
, set them toCOMPONENTS.dirs
. -
You now must define
STATICFILES_FINDERS
-
See here how to migrate your settings.py
- Instead of defining component directories in
- Beside the top-level
/components
directory, you can now define also app-level components dirs, e.g.[app]/components
(SeeCOMPONENTS.app_dirs
).
- When you call
as_view()
on a component instance, that instance will be passed toView.as_view()
- Fixed template caching. You can now also manually create cached templates with
cached_template()
-
The previously undocumented
get_template
was made private. -
In it's place, there's a new
get_template
, which supersedesget_template_string
(will be removed in v1). The newget_template
is the same asget_template_string
, except it allows to return either a string or a Template instance. -
You now must use only one of
template
,get_template
,template_name
, orget_template_name
.
-
Run-time type validation for Python 3.11+ - If the
Component
class is typed, e.g.Component[Args, Kwargs, ...]
, the args, kwargs, slots, and data are validated against the given types. (See Runtime input validation with types) -
Render hooks - Set
on_render_before
andon_render_after
methods onComponent
to intercept or modify the template or context before rendering, or the rendered result afterwards. (See Component hooks) -
component_vars.is_filled
context variable can be accessed from withinon_render_before
andon_render_after
hooks asself.is_filled.my_slot
- Added support for dynamic components, where the component name is passed as a variable. (See Dynamic components)
- Changed
Component.input
to raiseRuntimeError
if accessed outside of render context. Previously it returnedNone
if unset.
-
django_components now automatically configures Django to support multi-line tags. (See Multi-line tags)
-
New setting
reload_on_template_change
. Set this toTrue
to reload the dev server on changes to component template files. (See Reload dev server on component file changes)
-
Spread operator
...dict
inside template tags. (See Spread operator) -
Use template tags inside string literals in component inputs. (See Use template tags inside component inputs)
-
Dynamic slots, fills and provides - The
name
argument for these can now be a variable, a template expression, or via spread operator -
Component library authors can now configure
CONTEXT_BEHAVIOR
andTAG_FORMATTER
settings independently from user settings.
Component
class is no longer a subclass ofView
. To configure theView
class, set theComponent.View
nested class. HTTP methods likeget
orpost
can still be defined directly onComponent
class, andComponent.as_view()
internally callsComponent.View.as_view()
. (See Modifying the View class)
-
The inputs (args, kwargs, slots, context, ...) that you pass to
Component.render()
can be accessed from withinget_context_data
,get_template
andget_template_name
viaself.input
. (See Accessing data passed to the component) -
Typing:
Component
class supports generics that specify types forComponent.render
(See Adding type hints with Generics)
-
All tags (
component
,slot
,fill
, ...) now support \"self-closing\" or \"inline\" form, where you can omit the closing tag:{# Before #}\n{% component \"button\" %}{% endcomponent %}\n{# After #}\n{% component \"button\" / %}\n
-
All tags now support the \"dictionary key\" or \"aggregate\" syntax (
kwarg:key=val
):{% component \"button\" attrs:class=\"hidden\" %}\n
-
You can change how the components are written in the template with TagFormatter.
The default is
django_components.component_formatter
:{% component \"button\" href=\"...\" disabled %}\n Click me!\n{% endcomponent %}\n
While
django_components.shorthand_component_formatter
allows you to write components like so:{% button href=\"...\" disabled %}\n Click me!\n{% endbutton %}\n
-
Autodiscovery module resolution changed. Following undocumented behavior was removed:
-
Previously, autodiscovery also imported any
[app]/components.py
files, and usedSETTINGS_MODULE
to search for component dirs.To migrate from:
-
[app]/components.py
- Define each module inCOMPONENTS.libraries
setting, or import each module inside theAppConfig.ready()
hook in respectiveapps.py
files. -
SETTINGS_MODULE
- Define component dirs usingSTATICFILES_DIRS
-
-
Previously, autodiscovery handled relative files in
STATICFILES_DIRS
. To align with Django,STATICFILES_DIRS
now must be full paths (Django docs).
-
- The order of arguments to
render_to_response
has changed, to align with the (now public)render
method ofComponent
class.
-
Component.render()
is public and documented -
Slots passed
render_to_response
andrender
can now be rendered also as functions.
- Vue-like provide/inject with the
{% provide %}
tag andinject()
method.
- Default value for the
COMPONENTS.context_behavior
setting was changes from\"isolated\"
to\"django\"
. If you did not set this value explicitly before, this may be a breaking change. See the rationale for change here.
-
The syntax for accessing default slot content has changed from
{% fill \"my_slot\" as \"alias\" %}\n {{ alias.default }}\n{% endfill %}\n
to
{% fill \"my_slot\" default=\"alias\" %}\n {{ alias }}\n{% endfill %}\n
-
{% html_attrs %}
tag for formatting data as HTML attributes -
prefix:key=val
construct for passing dicts to components
-
{% if_filled \"my_slot\" %}
tags were replaced with{{ component_vars.is_filled.my_slot }}
variables. -
Simplified settings -
slot_context_behavior
andcontext_behavior
were merged. See the documentation for more details.
- Changed the default way how context variables are resolved in slots. See the documentation for more details.
-
{% component_block %}
is now{% component %}
, and{% component %}
blocks need an ending{% endcomponent %}
tag.The new
python manage.py upgradecomponent
command can be used to upgrade a directory (use--path
argument to point to each dir) of templates that use components to the new syntax automatically.This change is done to simplify the API in anticipation of a 1.0 release of django_components. After 1.0 we intend to be stricter with big changes like this in point releases.
- Components as views, which allows you to handle requests and render responses from within a component. See the documentation for more details.
- 'implicit' slot filling and the
default
option forslot
tags.
- A second installable app
django_components.safer_staticfiles
. It provides the same behavior asdjango.contrib.staticfiles
but with extra security guarantees (more info below in Security Notes).
-
Changed the syntax for
{% slot %}
tags. From now on, we separate defining a slot ({% slot %}
) from filling a slot with content ({% fill %}
). This means you will likely need to change a lot of slot tags to fill.We understand this is annoying, but it's the only way we can get support for nested slots that fill in other slots, which is a very nice feature to have access to. Hoping that this will feel worth it!
-
All files inside components subdirectores are autoimported to simplify setup.
An existing project might start to get
AlreadyRegistered
errors because of this. To solve this, either remove your custom loading of components, or set\"autodiscover\": False
insettings.COMPONENTS
.
-
Renamed
Component.context
andComponent.template
toget_context_data
andget_template_name
. The old methods still work, but emit a deprecation warning.This change was done to sync naming with Django's class based views, and make using django-components more familiar to Django users.
Component.context
andComponent.template
will be removed when version 1.0 is released.
You can publish and share your components for others to use. Below you will find the steps to do so.
For live examples, see the Community examples.
"},{"location":"concepts/advanced/authoring_component_libraries/#writing-component-libraries","title":"Writing component libraries","text":"-
Create a Django project with a similar structure:
project/\n |-- myapp/\n |-- __init__.py\n |-- apps.py\n |-- templates/\n |-- table/\n |-- table.py\n |-- table.js\n |-- table.css\n |-- table.html\n |-- menu.py <--- single-file component\n |-- templatetags/\n |-- __init__.py\n |-- mytags.py\n
-
Create custom
Library
andComponentRegistry
instances inmytags.py
This will be the entrypoint for using the components inside Django templates.
Remember that Django requires the
Library
instance to be accessible under theregister
variable (See Django docs):from django.template import Library\nfrom django_components import ComponentRegistry, RegistrySettings\n\nregister = library = django.template.Library()\ncomp_registry = ComponentRegistry(\n library=library,\n settings=RegistrySettings(\n context_behavior=\"isolated\",\n tag_formatter=\"django_components.component_formatter\",\n ),\n)\n
As you can see above, this is also the place where we configure how our components should behave, using the
settings
argument. If omitted, default settings are used.For library authors, we recommend setting
context_behavior
to\"isolated\"
, so that the state cannot leak into the components, and so the components' behavior is configured solely through the inputs. This means that the components will be more predictable and easier to debug.Next, you can decide how will others use your components by setting the
tag_formatter
options.If omitted or set to
\"django_components.component_formatter\"
, your components will be used like this:{% component \"table\" items=items headers=headers %}\n{% endcomponent %}\n
Or you can use
\"django_components.component_shorthand_formatter\"
to use components like so:{% table items=items headers=headers %}\n{% endtable %}\n
Or you can define a custom TagFormatter.
Either way, these settings will be scoped only to your components. So, in the user code, there may be components side-by-side that use different formatters:
{% load mytags %}\n\n{# Component from your library \"mytags\", using the \"shorthand\" formatter #}\n{% table items=items headers=header %}\n{% endtable %}\n\n{# User-created components using the default settings #}\n{% component \"my_comp\" title=\"Abc...\" %}\n{% endcomponent %}\n
-
Write your components and register them with your instance of
ComponentRegistry
There's one difference when you are writing components that are to be shared, and that's that the components must be explicitly registered with your instance of
ComponentRegistry
from the previous step.For better user experience, you can also define the types for the args, kwargs, slots and data.
It's also a good idea to have a common prefix for your components, so they can be easily distinguished from users' components. In the example below, we use the prefix
my_
/My
.from typing import Dict, NotRequired, Optional, Tuple, TypedDict\n\nfrom django_components import Component, SlotFunc, register, types\n\nfrom myapp.templatetags.mytags import comp_registry\n\n# Define the types\nclass EmptyDict(TypedDict):\n pass\n\ntype MyMenuArgs = Tuple[int, str]\n\nclass MyMenuSlots(TypedDict):\n default: NotRequired[Optional[SlotFunc[EmptyDict]]]\n\nclass MyMenuProps(TypedDict):\n vertical: NotRequired[bool]\n klass: NotRequired[str]\n style: NotRequired[str]\n\n# Define the component\n# NOTE: Don't forget to set the `registry`!\n@register(\"my_menu\", registry=comp_registry)\nclass MyMenu(Component[MyMenuArgs, MyMenuProps, MyMenuSlots, Any, Any, Any]):\n def get_context_data(\n self,\n *args,\n attrs: Optional[Dict] = None,\n ):\n return {\n \"attrs\": attrs,\n }\n\n template: types.django_html = \"\"\"\n {# Load django_components template tags #}\n {% load component_tags %}\n\n <div {% html_attrs attrs class=\"my-menu\" %}>\n <div class=\"my-menu__content\">\n {% slot \"default\" default / %}\n </div>\n </div>\n \"\"\"\n
-
Import the components in
apps.py
Normally, users rely on autodiscovery and
COMPONENTS.dirs
to load the component files.Since you, as the library author, are not in control of the file system, it is recommended to load the components manually.
We recommend doing this in the
AppConfig.ready()
hook of yourapps.py
:from django.apps import AppConfig\n\nclass MyAppConfig(AppConfig):\n default_auto_field = \"django.db.models.BigAutoField\"\n name = \"myapp\"\n\n # This is the code that gets run when user adds myapp\n # to Django's INSTALLED_APPS\n def ready(self) -> None:\n # Import the components that you want to make available\n # inside the templates.\n from myapp.templates import (\n menu,\n table,\n )\n
Note that you can also include any other startup logic within
AppConfig.ready()
.
And that's it! The next step is to publish it.
"},{"location":"concepts/advanced/authoring_component_libraries/#publishing-component-libraries","title":"Publishing component libraries","text":"Once you are ready to share your library, you need to build a distribution and then publish it to PyPI.
django_components uses the
build
utility to build a distribution:python -m build --sdist --wheel --outdir dist/ .\n
And to publish to PyPI, you can use
twine
(See Python user guide)twine upload --repository pypi dist/* -u __token__ -p <PyPI_TOKEN>\n
Notes on publishing:
- If you use components where the HTML / CSS / JS files are separate, you may need to define
MANIFEST.in
to include those files with the distribution (see user guide).
After the package has been published, all that remains is to install it in other django projects:
-
Install the package:
pip install myapp django_components\n
-
Add the package to
INSTALLED_APPS
INSTALLED_APPS = [\n ...\n \"django_components\",\n \"myapp\",\n]\n
-
Optionally add the template tags to the
builtins
, so you don't have to call{% load mytags %}
in every template:TEMPLATES = [\n {\n ...,\n 'OPTIONS': {\n 'builtins': [\n 'myapp.templatetags.mytags',\n ]\n },\n },\n]\n
-
And, at last, you can use the components in your own project!
{% my_menu title=\"Abc...\" %}\n Hello World!\n{% endmy_menu %}\n
In previous examples you could repeatedly see us using
@register()
to \"register\" the components. In this section we dive deeper into what it actually means and how you can manage (add or remove) components.As a reminder, we may have a component like this:
from django_components import Component, register\n\n@register(\"calendar\")\nclass Calendar(Component):\n template_file = \"template.html\"\n\n # This component takes one parameter, a date string to show in the template\n def get_context_data(self, date):\n return {\n \"date\": date,\n }\n
which we then render in the template as:
{% component \"calendar\" date=\"1970-01-01\" %}\n{% endcomponent %}\n
As you can see,
"},{"location":"concepts/advanced/component_registry/#what-is-componentregistry","title":"What is ComponentRegistry","text":"@register
links up the component class with the{% component %}
template tag. So when the template tag comes across a component called\"calendar\"
, it can look up it's class and instantiate it.The
@register
decorator is a shortcut for working with theComponentRegistry
.ComponentRegistry
manages which components can be used in the template tags.Each
ComponentRegistry
instance is associated with an instance of Django'sLibrary
. And Libraries are inserted into Django template using the{% load %}
tags.The
@register
decorator accepts an optional kwargregistry
, which specifies, theComponentRegistry
to register components into. If omitted, the defaultComponentRegistry
instance defined in django_components is used.my_registry = ComponentRegistry()\n\n@register(registry=my_registry)\nclass MyComponent(Component):\n ...\n
The default
ComponentRegistry
is associated with theLibrary
that you load when you call{% load component_tags %}
inside your template, or when you adddjango_components.templatetags.component_tags
to the template builtins.So when you register or unregister a component to/from a component registry, then behind the scenes the registry automatically adds/removes the component's template tags to/from the Library, so you can call the component from within the templates such as
"},{"location":"concepts/advanced/component_registry/#working-with-componentregistry","title":"Working with ComponentRegistry","text":"{% component \"my_comp\" %}
.The default
ComponentRegistry
instance can be imported as:from django_components import registry\n
You can use the registry to manually add/remove/get components:
"},{"location":"concepts/advanced/component_registry/#registering-components-to-custom-componentregistry","title":"Registering components to custom ComponentRegistry","text":"from django_components import registry\n\n# Register components\nregistry.register(\"button\", ButtonComponent)\nregistry.register(\"card\", CardComponent)\n\n# Get all or single\nregistry.all() # {\"button\": ButtonComponent, \"card\": CardComponent}\nregistry.get(\"card\") # CardComponent\n\n# Unregister single component\nregistry.unregister(\"card\")\n\n# Unregister all components\nregistry.clear()\n
If you are writing a component library to be shared with others, you may want to manage your own instance of
ComponentRegistry
and register components onto a differentLibrary
instance than the default one.The
Library
instance can be set at instantiation ofComponentRegistry
. If omitted, then the default Library instance from django_components is used.from django.template import Library\nfrom django_components import ComponentRegistry\n\nmy_library = Library(...)\nmy_registry = ComponentRegistry(library=my_library)\n
When you have defined your own
ComponentRegistry
, you can either register the components withmy_registry.register()
, or pass the registry to the@component.register()
decorator via theregistry
kwarg:from path.to.my.registry import my_registry\n\n@register(\"my_component\", registry=my_registry)\nclass MyComponent(Component):\n ...\n
NOTE: The Library instance can be accessed under
"},{"location":"concepts/advanced/component_registry/#componentregistry-settings","title":"ComponentRegistry settings","text":"library
attribute ofComponentRegistry
.When you are creating an instance of
ComponentRegistry
, you can define the components' behavior within the template.The registry accepts these settings:
context_behavior
tag_formatter
from django.template import Library\nfrom django_components import ComponentRegistry, RegistrySettings\n\nregister = library = django.template.Library()\ncomp_registry = ComponentRegistry(\n library=library,\n settings=RegistrySettings(\n context_behavior=\"isolated\",\n tag_formatter=\"django_components.component_formatter\",\n ),\n)\n
These settings are the same as the ones you can set for django_components.
In fact, when you set
COMPONENT.tag_formatter
orCOMPONENT.context_behavior
, these are forwarded to the defaultComponentRegistry
.This makes it possible to have multiple registries with different settings in one projects, and makes sharing of component libraries possible.
"},{"location":"concepts/advanced/hooks/","title":"Lifecycle hooks","text":"New in version 0.96
Component hooks are functions that allow you to intercept the rendering process at specific positions.
"},{"location":"concepts/advanced/hooks/#available-hooks","title":"Available hooks","text":"on_render_before
def on_render_before(\n self: Component,\n context: Context,\n template: Template\n) -> None:\n
Hook that runs just before the component's template is rendered.
You can use this hook to access or modify the context or the template:
def on_render_before(self, context, template) -> None:\n # Insert value into the Context\n context[\"from_on_before\"] = \":)\"\n\n # Append text into the Template\n template.nodelist.append(TextNode(\"FROM_ON_BEFORE\"))\n
on_render_after
def on_render_after(\n self: Component,\n context: Context,\n template: Template,\n content: str\n) -> None | str | SafeString:\n
Hook that runs just after the component's template was rendered. It receives the rendered output as the last argument.
You can use this hook to access the context or the template, but modifying them won't have any effect.
To override the content that gets rendered, you can return a string or SafeString from this hook:
"},{"location":"concepts/advanced/hooks/#component-hooks-example","title":"Component hooks example","text":"def on_render_after(self, context, template, content):\n # Prepend text to the rendered content\n return \"Chocolate cookie recipe: \" + content\n
You can use hooks together with provide / inject to create components that accept a list of items via a slot.
In the example below, each
tab_item
component will be rendered on a separate tab page, but they are all defined in the default slot of thetabs
component.See here for how it was done
"},{"location":"concepts/advanced/html_tragments/","title":"HTML fragments","text":"{% component \"tabs\" %}\n {% component \"tab_item\" header=\"Tab 1\" %}\n <p>\n hello from tab 1\n </p>\n {% component \"button\" %}\n Click me!\n {% endcomponent %}\n {% endcomponent %}\n\n {% component \"tab_item\" header=\"Tab 2\" %}\n Hello this is tab 2\n {% endcomponent %}\n{% endcomponent %}\n
Django-components provides a seamless integration with HTML fragments (HTML over the wire), whether you're using HTMX, AlpineJS, or vanilla JavaScript.
When you define a component that has extra JS or CSS, and you use django-components to render the fragment, django-components will:
- Automatically load the associated JS and CSS
- Ensure that JS is loaded and executed only once even if the fragment is inserted multiple times
Info
What are HTML fragments and \"HTML over the wire\"?
It is one of the methods for updating the state in the browser UI upon user interaction.
How it works is that:
- User makes an action - clicks a button or submits a form
- The action causes a request to be made from the client to the server.
- Server processes the request (e.g. form submission), and responds with HTML of some part of the UI (e.g. a new entry in a table).
- A library like HTMX, AlpineJS, or custom function inserts the new HTML into the correct place.
Components support two modes of rendering - As a \"document\" or as a \"fragment\".
What's the difference?
"},{"location":"concepts/advanced/html_tragments/#document-mode","title":"Document mode","text":"Document mode assumes that the rendered components will be embedded into the HTML of the initial page load. This means that:
- The JS and CSS is embedded into the HTML as
<script>
and<style>
tags (see JS and CSS output locations) - Django-components injects a JS script for managing JS and CSS assets
A component is rendered as a \"document\" when:
- It is embedded inside a template as
{% component %}
- It is rendered with
Component.render()
orComponent.render_to_response()
with thetype
kwarg set to\"document\"
(default)
Example:
"},{"location":"concepts/advanced/html_tragments/#fragment-mode","title":"Fragment mode","text":"MyTable.render(\n kwargs={...},\n)\n\n# or\n\nMyTable.render(\n kwargs={...},\n type=\"document\",\n)\n
Fragment mode assumes that the main HTML has already been rendered and loaded on the page. The component renders HTML that will be inserted into the page as a fragment, at a LATER time:
- JS and CSS is not directly embedded to avoid duplicately executing the same JS scripts. So template tags like
{% component_js_dependencies %}
inside of fragments are ignored. - Instead, django-components appends the fragment's content with a JSON
<script>
to trigger a call to its asset manager JS script, which will load the JS and CSS smartly. - The asset manager JS script is assumed to be already loaded on the page.
A component is rendered as \"fragment\" when:
- It is rendered with
Component.render()
orComponent.render_to_response()
with thetype
kwarg set to\"fragment\"
Example:
"},{"location":"concepts/advanced/html_tragments/#live-examples","title":"Live examples","text":"MyTable.render(\n kwargs={...},\n type=\"fragment\",\n)\n
For live interactive examples, start our demo project (
sampleproject
).Then navigate to these URLs:
/fragment/base/alpine
/fragment/base/htmx
/fragment/base/js
"},{"location":"concepts/advanced/html_tragments/#2-define-fragment-html","title":"2. Define fragment HTML","text":"[root]/components/demo.pyfrom django_components import Component, types\n\n# HTML into which a fragment will be loaded using HTMX\nclass MyPage(Component):\n def get(self, request):\n return self.render_to_response()\n\n template = \"\"\"\n {% load component_tags %}\n <!DOCTYPE html>\n <html>\n <head>\n {% component_css_dependencies %}\n <script src=\"https://unpkg.com/htmx.org@1.9.12\"></script>\n </head>\n <body>\n <div id=\"target\">OLD</div>\n\n <button\n hx-get=\"/mypage/frag\"\n hx-swap=\"outerHTML\"\n hx-target=\"#target\"\n >\n Click me!\n </button>\n\n {% component_js_dependencies %}\n </body>\n </html>\n \"\"\"\n
"},{"location":"concepts/advanced/html_tragments/#3-create-view-and-urls","title":"3. Create view and URLs","text":"[app]/urls.pyclass Frag(Component):\n def get(self, request):\n return self.render_to_response(\n # IMPORTANT: Don't forget `type=\"fragment\"`\n type=\"fragment\",\n )\n\n template = \"\"\"\n <div class=\"frag\">\n 123\n <span id=\"frag-text\"></span>\n </div>\n \"\"\"\n\n js = \"\"\"\n document.querySelector('#frag-text').textContent = 'xxx';\n \"\"\"\n\n css = \"\"\"\n .frag {\n background: blue;\n }\n \"\"\"\n
"},{"location":"concepts/advanced/html_tragments/#example-alpinejs","title":"Example - AlpineJS","text":""},{"location":"concepts/advanced/html_tragments/#1-define-document-html_1","title":"1. Define document HTML","text":"[root]/components/demo.pyfrom django.urls import path\n\nfrom components.demo import MyPage, Frag\n\nurlpatterns = [\n path(\"mypage/\", MyPage.as_view())\n path(\"mypage/frag\", Frag.as_view()),\n]\n
"},{"location":"concepts/advanced/html_tragments/#2-define-fragment-html_1","title":"2. Define fragment HTML","text":"[root]/components/demo.pyfrom django_components import Component, types\n\n# HTML into which a fragment will be loaded using AlpineJS\nclass MyPage(Component):\n def get(self, request):\n return self.render_to_response()\n\n template = \"\"\"\n {% load component_tags %}\n <!DOCTYPE html>\n <html>\n <head>\n {% component_css_dependencies %}\n <script defer src=\"https://unpkg.com/alpinejs\"></script>\n </head>\n <body x-data=\"{\n htmlVar: 'OLD',\n loadFragment: function () {\n const url = '/mypage/frag';\n fetch(url)\n .then(response => response.text())\n .then(html => {\n this.htmlVar = html;\n });\n }\n }\">\n <div id=\"target\" x-html=\"htmlVar\">OLD</div>\n\n <button @click=\"loadFragment\">\n Click me!\n </button>\n\n {% component_js_dependencies %}\n </body>\n </html>\n \"\"\"\n
"},{"location":"concepts/advanced/html_tragments/#3-create-view-and-urls_1","title":"3. Create view and URLs","text":"[app]/urls.pyclass Frag(Component):\n def get(self, request):\n # IMPORTANT: Don't forget `type=\"fragment\"`\n return self.render_to_response(\n type=\"fragment\",\n )\n\n # NOTE: We wrap the actual fragment in a template tag with x-if=\"false\" to prevent it\n # from being rendered until we have registered the component with AlpineJS.\n template = \"\"\"\n <template x-if=\"false\" data-name=\"frag\">\n <div class=\"frag\">\n 123\n <span x-data=\"frag\" x-text=\"fragVal\">\n </span>\n </div>\n </template>\n \"\"\"\n\n js = \"\"\"\n Alpine.data('frag', () => ({\n fragVal: 'xxx',\n }));\n\n // Now that the component has been defined in AlpineJS, we can \"activate\"\n // all instances where we use the `x-data=\"frag\"` directive.\n document.querySelectorAll('[data-name=\"frag\"]').forEach((el) => {\n el.setAttribute('x-if', 'true');\n });\n \"\"\"\n\n css = \"\"\"\n .frag {\n background: blue;\n }\n \"\"\"\n
"},{"location":"concepts/advanced/html_tragments/#example-vanilla-js","title":"Example - Vanilla JS","text":""},{"location":"concepts/advanced/html_tragments/#1-define-document-html_2","title":"1. Define document HTML","text":"[root]/components/demo.pyfrom django.urls import path\n\nfrom components.demo import MyPage, Frag\n\nurlpatterns = [\n path(\"mypage/\", MyPage.as_view())\n path(\"mypage/frag\", Frag.as_view()),\n]\n
"},{"location":"concepts/advanced/html_tragments/#2-define-fragment-html_2","title":"2. Define fragment HTML","text":"[root]/components/demo.pyfrom django_components import Component, types\n\n# HTML into which a fragment will be loaded using JS\nclass MyPage(Component):\n def get(self, request):\n return self.render_to_response()\n\n template = \"\"\"\n {% load component_tags %}\n <!DOCTYPE html>\n <html>\n <head>\n {% component_css_dependencies %}\n </head>\n <body>\n <div id=\"target\">OLD</div>\n\n <button>\n Click me!\n </button>\n <script>\n const url = `/mypage/frag`;\n document.querySelector('#loader').addEventListener('click', function () {\n fetch(url)\n .then(response => response.text())\n .then(html => {\n document.querySelector('#target').outerHTML = html;\n });\n });\n </script>\n\n {% component_js_dependencies %}\n </body>\n </html>\n \"\"\"\n
"},{"location":"concepts/advanced/html_tragments/#3-create-view-and-urls_2","title":"3. Create view and URLs","text":"[app]/urls.pyclass Frag(Component):\n def get(self, request):\n return self.render_to_response(\n # IMPORTANT: Don't forget `type=\"fragment\"`\n type=\"fragment\",\n )\n\n template = \"\"\"\n <div class=\"frag\">\n 123\n <span id=\"frag-text\"></span>\n </div>\n \"\"\"\n\n js = \"\"\"\n document.querySelector('#frag-text').textContent = 'xxx';\n \"\"\"\n\n css = \"\"\"\n .frag {\n background: blue;\n }\n \"\"\"\n
"},{"location":"concepts/advanced/provide_inject/","title":"Prop drilling and provide / inject","text":"from django.urls import path\n\nfrom components.demo import MyPage, Frag\n\nurlpatterns = [\n path(\"mypage/\", MyPage.as_view())\n path(\"mypage/frag\", Frag.as_view()),\n]\n
New in version 0.80:
Django components supports the provide / inject or ContextProvider pattern with the combination of:
{% provide %}
taginject()
method of theComponent
class
Prop drilling refers to a scenario in UI development where you need to pass data through many layers of a component tree to reach the nested components that actually need the data.
Normally, you'd use props to send data from a parent component to its children. However, this straightforward method becomes cumbersome and inefficient if the data has to travel through many levels or if several components scattered at different depths all need the same piece of information.
This results in a situation where the intermediate components, which don't need the data for their own functioning, end up having to manage and pass along these props. This clutters the component tree and makes the code verbose and harder to manage.
A neat solution to avoid prop drilling is using the \"provide and inject\" technique.
With provide / inject, a parent component acts like a data hub for all its descendants. This setup allows any component, no matter how deeply nested it is, to access the required data directly from this centralized provider without having to messily pass props down the chain. This approach significantly cleans up the code and makes it easier to maintain.
This feature is inspired by Vue's Provide / Inject and React's Context / useContext.
"},{"location":"concepts/advanced/provide_inject/#how-to-use-provide-inject","title":"How to use provide / inject","text":"As the name suggest, using provide / inject consists of 2 steps
- Providing data
- Injecting provided data
For examples of advanced uses of provide / inject, see this discussion.
"},{"location":"concepts/advanced/provide_inject/#using-provide-tag","title":"Using{% provide %}
tag","text":"First we use the
{% provide %}
tag to define the data we want to \"provide\" (make available).{% provide \"my_data\" key=\"hi\" another=123 %}\n {% component \"child\" / %} <--- Can access \"my_data\"\n{% endprovide %}\n\n{% component \"child\" / %} <--- Cannot access \"my_data\"\n
Notice that the
provide
tag REQUIRES a name as a first argument. This is the key by which we can then access the data passed to this tag.provide
tag name must resolve to a valid identifier (AKA a valid Python variable name).Once you've set the name, you define the data you want to \"provide\" by passing it as keyword arguments. This is similar to how you pass data to the
{% with %}
tag.NOTE: Kwargs passed to
{% provide %}
are NOT added to the context. In the example below, the{{ key }}
won't render anything:{% provide \"my_data\" key=\"hi\" another=123 %}\n {{ key }}\n{% endprovide %}\n
Similarly to slots and fills, also provide's name argument can be set dynamically via a variable, a template expression, or a spread operator:
"},{"location":"concepts/advanced/provide_inject/#using-inject-method","title":"Using{% provide name=name ... %}\n ...\n{% provide %}\n</table>\n
inject()
method","text":"To \"inject\" (access) the data defined on the
provide
tag, you can use theinject()
method inside ofget_context_data()
.For a component to be able to \"inject\" some data, the component (
{% component %}
tag) must be nested inside the{% provide %}
tag.In the example from previous section, we've defined two kwargs:
key=\"hi\" another=123
. That means that if we now inject\"my_data\"
, we get an object with 2 attributes -key
andanother
.class ChildComponent(Component):\n def get_context_data(self):\n my_data = self.inject(\"my_data\")\n print(my_data.key) # hi\n print(my_data.another) # 123\n return {}\n
First argument to
inject
is the key (or name) of the provided data. This must match the string that you used in theprovide
tag. If no provider with given key is found,inject
raises aKeyError
.To avoid the error, you can pass a second argument to
inject
to which will act as a default value, similar todict.get(key, default)
:class ChildComponent(Component):\n def get_context_data(self):\n my_data = self.inject(\"invalid_key\", DEFAULT_DATA)\n assert my_data == DEFAUKT_DATA\n return {}\n
The instance returned from
inject()
is a subclass ofNamedTuple
, so the instance is immutable. This ensures that the data returned frominject
will always have all the keys that were passed to theprovide
tag.NOTE:
"},{"location":"concepts/advanced/provide_inject/#full-example","title":"Full example","text":"inject()
works strictly only inget_context_data
. If you try to call it from elsewhere, it will raise an error.@register(\"child\")\nclass ChildComponent(Component):\n template = \"\"\"\n <div> {{ my_data.key }} </div>\n <div> {{ my_data.another }} </div>\n \"\"\"\n\n def get_context_data(self):\n my_data = self.inject(\"my_data\", \"default\")\n return {\"my_data\": my_data}\n\ntemplate_str = \"\"\"\n {% load component_tags %}\n {% provide \"my_data\" key=\"hi\" another=123 %}\n {% component \"child\" / %}\n {% endprovide %}\n\"\"\"\n
renders:
"},{"location":"concepts/advanced/rendering_js_css/","title":"Rendering JS / CSS","text":""},{"location":"concepts/advanced/rendering_js_css/#js-and-css-output-locations","title":"JS and CSS output locations","text":"<div>hi</div>\n<div>123</div>\n
If:
- Your components use JS and CSS via any of:
Component.css
Component.js
Component.Media.css
Component.Media.js
- And you use the
ComponentDependencyMiddleware
middleware
Then, by default, the components' JS and CSS will be automatically inserted into the HTML:
- CSS styles will be inserted at the end of the
<head>
- JS scripts will be inserted at the end of the
<body>
If you want to place the dependencies elsewhere in the HTML, you can override the locations by inserting following Django template tags:
{% component_js_dependencies %}
- Set new location(s) for JS scripts{% component_css_dependencies %}
- Set new location(s) for CSS styles
So if you have a component with JS and CSS:
from django_components import Component, types\n\nclass MyButton(Component):\n template: types.django_html = \"\"\"\n <button class=\"my-button\">\n Click me!\n </button>\n \"\"\"\n js: types.js = \"\"\"\n for (const btnEl of document.querySelectorAll(\".my-button\")) {\n btnEl.addEventListener(\"click\", () => {\n console.log(\"BUTTON CLICKED!\");\n });\n }\n \"\"\"\n css: types.css \"\"\"\n .my-button {\n background: green;\n }\n \"\"\"\n\n class Media:\n js = [\"/extra/script.js\"]\n css = [\"/extra/style.css\"]\n
Then the JS from
MyButton.js
andMyButton.Media.js
will be rendered at the default place, or in{% component_js_dependencies %}
.And the CSS from
MyButton.css
andMyButton.Media.css
will be rendered at the default place, or in{% component_css_dependencies %}
.And if you don't specify
{% component_dependencies %}
tags, it is the equivalent of:
"},{"location":"concepts/advanced/rendering_js_css/#setting-up-the-middleware","title":"Setting up the middleware","text":"<!doctype html>\n<html>\n <head>\n <title>MyPage</title>\n ...\n {% component_css_dependencies %}\n </head>\n <body>\n <main>\n ...\n </main>\n {% component_js_dependencies %}\n </body>\n</html>\n
ComponentDependencyMiddleware
is a Django middleware designed to manage and inject CSS / JS dependencies of rendered components dynamically. It ensures that only the necessary stylesheets and scripts are loaded in your HTML responses, based on the components used in your Django templates.To set it up, add the middleware to your
MIDDLEWARE
insettings.py
:
"},{"location":"concepts/advanced/rendering_js_css/#render_dependencies-and-rendering-js-css-without-the-middleware","title":"MIDDLEWARE = [\n # ... other middleware classes ...\n 'django_components.middleware.ComponentDependencyMiddleware'\n # ... other middleware classes ...\n]\n
render_dependencies
and rendering JS / CSS without the middleware","text":"For most scenarios, using the
ComponentDependencyMiddleware
middleware will be just fine.However, this section is for you if you want to:
- Render HTML that will NOT be sent as a server response
- Insert pre-rendered HTML into another component
- Render HTML fragments (partials)
Every time there is an HTML string that has parts which were rendered using components, and any of those components has JS / CSS, then this HTML string MUST be processed with
render_dependencies()
.It is actually
"},{"location":"concepts/advanced/rendering_js_css/#render-js-css-without-the-middleware","title":"Render JS / CSS without the middleware","text":"render_dependencies()
that finds all used components in the HTML string, and inserts the component's JS and CSS into{% component_dependencies %}
tags, or at the default locations.The truth is that the
ComponentDependencyMiddleware
middleware just callsrender_dependencies()
, passing in the HTML content. So if you render a template that contained{% component %}
tags, you MUST pass the result throughrender_dependencies()
. And the middleware is just one of the options.Here is how you can achieve the same, without the middleware, using
render_dependencies()
:from django.template.base import Template\nfrom django.template.context import Context\nfrom django_component import render_dependencies\n\ntemplate = Template(\"\"\"\n {% load component_tags %}\n <!doctype html>\n <html>\n <head>\n <title>MyPage</title>\n </head>\n <body>\n <main>\n {% component \"my_button\" %}\n Click me!\n {% endcomponent %}\n </main>\n </body>\n </html>\n\"\"\")\n\nrendered = template.render(Context())\nrendered = render_dependencies(rendered)\n
Same applies if you render a template using Django's
django.shortcuts.render
:from django.shortcuts import render\n\ndef my_view(request):\n rendered = render(request, \"pages/home.html\")\n rendered = render_dependencies(rendered)\n return rendered\n
Alternatively, when you render HTML with
Component.render()
orComponent.render_to_response()
, these, by default, callrender_dependencies()
for you, so you don't have to:
"},{"location":"concepts/advanced/rendering_js_css/#inserting-pre-rendered-html-into-another-component","title":"Inserting pre-rendered HTML into another component","text":"from django_components import Component\n\nclass MyButton(Component):\n ...\n\n# No need to call `render_dependencies()`\nrendered = MyButton.render()\n
In previous section we've shown that
render_dependencies()
does NOT need to be called when you render a component viaComponent.render()
.API of django_components makes it possible to compose components in a \"React-like\" way, where we pre-render a piece of HTML and then insert it into a larger structure.
To do this, you must add
render_dependencies=False
to the nested components:card_actions = CardActions.render(\n kwargs={\"editable\": editable},\n render_dependencies=False,\n)\n\ncard = Card.render(\n slots={\"actions\": card_actions},\n render_dependencies=False,\n)\n\npage = MyPage.render(\n slots={\"card\": card},\n)\n
Why is
render_dependencies=False
required?This is a technical limitation of the current implementation.
As mentioned earlier, each time we call
Component.render()
, we also callrender_dependencies()
.However, there is a problem here - When we call
render_dependencies()
insideCardActions.render()
, we extract and REMOVE the info on components' JS and CSS from the HTML. But the template ofCardActions
contains no{% component_depedencies %}
tags, and nor<head>
nor<body>
HTML tags. So the component's JS and CSS will NOT be inserted, and will be lost.To work around this, you must set
"},{"location":"concepts/advanced/rendering_js_css/#summary","title":"Summary","text":"render_dependencies=False
when rendering pieces of HTML withComponent.render()
and inserting them into larger structures.- Every time you render HTML that contained components, you have to call
render_dependencies()
on the rendered output. - There are several ways to call
render_dependencies()
:- Using the
ComponentDependencyMiddleware
middleware - Rendering the HTML by calling
Component.render()
withrender_dependencies=True
(default) - Rendering the HTML by calling
Component.render_to_response()
(always renders dependencies) - Directly passing rendered HTML to
render_dependencies()
- Using the
- If you pre-render one component to pass it into another, the pre-rendered component must be rendered with
render_dependencies=False
.
New in version 0.89
By default, components are rendered using the pair of
{% component %}
/{% endcomponent %}
template tags:{% component \"button\" href=\"...\" disabled %}\nClick me!\n{% endcomponent %}\n\n{# or #}\n\n{% component \"button\" href=\"...\" disabled / %}\n
You can change this behaviour in the settings under the
COMPONENTS.tag_formatter
.For example, if you set the tag formatter to
django_components.component_shorthand_formatter
then the components' names will be used as the template tags:
"},{"location":"concepts/advanced/tag_formatter/#available-tagformatters","title":"Available TagFormatters","text":"{% button href=\"...\" disabled %}\n Click me!\n{% endbutton %}\n\n{# or #}\n\n{% button href=\"...\" disabled / %}\n
django_components provides following predefined TagFormatters:
ComponentFormatter
(django_components.component_formatter
)
Default
Uses the
component
andendcomponent
tags, and the component name is gives as the first positional argument.Example as block:
{% component \"button\" href=\"...\" %}\n {% fill \"content\" %}\n ...\n {% endfill %}\n{% endcomponent %}\n
Example as inlined tag:
{% component \"button\" href=\"...\" / %}\n
ShorthandComponentFormatter
(django_components.component_shorthand_formatter
)
Uses the component name as start tag, and
end<component_name>
as an end tag.Example as block:
{% button href=\"...\" %}\n Click me!\n{% endbutton %}\n
Example as inlined tag:
"},{"location":"concepts/advanced/tag_formatter/#writing-your-own-tagformatter","title":"Writing your own TagFormatter","text":""},{"location":"concepts/advanced/tag_formatter/#background","title":"Background","text":"{% button href=\"...\" / %}\n
First, let's discuss how TagFormatters work, and how components are rendered in django_components.
When you render a component with
{% component %}
(or your own tag), the following happens:component
must be registered as a Django's template tag- Django triggers django_components's tag handler for tag
component
. - The tag handler passes the tag contents for pre-processing to
TagFormatter.parse()
.
So if you render this:
{% component \"button\" href=\"...\" disabled %}\n{% endcomponent %}\n
Then
TagFormatter.parse()
will receive a following input:[\"component\", '\"button\"', 'href=\"...\"', 'disabled']\n
TagFormatter
extracts the component name and the remaining input.
So, given the above,
TagFormatter.parse()
returns the following:TagResult(\n component_name=\"button\",\n tokens=['href=\"...\"', 'disabled']\n)\n
- The tag handler resumes, using the tokens returned from
TagFormatter
.
So, continuing the example, at this point the tag handler practically behaves as if you rendered:
{% component href=\"...\" disabled %}\n
- Tag handler looks up the component
button
, and passes the args, kwargs, and slots to it.
TagFormatter
handles following parts of the process above:-
Generates start/end tags, given a component. This is what you then call from within your template as
{% component %}
. -
When you
{% component %}
, tag formatter pre-processes the tag contents, so it can link back the custom template tag to the right component.
To do so, subclass from
TagFormatterABC
and implement following method:start_tag
end_tag
parse
For example, this is the implementation of
ShorthandComponentFormatter
class ShorthandComponentFormatter(TagFormatterABC):\n # Given a component name, generate the start template tag\n def start_tag(self, name: str) -> str:\n return name # e.g. 'button'\n\n # Given a component name, generate the start template tag\n def end_tag(self, name: str) -> str:\n return f\"end{name}\" # e.g. 'endbutton'\n\n # Given a tag, e.g.\n # `{% button href=\"...\" disabled %}`\n #\n # The parser receives:\n # `['button', 'href=\"...\"', 'disabled']`\n def parse(self, tokens: List[str]) -> TagResult:\n tokens = [*tokens]\n name = tokens.pop(0)\n return TagResult(\n name, # e.g. 'button'\n tokens # e.g. ['href=\"...\"', 'disabled']\n )\n
That's it! And once your
"},{"location":"concepts/advanced/template_tags/","title":"Custom template tags","text":"TagFormatter
is ready, don't forget to update the settings!Template tags introduced by django-components, such as
{% component %}
and{% slot %}
, offer additional features over the default Django template tags:- Self-closing tags
{% mytag / %}
- Allowing the use of
:
,-
(and more) in keys - Spread operator
...
- Using template tags as inputs to other template tags
- Flat definition of dictionaries
attr:key=val
- Function-like input validation
You too can easily create custom template tags that use the above features.
"},{"location":"concepts/advanced/template_tags/#defining-template-tags-with-template_tag","title":"Defining template tags with@template_tag
","text":"The simplest way to create a custom template tag is using the
template_tag
decorator. This decorator allows you to define a template tag by just writing a function that returns the rendered content.from django.template import Context, Library\nfrom django_components import BaseNode, template_tag\n\nlibrary = Library()\n\n@template_tag(\n library,\n tag=\"mytag\",\n end_tag=\"endmytag\",\n allowed_flags=[\"required\"]\n)\ndef mytag(node: BaseNode, context: Context, name: str, **kwargs) -> str:\n return f\"Hello, {name}!\"\n
This will allow you to use the tag in your templates like this:
"},{"location":"concepts/advanced/template_tags/#parameters","title":"Parameters","text":"{% mytag name=\"John\" %}\n{% endmytag %}\n\n{# or with self-closing syntax #}\n{% mytag name=\"John\" / %}\n\n{# or with flags #}\n{% mytag name=\"John\" required %}\n{% endmytag %}\n
The
@template_tag
decorator accepts the following parameters:library
: The Django template library to register the tag withtag
: The name of the template tag (e.g.\"mytag\"
for{% mytag %}
)end_tag
: Optional. The name of the end tag (e.g.\"endmytag\"
for{% endmytag %}
)allowed_flags
: Optional. List of flags that can be used with the tag (e.g.[\"required\"]
for{% mytag required %}
)
The function decorated with
@template_tag
must accept at least two arguments:node
: The node instance (we'll explain this in detail in the next section)context
: The Django template context
Any additional parameters in your function's signature define what inputs your template tag accepts. For example:
@template_tag(library, tag=\"greet\")\ndef greet(\n node: BaseNode,\n context: Context,\n name: str, # required positional argument\n count: int = 1, # optional positional argument\n *, # keyword-only arguments marker\n msg: str, # required keyword argument\n mode: str = \"default\", # optional keyword argument\n) -> str:\n return f\"{msg}, {name}!\" * count\n
This allows the tag to be used like:
{# All parameters #}\n{% greet \"John\" count=2 msg=\"Hello\" mode=\"custom\" %}\n\n{# Only required parameters #}\n{% greet \"John\" msg=\"Hello\" %}\n\n{# Missing required parameter - will raise error #}\n{% greet \"John\" %} {# Error: missing 'msg' #}\n
When you pass input to a template tag, it behaves the same way as if you passed the input to a function:
- If required parameters are missing, an error is raised
- If unexpected parameters are passed, an error is raised
To accept keys that are not valid Python identifiers (e.g.
data-id
), or would conflict with Python keywords (e.g.is
), you can use the**kwargs
syntax:@template_tag(library, tag=\"greet\")\ndef greet(\n node: BaseNode,\n context: Context,\n **kwargs,\n) -> str:\n attrs = kwargs.copy()\n is_var = attrs.pop(\"is\", None)\n attrs_str = \" \".join(f'{k}=\"{v}\"' for k, v in attrs.items())\n\n return mark_safe(f\"\"\"\n <div {attrs_str}>\n Hello, {is_var}!\n </div>\n \"\"\")\n
This allows you to use the tag like this:
"},{"location":"concepts/advanced/template_tags/#defining-template-tags-with-basenode","title":"Defining template tags with{% greet is=\"John\" data-id=\"123\" %}\n
BaseNode
","text":"For more control over your template tag, you can subclass
BaseNode
directly instead of using the decorator. This gives you access to additional features like the node's internal state and parsing details.
"},{"location":"concepts/advanced/template_tags/#node-properties","title":"Node properties","text":"from django_components import BaseNode\n\nclass GreetNode(BaseNode):\n tag = \"greet\"\n end_tag = \"endgreet\"\n allowed_flags = [\"required\"]\n\n def render(self, context: Context, name: str, **kwargs) -> str:\n # Access node properties\n if self.flags[\"required\"]:\n return f\"Required greeting: Hello, {name}!\"\n return f\"Hello, {name}!\"\n\n# Register the node\nGreetNode.register(library)\n
When using
BaseNode
, you have access to several useful properties:node_id
: A unique identifier for this node instanceflags
: Dictionary of flag values (e.g.{\"required\": True}
)params
: List of raw parameters passed to the tagnodelist
: The template nodes between the start and end tagsactive_flags
: List of flags that are currently set to True
This is what the
"},{"location":"concepts/advanced/template_tags/#rendering-content-between-tags","title":"Rendering content between tags","text":"node
parameter in the@template_tag
decorator gives you access to - it's the instance of the node class that was automatically created for your template tag.When your tag has an end tag, you can access and render the content between the tags using
nodelist
:
"},{"location":"concepts/advanced/template_tags/#unregistering-nodes","title":"Unregistering nodes","text":"class WrapNode(BaseNode):\n tag = \"wrap\"\n end_tag = \"endwrap\"\n\n def render(self, context: Context, tag: str = \"div\", **attrs) -> str:\n # Render the content between tags\n inner = self.nodelist.render(context)\n attrs_str = \" \".join(f'{k}=\"{v}\"' for k, v in attrs.items())\n return f\"<{tag} {attrs_str}>{inner}</{tag}>\"\n\n# Usage:\n{% wrap tag=\"section\" class=\"content\" %}\n Hello, world!\n{% endwrap %}\n
You can unregister a node from a library using the
unregister
method:GreetNode.unregister(library)\n
This is particularly useful in testing when you want to clean up after registering temporary tags.
"},{"location":"concepts/advanced/typing_and_validation/","title":"Typing and validation","text":""},{"location":"concepts/advanced/typing_and_validation/#adding-type-hints-with-generics","title":"Adding type hints with Generics","text":"New in version 0.92
The
Component
class optionally accepts type parameters that allow you to specify the types of args, kwargs, slots, and data:class Button(Component[Args, Kwargs, Slots, Data, JsData, CssData]):\n ...\n
Args
- Must be aTuple
orAny
Kwargs
- Must be aTypedDict
orAny
Data
- Must be aTypedDict
orAny
Slots
- Must be aTypedDict
orAny
Here's a full example:
from typing import NotRequired, Tuple, TypedDict, SlotContent, SlotFunc\n\n# Positional inputs\nArgs = Tuple[int, str]\n\n# Kwargs inputs\nclass Kwargs(TypedDict):\n variable: str\n another: int\n maybe_var: NotRequired[int] # May be ommited\n\n# Data returned from `get_context_data`\nclass Data(TypedDict):\n variable: str\n\n# The data available to the `my_slot` scoped slot\nclass MySlotData(TypedDict):\n value: int\n\n# Slots\nclass Slots(TypedDict):\n # Use SlotFunc for slot functions.\n # The generic specifies the `data` dictionary\n my_slot: NotRequired[SlotFunc[MySlotData]]\n # SlotContent == Union[str, SafeString]\n another_slot: SlotContent\n\nclass Button(Component[Args, Kwargs, Slots, Data, JsData, CssData]):\n def get_context_data(self, variable, another):\n return {\n \"variable\": variable,\n }\n
When you then call
Component.render
orComponent.render_to_response
, you will get type hints:
"},{"location":"concepts/advanced/typing_and_validation/#usage-for-python-311","title":"Usage for Python <3.11","text":"Button.render(\n # Error: First arg must be `int`, got `float`\n args=(1.25, \"abc\"),\n # Error: Key \"another\" is missing\n kwargs={\n \"variable\": \"text\",\n },\n)\n
On Python 3.8-3.10, use
typing_extensions
from typing_extensions import TypedDict, NotRequired\n
Additionally on Python 3.8-3.9, also import
annotations
:from __future__ import annotations\n
Moreover, on 3.10 and less, you may not be able to use
NotRequired
, and instead you will need to mark either all keys are required, or all keys as optional, using TypeDict'stotal
kwarg.See PEP-655 for more info.
"},{"location":"concepts/advanced/typing_and_validation/#passing-additional-args-or-kwargs","title":"Passing additional args or kwargs","text":"You may have a function that supports any number of args or kwargs:
def get_context_data(self, *args, **kwargs):\n ...\n
This is not supported with the typed components.
As a workaround:
- For
*args
, set a positional argument that accepts a list of values:
# Tuple of one member of list of strings\nArgs = Tuple[List[str]]\n
- For
*kwargs
, set a keyword argument that accepts a dictionary of values:
"},{"location":"concepts/advanced/typing_and_validation/#handling-no-args-or-no-kwargs","title":"Handling no args or no kwargs","text":"class Kwargs(TypedDict):\n variable: str\n another: int\n # Pass any extra keys under `extra`\n extra: Dict[str, any]\n
To declare that a component accepts no Args, Kwargs, etc, you can use
EmptyTuple
andEmptyDict
types:
"},{"location":"concepts/advanced/typing_and_validation/#runtime-input-validation-with-types","title":"Runtime input validation with types","text":"from django_components import Component, EmptyDict, EmptyTuple\n\nArgs = EmptyTuple\nKwargs = Data = Slots = EmptyDict\n\nclass Button(Component[Args, Kwargs, Slots, Data, JsData, CssData]):\n ...\n
New in version 0.96
NOTE: Kwargs, slots, and data validation is supported only for Python >=3.11
In Python 3.11 and later, when you specify the component types, you will get also runtime validation of the inputs you pass to
Component.render
orComponent.render_to_response
.So, using the example from before, if you ignored the type errors and still ran the following code:
Button.render(\n # Error: First arg must be `int`, got `float`\n args=(1.25, \"abc\"),\n # Error: Key \"another\" is missing\n kwargs={\n \"variable\": \"text\",\n },\n)\n
This would raise a
TypeError
:Component 'Button' expected positional argument at index 0 to be <class 'int'>, got 1.25 of type <class 'float'>\n
In case you need to skip these errors, you can either set the faulty member to
Any
, e.g.:# Changed `int` to `Any`\nArgs = Tuple[Any, str]\n
Or you can replace
Args
withAny
altogether, to skip the validation of args:# Replaced `Args` with `Any`\nclass Button(Component[Any, Kwargs, Slots, Data, JsData, CssData]):\n ...\n
Same applies to kwargs, data, and slots.
"},{"location":"concepts/fundamentals/access_component_input/","title":"Accessing component inputs","text":"When you call
Component.render
orComponent.render_to_response
, the inputs to these methods can be accessed from within the instance underself.input
.This means that you can use
self.input
inside:get_context_data
get_template_name
get_template
on_render_before
on_render_after
self.input
is only defined during the execution ofComponent.render
, and raises aRuntimeError
when called outside of this context.self.input
has the same fields as the input toComponent.render
:class TestComponent(Component):\n def get_context_data(self, var1, var2, variable, another, **attrs):\n assert self.input.args == (123, \"str\")\n assert self.input.kwargs == {\"variable\": \"test\", \"another\": 1}\n assert self.input.slots == {\"my_slot\": \"MY_SLOT\"}\n assert isinstance(self.input.context, Context)\n\n return {\n \"variable\": variable,\n }\n\nrendered = TestComponent.render(\n kwargs={\"variable\": \"test\", \"another\": 1},\n args=(123, \"str\"),\n slots={\"my_slot\": \"MY_SLOT\"},\n)\n
NOTE: The slots in
"},{"location":"concepts/fundamentals/autodiscovery/","title":"Autodiscovery","text":"self.input.slots
are normalized to slot functions.Every component that you want to use in the template with the
{% component %}
tag needs to be registered with theComponentRegistry
. Normally, we use the@register
decorator for that:from django_components import Component, register\n\n@register(\"calendar\")\nclass Calendar(Component):\n ...\n
But for the component to be registered, the code needs to be executed - and for that, the file needs to be imported as a module.
One way to do that is by importing all your components in
apps.py
:from django.apps import AppConfig\n\nclass MyAppConfig(AppConfig):\n name = \"my_app\"\n\n def ready(self) -> None:\n from components.card.card import Card\n from components.list.list import List\n from components.menu.menu import Menu\n from components.button.button import Button\n ...\n
However, there's a simpler way!
By default, the Python files in the
COMPONENTS.dirs
directories (and app-level[app]/components/
) are auto-imported in order to auto-register the components.Autodiscovery occurs when Django is loaded, during the
AppConfig.ready
hook of theapps.py
file.If you are using autodiscovery, keep a few points in mind:
- Avoid defining any logic on the module-level inside the
components
dir, that you would not want to run anyway. - Components inside the auto-imported files still need to be registered with
@register
- Auto-imported component files must be valid Python modules, they must use suffix
.py
, and module name should follow PEP-8. - Subdirectories and files starting with an underscore
_
(except__init__.py
) are ignored.
Autodiscovery can be disabled in the settings.
"},{"location":"concepts/fundamentals/autodiscovery/#manually-trigger-autodiscovery","title":"Manually trigger autodiscovery","text":"Autodiscovery can be also triggered manually, using the
autodiscover
function. This is useful if you want to run autodiscovery at a custom point of the lifecycle:from django_components import autodiscover\n\nautodiscover()\n
To get the same list of modules that
autodiscover()
would return, but without importing them, useget_component_files()
:
"},{"location":"concepts/fundamentals/component_context_scope/","title":"Component context and scope","text":"from django_components import get_component_files\n\nmodules = get_component_files(\".py\")\n
By default, context variables are passed down the template as in regular Django - deeper scopes can access the variables from the outer scopes. So if you have several nested forloops, then inside the deep-most loop you can access variables defined by all previous loops.
With this in mind, the
{% component %}
tag behaves similarly to{% include %}
tag - inside the component tag, you can access all variables that were defined outside of it.And just like with
{% include %}
, if you don't want a specific component template to have access to the parent context, addonly
to the{% component %}
tag:{% component \"calendar\" date=\"2015-06-19\" only / %}\n
NOTE:
{% csrf_token %}
tags need access to the top-level context, and they will not function properly if they are rendered in a component that is called with theonly
modifier.If you find yourself using the
only
modifier often, you can set the context_behavior option to\"isolated\"
, which automatically applies theonly
modifier. This is useful if you want to make sure that components don't accidentally access the outer context.Components can also access the outer context in their context methods like
"},{"location":"concepts/fundamentals/component_context_scope/#example-of-accessing-outer-context","title":"Example of Accessing Outer Context","text":"get_context_data
by accessing the propertyself.outer_context
.<div>\n {% component \"calender\" / %}\n</div>\n
Assuming that the rendering context has variables such as
date
, you can useself.outer_context
to access them from withinget_context_data
. Here's how you might implement it:class Calender(Component):\n\n ...\n\n def get_context_data(self):\n outer_field = self.outer_context[\"date\"]\n return {\n \"date\": outer_fields,\n }\n
However, as a best practice, it\u2019s recommended not to rely on accessing the outer context directly through
"},{"location":"concepts/fundamentals/component_context_scope/#context-behavior","title":"Context behavior","text":"self.outer_context
. Instead, explicitly pass the variables to the component. For instance, continue passing the variables in the component tag as shown in the previous examples.django_components supports both Django and Vue-like behavior when it comes to passing data to and through components. This can be configured in context_behavior.
This has two modes:
-
\"django\"
The default Django template behavior.
Inside the
{% fill %}
tag, the context variables you can access are a union of:- All the variables that were OUTSIDE the fill tag, including any\\
{% with %}
tags. - Any loops (
{% for ... %}
) that the{% fill %}
tag is part of. - Data returned from
Component.get_context_data()
of the component that owns the fill tag.
- All the variables that were OUTSIDE the fill tag, including any\\
-
\"isolated\"
Similar behavior to Vue or React, this is useful if you want to make sure that components don't accidentally access variables defined outside of the component.
Inside the
{% fill %}
tag, you can ONLY access variables from 2 places:- Any loops (
{% for ... %}
) that the{% fill %}
tag is part of. Component.get_context_data()
of the component which defined the template (AKA the \"root\" component).
- Any loops (
Warning
Notice that the component whose
get_context_data()
we use inside{% fill %}
is NOT the same across the two modes!Consider this example:
class Outer(Component):\n template = \\\"\\\"\\\"\n <div>\n {% component \"inner\" %}\n {% fill \"content\" %}\n {{ my_var }}\n {% endfill %}\n {% endcomponent %}\n </div>\n \\\"\\\"\\\"\n
-
\"django\"
-my_var
has access to data fromget_context_data()
of bothInner
andOuter
. If there are variables defined in both, thenInner
overshadowsOuter
. -
\"isolated\"
-my_var
has access to data fromget_context_data()
of ONLYOuter
.
Given this template:
@register(\"root_comp\")\nclass RootComp(Component):\n template = \"\"\"\n {% with cheese=\"feta\" %}\n {% component 'my_comp' %}\n {{ my_var }} # my_var\n {{ cheese }} # cheese\n {% endcomponent %}\n {% endwith %}\n \"\"\"\n\n def get_context_data(self):\n return { \"my_var\": 123 }\n
Then if
get_context_data()
of the component\"my_comp\"
returns following data:{ \"my_var\": 456 }\n
Then the template will be rendered as:
456 # my_var\nfeta # cheese\n
Because
\"my_comp\"
overshadows the outer variable\"my_var\"
, so{{ my_var }}
equals456
.And variable
"},{"location":"concepts/fundamentals/component_context_scope/#example-isolated","title":"Example \"isolated\"","text":"\"cheese\"
equalsfeta
, because the fill CAN access all the data defined in the outer layers, like the{% with %}
tag.Given this template:
class RootComp(Component):\n template = \"\"\"\n {% with cheese=\"feta\" %}\n {% component 'my_comp' %}\n {{ my_var }} # my_var\n {{ cheese }} # cheese\n {% endcomponent %}\n {% endwith %}\n \"\"\"\n\n def get_context_data(self):\n return { \"my_var\": 123 }\n
Then if
get_context_data()
of the component\"my_comp\"
returns following data:{ \"my_var\": 456 }\n
Then the template will be rendered as:
123 # my_var\n # cheese\n
Because variables
\"my_var\"
and\"cheese\"
are searched only insideRootComponent.get_context_data()
. But since\"cheese\"
is not defined there, it's empty.Info
Notice that the variables defined with the
"},{"location":"concepts/fundamentals/components_as_views/","title":"Components as views","text":"{% with %}
tag are ignored inside the{% fill %}
tag with the\"isolated\"
mode.New in version 0.34
Note: Since 0.92, Component no longer subclasses View. To configure the View class, set the nested
Component.View
classComponents can now be used as views:
-
Components define the
Component.as_view()
class method that can be used the same asView.as_view()
. -
By default, you can define GET, POST or other HTTP handlers directly on the Component, same as you do with View. For example, you can override
get
andpost
to handle GET and POST requests, respectively. -
In addition,
Component
now has arender_to_response
method that renders the component template based on the provided context and slots' data and returns anHttpResponse
object.
Here's an example of a calendar component defined as a view:
# In a file called [project root]/components/calendar.py\nfrom django_components import Component, ComponentView, register\n\n@register(\"calendar\")\nclass Calendar(Component):\n\n template = \"\"\"\n <div class=\"calendar-component\">\n <div class=\"header\">\n {% slot \"header\" / %}\n </div>\n <div class=\"body\">\n Today's date is <span>{{ date }}</span>\n </div>\n </div>\n \"\"\"\n\n # Handle GET requests\n def get(self, request, *args, **kwargs):\n context = {\n \"date\": request.GET.get(\"date\", \"2020-06-06\"),\n }\n slots = {\n \"header\": \"Calendar header\",\n }\n # Return HttpResponse with the rendered content\n return self.render_to_response(\n context=context,\n slots=slots,\n )\n
Then, to use this component as a view, you should create a
urls.py
file in your components directory, and add a path to the component's view:# In a file called [project root]/components/urls.py\nfrom django.urls import path\nfrom components.calendar.calendar import Calendar\n\nurlpatterns = [\n path(\"calendar/\", Calendar.as_view()),\n]\n
Component.as_view()
is a shorthand for callingView.as_view()
and passing the component instance as one of the arguments.Remember to add
__init__.py
to your components directory, so that Django can find theurls.py
file.Finally, include the component's urls in your project's
urls.py
file:# In a file called [project root]/urls.py\nfrom django.urls import include, path\n\nurlpatterns = [\n path(\"components/\", include(\"components.urls\")),\n]\n
Note: Slots content are automatically escaped by default to prevent XSS attacks. To disable escaping, set
escape_slots_content=False
in therender_to_response
method. If you do so, you should make sure that any content you pass to the slots is safe, especially if it comes from user input.If you're planning on passing an HTML string, check Django's use of
"},{"location":"concepts/fundamentals/components_as_views/#modifying-the-view-class","title":"Modifying the View class","text":"format_html
andmark_safe
.The View class that handles the requests is defined on
Component.View
.When you define a GET or POST handlers on the
Component
class, like so:class MyComponent(Component):\n def get(self, request, *args, **kwargs):\n return self.render_to_response(\n context={\n \"date\": request.GET.get(\"date\", \"2020-06-06\"),\n },\n )\n\n def post(self, request, *args, **kwargs) -> HttpResponse:\n variable = request.POST.get(\"variable\")\n return self.render_to_response(\n kwargs={\"variable\": variable}\n )\n
Then the request is still handled by
Component.View.get()
orComponent.View.post()
methods. However, by default,Component.View.get()
points toComponent.get()
, and so on.class ComponentView(View):\n component: Component = None\n ...\n\n def get(self, request, *args, **kwargs):\n return self.component.get(request, *args, **kwargs)\n\n def post(self, request, *args, **kwargs):\n return self.component.post(request, *args, **kwargs)\n\n ...\n
If you want to define your own
View
class, you need to:- Set the class as
Component.View
- Subclass from
ComponentView
, so the View instance has access to the component instance.
In the example below, we added extra logic into
View.setup()
.Note that the POST handler is still defined at the top. This is because
View
subclassesComponentView
, which defines thepost()
method that callsComponent.post()
.If you were to overwrite the
View.post()
method, thenComponent.post()
would be ignored.
"},{"location":"concepts/fundamentals/components_in_python/","title":"Components in Python","text":"from django_components import Component, ComponentView\n\nclass MyComponent(Component):\n\n def post(self, request, *args, **kwargs) -> HttpResponse:\n variable = request.POST.get(\"variable\")\n return self.component.render_to_response(\n kwargs={\"variable\": variable}\n )\n\n class View(ComponentView):\n def setup(self, request, *args, **kwargs):\n super(request, *args, **kwargs)\n\n do_something_extra(request, *args, **kwargs)\n
New in version 0.81
Components can be rendered outside of Django templates, calling them as regular functions (\"React-style\").
The component class defines
render
andrender_to_response
class methods. These methods accept positional args, kwargs, and slots, offering the same flexibility as the{% component %}
tag:class SimpleComponent(Component):\n template = \"\"\"\n {% load component_tags %}\n hello: {{ hello }}\n foo: {{ foo }}\n kwargs: {{ kwargs|safe }}\n slot_first: {% slot \"first\" required / %}\n \"\"\"\n\n def get_context_data(self, arg1, arg2, **kwargs):\n return {\n \"hello\": arg1,\n \"foo\": arg2,\n \"kwargs\": kwargs,\n }\n\nrendered = SimpleComponent.render(\n args=[\"world\", \"bar\"],\n kwargs={\"kw1\": \"test\", \"kw2\": \"ooo\"},\n slots={\"first\": \"FIRST_SLOT\"},\n context={\"from_context\": 98},\n)\n
Renders:
"},{"location":"concepts/fundamentals/components_in_python/#inputs-of-render-and-render_to_response","title":"Inputs ofhello: world\nfoo: bar\nkwargs: {'kw1': 'test', 'kw2': 'ooo'}\nslot_first: FIRST_SLOT\n
render
andrender_to_response
","text":"Both
render
andrender_to_response
accept the same input:Component.render(\n context: Mapping | django.template.Context | None = None,\n args: List[Any] | None = None,\n kwargs: Dict[str, Any] | None = None,\n slots: Dict[str, str | SafeString | SlotFunc] | None = None,\n escape_slots_content: bool = True\n) -> str:\n
-
args
- Positional args for the component. This is the same as calling the component as{% component \"my_comp\" arg1 arg2 ... %}
-
kwargs
- Keyword args for the component. This is the same as calling the component as{% component \"my_comp\" key1=val1 key2=val2 ... %}
-
slots
- Component slot fills. This is the same as pasing{% fill %}
tags to the component. Accepts a dictionary of{ slot_name: slot_content }
whereslot_content
can be a string orSlotFunc
. -
escape_slots_content
- Whether the content fromslots
should be escaped.True
by default to prevent XSS attacks. If you disable escaping, you should make sure that any content you pass to the slots is safe, especially if it comes from user input. -
context
- A context (dictionary or Django's Context) within which the component is rendered. The keys on the context can be accessed from within the template. -
NOTE: In \"isolated\" mode, context is NOT accessible, and data MUST be passed via component's args and kwargs.
-
request
- A Django request object. This is used to enable Django templatecontext_processors
to run, allowing for template tags like{% csrf_token %}
and variables like{{ debug }}
. - Similar behavior can be achieved with provide / inject.
- This is used internally to convert
context
to a RequestContext. It does nothing ifcontext
is already aContext
instance.
SlotFunc
","text":"When rendering components with slots in
render
orrender_to_response
, you can pass either a string or a function.The function has following signature:
def render_func(\n context: Context,\n data: Dict[str, Any],\n slot_ref: SlotRef,\n) -> str | SafeString:\n return nodelist.render(ctx)\n
context
- Django's Context available to the Slot Node.data
- Data passed to the{% slot %}
tag. See Scoped Slots.slot_ref
- The default slot content. See Accessing original content of slots.- NOTE: The slot is lazily evaluated. To render the slot, convert it to string with
str(slot_ref)
.
Example:
"},{"location":"concepts/fundamentals/components_in_python/#response-class-of-render_to_response","title":"Response class ofdef footer_slot(ctx, data, slot_ref):\n return f\"\"\"\n SLOT_DATA: {data['abc']}\n ORIGINAL: {slot_ref}\n \"\"\"\n\nMyComponent.render_to_response(\n slots={\n \"footer\": footer_slot,\n },\n)\n
render_to_response
","text":"While
render
method returns a plain string,render_to_response
wraps the rendered content in a \"Response\" class. By default, this isdjango.http.HttpResponse
.If you want to use a different Response class in
render_to_response
, set theComponent.response_class
attribute:
"},{"location":"concepts/fundamentals/defining_js_css_html_files/","title":"Defining HTML / JS / CSS files","text":"class MyResponse(HttpResponse):\n def __init__(self, *args, **kwargs) -> None:\n super().__init__(*args, **kwargs)\n # Configure response\n self.headers = ...\n self.status = ...\n\nclass SimpleComponent(Component):\n response_class = MyResponse\n template: types.django_html = \"HELLO\"\n\nresponse = SimpleComponent.render_to_response()\nassert isinstance(response, MyResponse)\n
As you could have seen in the tutorial, there's multiple ways how you can associate HTML / JS / CSS with a component:
- You can set
Component.template
,Component.css
andComponent.js
to define the main HTML / CSS / JS for a component as inlined code. - You can set
Component.template_file
,Component.css_file
andComponent.js_file
to define the main HTML / CSS / JS for a component in separate files. - You can link additional CSS / JS files using
Component.Media.js
andComponent.Media.css
.
Warning
You cannot use both inlined code and separate file for a single language type:
- You can only either set
Component.template
orComponent.template_file
- You can only either set
Component.css
orComponent.css_file
- You can only either set
Component.js
orComponent.js_file
However, you can freely mix these for different languages:
class MyTable(Component):\n template: types.django_html = \"\"\"\n <div class=\"welcome\">\n Hi there!\n </div>\n \"\"\"\n js_file = \"my_table.js\"\n css_file = \"my_table.css\"\n
Note
django-component's management of files is inspired by Django's
Media
class.To be familiar with how Django handles static files, we recommend reading also:
- How to manage static files (e.g. images, JavaScript, CSS)
As seen in the getting started example, to associate HTML / JS / CSS files with a component, you can set them as
[project root]/components/calendar/calendar.pyComponent.template_file
,Component.js_file
andComponent.css_file
respectively:from django_components import Component, register\n\n@register(\"calendar\")\nclass Calendar(Component):\n template_file = \"template.html\"\n css_file = \"style.css\"\n js_file = \"script.js\"\n
In the example above, we defined the files relative to the directory where the component file is defined.
Alternatively, you can specify the file paths relative to the directories set in
COMPONENTS.dirs
orCOMPONENTS.app_dirs
.If you specify the paths relative to component's directory, django-componenents does the conversion automatically for you.
Thus, assuming that
[project root]/components/calendar/calendar.pyCOMPONENTS.dirs
contains path[project root]/components
, the example above is the same as writing:from django_components import Component, register\n\n@register(\"calendar\")\nclass Calendar(Component):\n template_file = \"calendar/template.html\"\n css_file = \"calendar/style.css\"\n js_file = \"calendar/script.js\"\n
Important
File path resolution in-depth
At component class creation, django-components checks all file paths defined on the component (e.g.
Component.template_file
).For each file path, it checks if the file path is relative to the component's directory. And such file exists, the component's file path is re-written to be defined relative to a first matching directory in
COMPONENTS.dirs
orCOMPONENTS.app_dirs
.Example:
[root]/components/mytable/mytable.pyclass MyTable(Component):\n template_file = \"mytable.html\"\n
- Component
MyTable
is defined in file[root]/components/mytable/mytable.py
. - The component's directory is thus
[root]/components/mytable/
. - Because
MyTable.template_file
ismytable.html
, django-components tries to resolve it as[root]/components/mytable/mytable.html
. - django-components checks the filesystem. If there's no such file, nothing happens.
- If there IS such file, django-components tries to rewrite the path.
- django-components searches
COMPONENTS.dirs
andCOMPONENTS.app_dirs
for a first directory that contains[root]/components/mytable/mytable.html
. - It comes across
[root]/components/
, which DOES contain the path tomytable.html
. - Thus, it rewrites
template_file
frommytable.html
tomytable/mytable.html
.
NOTE: In case of ambiguity, the preference goes to resolving the files relative to the component's directory.
"},{"location":"concepts/fundamentals/defining_js_css_html_files/#defining-additional-js-and-css-files","title":"Defining additional JS and CSS files","text":"Each component can have only a single template, and single main JS and CSS. However, you can define additional JS or CSS using the nested
Component.Media
class.This
Media
class behaves similarly to Django's Media class:- Paths are generally handled as static file paths, and resolved URLs are rendered to HTML with
media_class.render_js()
ormedia_class.render_css()
. - A path that starts with
http
,https
, or/
is considered a URL, skipping the static file resolution. This path is still rendered to HTML withmedia_class.render_js()
ormedia_class.render_css()
. - A
SafeString
, or a function (with__html__
method) is considered an already-formatted HTML tag, skipping both static file resolution and rendering withmedia_class.render_js()
ormedia_class.render_css()
. - You can set
extend
to configure whether to inherit JS / CSS from parent components. See Controlling Media Inheritance.
However, there's a few differences from Django's Media class:
- Our Media class accepts various formats for the JS and CSS files: either a single file, a list, or (CSS-only) a dictonary (See
ComponentMediaInput
). - Individual JS / CSS files can be any of
str
,bytes
,Path
,SafeString
, or a function (SeeComponentMediaInputPath
).
"},{"location":"concepts/fundamentals/defining_js_css_html_files/#configuring-css-media-types","title":"Configuring CSS Media Types","text":"class MyTable(Component):\n class Media:\n js = [\n \"path/to/script.js\",\n \"https://unpkg.com/alpinejs@3.14.7/dist/cdn.min.js\", # AlpineJS\n ]\n css = {\n \"all\": [\n \"path/to/style.css\",\n \"https://unpkg.com/tailwindcss@^2/dist/tailwind.min.css\", # TailwindCSS\n ],\n \"print\": [\"path/to/style2.css\"],\n }\n
You can define which stylesheets will be associated with which CSS Media types. You do so by defining CSS files as a dictionary.
See the corresponding Django Documentation.
Again, you can set either a single file or a list of files per media type:
class MyComponent(Component):\n class Media:\n css = {\n \"all\": \"path/to/style1.css\",\n \"print\": [\"path/to/style2.css\", \"path/to/style3.css\"],\n }\n
Note
When you define CSS as a string or a list, the
all
media type is implied.So these two examples are the same:
class MyComponent(Component):\n class Media:\n css = \"path/to/style1.css\"\n
"},{"location":"concepts/fundamentals/defining_js_css_html_files/#supported-types-for-file-paths","title":"Supported types for file paths","text":"class MyComponent(Component):\n class Media:\n css = {\n \"all\": [\"path/to/style1.css\"],\n }\n
File paths can be any of:
str
bytes
PathLike
(__fspath__
method)SafeData
(__html__
method)Callable
that returns any of the above, evaluated at class creation (__new__
)
See
ComponentMediaInputPath
.
"},{"location":"concepts/fundamentals/defining_js_css_html_files/#paths-as-objects","title":"Paths as objects","text":"from pathlib import Path\n\nfrom django.utils.safestring import mark_safe\n\nclass SimpleComponent(Component):\n class Media:\n css = [\n mark_safe('<link href=\"/static/calendar/style1.css\" rel=\"stylesheet\" />'),\n Path(\"calendar/style1.css\"),\n \"calendar/style2.css\",\n b\"calendar/style3.css\",\n lambda: \"calendar/style4.css\",\n ]\n js = [\n mark_safe('<script src=\"/static/calendar/script1.js\"></script>'),\n Path(\"calendar/script1.js\"),\n \"calendar/script2.js\",\n b\"calendar/script3.js\",\n lambda: \"calendar/script4.js\",\n ]\n
In the example above, you can see that when we used Django's
mark_safe()
to mark a string as aSafeString
, we had to define the full<script>
/<link>
tag.This is an extension of Django's Paths as objects feature, where \"safe\" strings are taken as is, and accessed only at render time.
Because of that, the paths defined as \"safe\" strings are NEVER resolved, neither relative to component's directory, nor relative to
COMPONENTS.dirs
.\"Safe\" strings can be used to lazily resolve a path, or to customize the
<script>
or<link>
tag for individual paths:In the example below, we make use of \"safe\" strings to add
type=\"module\"
to the script tag that will fetchcalendar/script2.js
. In this case, we implemented a \"safe\" string by defining a__html__
method.
"},{"location":"concepts/fundamentals/defining_js_css_html_files/#customize-how-paths-are-rendered-into-html-tags","title":"Customize how paths are rendered into HTML tags","text":"class ModuleJsPath:\n def __init__(self, static_path: str) -> None:\n self.static_path = static_path\n\n def __html__(self):\n full_path = static(self.static_path)\n return format_html(\n f'<script type=\"module\" src=\"{full_path}\"></script>'\n )\n\n@register(\"calendar\")\nclass Calendar(Component):\n template_file = \"calendar/template.html\"\n\n def get_context_data(self, date):\n return {\n \"date\": date,\n }\n\n class Media:\n css = \"calendar/style1.css\"\n js = [\n # <script> tag constructed by Media class\n \"calendar/script1.js\",\n # Custom <script> tag\n ModuleJsPath(\"calendar/script2.js\"),\n ]\n
Sometimes you may need to change how all CSS
<link>
or JS<script>
tags are rendered for a given component. You can achieve this by providing your own subclass of Django'sMedia
class to component'smedia_class
attribute.Normally, the JS and CSS paths are passed to
Media
class, which decides how the paths are resolved and how the<link>
and<script>
tags are constructed.To change how the tags are constructed, you can override the
Media.render_js
andMedia.render_css
methods:
"},{"location":"concepts/fundamentals/defining_js_css_html_files/#accessing-components-html-js-css","title":"Accessing component's HTML / JS / CSS","text":"from django.forms.widgets import Media\nfrom django_components import Component, register\n\nclass MyMedia(Media):\n # Same as original Media.render_js, except\n # the `<script>` tag has also `type=\"module\"`\n def render_js(self):\n tags = []\n for path in self._js:\n if hasattr(path, \"__html__\"):\n tag = path.__html__()\n else:\n tag = format_html(\n '<script type=\"module\" src=\"{}\"></script>',\n self.absolute_path(path)\n )\n return tags\n\n@register(\"calendar\")\nclass Calendar(Component):\n template_file = \"calendar/template.html\"\n css_file = \"calendar/style.css\"\n js_file = \"calendar/script.js\"\n\n class Media:\n css = \"calendar/style1.css\"\n js = \"calendar/script2.js\"\n\n # Override the behavior of Media class\n media_class = MyMedia\n
Component's HTML / CSS / JS is resolved and loaded lazily.
This means that, when you specify any of
template_file
,js_file
,css_file
, orMedia.js/css
, these file paths will be resolved only once you either:-
Access any of the following attributes on the component:
media
,template
,template_file
,js
,js_file
,css
,css_file
-
Render the component.
Once the component's media files have been loaded once, they will remain in-memory on the Component class:
- HTML from
Component.template_file
will be available underComponent.template
- CSS from
Component.css_file
will be available underComponent.css
- JS from
Component.js_file
will be available underComponent.js
Thus, whether you define HTML via
Component.template_file
orComponent.template
, you can always access the HTML content underComponent.template
. And the same applies for JS and CSS.Example:
# When we create Calendar component, the files like `calendar/template.html`\n# are not yet loaded!\n@register(\"calendar\")\nclass Calendar(Component):\n template_file = \"calendar/template.html\"\n css_file = \"calendar/style.css\"\n js_file = \"calendar/script.js\"\n\n class Media:\n css = \"calendar/style1.css\"\n js = \"calendar/script2.js\"\n\n# It's only at this moment that django-components reads the files like `calendar/template.html`\nprint(Calendar.css)\n# Output:\n# .calendar {\n# width: 200px;\n# background: pink;\n# }\n
Warning
Do NOT modify HTML / CSS / JS after it has been loaded
django-components assumes that the component's media files like
js_file
orMedia.js/css
are static.If you need to dynamically change these media files, consider instead defining multiple Components.
Modifying these files AFTER the component has been loaded at best does nothing. However, this is an untested behavior, which may lead to unexpected errors.
"},{"location":"concepts/fundamentals/defining_js_css_html_files/#accessing-components-media-files","title":"Accessing component's Media files","text":"To access the files that you defined under
Component.Media
, useComponent.media
(lowercase). This is consistent behavior with Django's Media class.
"},{"location":"concepts/fundamentals/defining_js_css_html_files/#componentmedia-vs-componentmedia","title":"class MyComponent(Component):\n class Media:\n js = \"path/to/script.js\"\n css = \"path/to/style.css\"\n\nprint(MyComponent.media)\n# Output:\n# <script src=\"/static/path/to/script.js\"></script>\n# <link href=\"/static/path/to/style.css\" media=\"all\" rel=\"stylesheet\">\n
Component.Media
vsComponent.media
","text":"When working with component media files, there are a few important concepts to understand:
-
Component.Media
- Is the \"raw\" media definition, or the input, which holds only the component's own media definition
- This class is NOT instantiated, it merely holds the JS / CSS files.
-
Component.media
- Returns all resolved media files, including those inherited from parent components
- Is an instance of
Component.media_class
class ParentComponent(Component):\n class Media:\n js = [\"parent.js\"]\n\nclass ChildComponent(ParentComponent):\n class Media:\n js = [\"child.js\"]\n\n# Access only this component's media\nprint(ChildComponent.Media.js) # [\"child.js\"]\n\n# Access all inherited media\nprint(ChildComponent.media._js) # [\"parent.js\", \"child.js\"]\n
Note
You should not manually modify
Component.media
orComponent.Media
after the component has been resolved, as this may lead to unexpected behavior.If you want to modify the class that is instantiated for
"},{"location":"concepts/fundamentals/defining_js_css_html_files/#controlling-media-inheritance","title":"Controlling Media Inheritance","text":"Component.media
, you can configureComponent.media_class
(See example).By default, the media files are inherited from the parent component.
class ParentComponent(Component):\n class Media:\n js = [\"parent.js\"]\n\nclass MyComponent(ParentComponent):\n class Media:\n js = [\"script.js\"]\n\nprint(MyComponent.media._js) # [\"parent.js\", \"script.js\"]\n
You can set the component NOT to inherit from the parent component by setting the
extend
attribute toFalse
:class ParentComponent(Component):\n class Media:\n js = [\"parent.js\"]\n\nclass MyComponent(ParentComponent):\n class Media:\n extend = False # Don't inherit parent media\n js = [\"script.js\"]\n\nprint(MyComponent.media._js) # [\"script.js\"]\n
Alternatively, you can specify which components to inherit from. In such case, the media files are inherited ONLY from the specified components, and NOT from the original parent components:
class ParentComponent(Component):\n class Media:\n js = [\"parent.js\"]\n\nclass MyComponent(ParentComponent):\n class Media:\n # Only inherit from these, ignoring the files from the parent\n extend = [OtherComponent1, OtherComponent2]\n\n js = [\"script.js\"]\n\nprint(MyComponent.media._js) # [\"script.js\", \"other1.js\", \"other2.js\"]\n
Info
The
extend
behaves consistently with Django's Media class, with one exception:- When you set
extend
to a list, the list is expected to contain Component classes (or other classes that have a nestedMedia
class).
New in version 0.74:
You can use the
html_attrs
tag to render HTML attributes, given a dictionary of values.So if you have a template:
<div class=\"{{ classes }}\" data-id=\"{{ my_id }}\">\n</div>\n
You can simplify it with
html_attrs
tag:<div {% html_attrs attrs %}>\n</div>\n
where
attrs
is:attrs = {\n \"class\": classes,\n \"data-id\": my_id,\n}\n
This feature is inspired by
"},{"location":"concepts/fundamentals/html_attributes/#removing-atttributes","title":"Removing atttributes","text":"merge_attrs
tag of django-web-components and \"fallthrough attributes\" feature of Vue.Attributes that are set to
None
orFalse
are NOT rendered.So given this input:
attrs = {\n \"class\": \"text-green\",\n \"required\": False,\n \"data-id\": None,\n}\n
And template:
<div {% html_attrs attrs %}>\n</div>\n
Then this renders:
"},{"location":"concepts/fundamentals/html_attributes/#boolean-attributes","title":"Boolean attributes","text":"<div class=\"text-green\"></div>\n
In HTML, boolean attributes are usually rendered with no value. Consider the example below where the first button is disabled and the second is not:
<button disabled>Click me!</button> <button>Click me!</button>\n
HTML rendering with
html_attrs
tag orattributes_to_string
works the same way, wherekey=True
is rendered simply askey
, andkey=False
is not render at all.So given this input:
attrs = {\n \"disabled\": True,\n \"autofocus\": False,\n}\n
And template:
<div {% html_attrs attrs %}>\n</div>\n
Then this renders:
"},{"location":"concepts/fundamentals/html_attributes/#default-attributes","title":"Default attributes","text":"<div disabled></div>\n
Sometimes you may want to specify default values for attributes. You can pass a second argument (or kwarg
defaults
) to set the defaults.<div {% html_attrs attrs defaults %}>\n ...\n</div>\n
In the example above, if
attrs
contains e.g. theclass
key,html_attrs
will render:class=\"{{ attrs.class }}\"
Otherwise,
html_attrs
will render:
"},{"location":"concepts/fundamentals/html_attributes/#appending-attributes","title":"Appending attributes","text":"class=\"{{ defaults.class }}\"
For the
class
HTML attribute, it's common that we want to join multiple values, instead of overriding them. For example, if you're authoring a component, you may want to ensure that the component will ALWAYS have a specific class. Yet, you may want to allow users of your component to supply their own classes.We can achieve this by adding extra kwargs. These values will be appended, instead of overwriting the previous value.
So if we have a variable
attrs
:attrs = {\n \"class\": \"my-class pa-4\",\n}\n
And on
html_attrs
tag, we set the keyclass
:<div {% html_attrs attrs class=\"some-class\" %}>\n</div>\n
Then these will be merged and rendered as:
<div data-value=\"my-class pa-4 some-class\"></div>\n
To simplify merging of variables, you can supply the same key multiple times, and these will be all joined together:
{# my_var = \"class-from-var text-red\" #}\n<div {% html_attrs attrs class=\"some-class another-class\" class=my_var %}>\n</div>\n
Renders:
"},{"location":"concepts/fundamentals/html_attributes/#rules-for-html_attrs","title":"Rules for<div\n data-value=\"my-class pa-4 some-class another-class class-from-var text-red\"\n></div>\n
html_attrs
","text":"- Both
attrs
anddefaults
can be passed as positional args
{% html_attrs attrs defaults key=val %}
or as kwargs
{% html_attrs key=val defaults=defaults attrs=attrs %}
-
Both
attrs
anddefaults
are optional (can be omitted) -
Both
attrs
anddefaults
are dictionaries, and we can define them the same way we define dictionaries for thecomponent
tag. So either asattrs=attrs
orattrs:key=value
. -
All other kwargs are appended and can be repeated.
html_attrs
","text":"Assuming that:
class_from_var = \"from-var\"\n\nattrs = {\n \"class\": \"from-attrs\",\n \"type\": \"submit\",\n}\n\ndefaults = {\n \"class\": \"from-defaults\",\n \"role\": \"button\",\n}\n
Then:
- Empty tag
{% html_attr %}
renders (empty string):
- Only kwargs
{% html_attr class=\"some-class\" class=class_from_var data-id=\"123\" %}
renders:
class=\"some-class from-var\" data-id=\"123\"
- Only attrs
{% html_attr attrs %}
renders:
class=\"from-attrs\" type=\"submit\"
- Attrs as kwarg
{% html_attr attrs=attrs %}
renders:
class=\"from-attrs\" type=\"submit\"
- Only defaults (as kwarg)
{% html_attr defaults=defaults %}
renders:
class=\"from-defaults\" role=\"button\"
- Attrs using the
prefix:key=value
construct{% html_attr attrs:class=\"from-attrs\" attrs:type=\"submit\" %}
renders:
class=\"from-attrs\" type=\"submit\"
- Defaults using the
prefix:key=value
construct{% html_attr defaults:class=\"from-defaults\" %}
renders:
class=\"from-defaults\" role=\"button\"
- All together (1) - attrs and defaults as positional args:
{% html_attrs attrs defaults class=\"added_class\" class=class_from_var data-id=123 %}
renders:
class=\"from-attrs added_class from-var\" type=\"submit\" role=\"button\" data-id=123
- All together (2) - attrs and defaults as kwargs args:
{% html_attrs class=\"added_class\" class=class_from_var data-id=123 attrs=attrs defaults=defaults %}
renders:
class=\"from-attrs added_class from-var\" type=\"submit\" role=\"button\" data-id=123
- All together (3) - mixed:
{% html_attrs attrs defaults:class=\"default-class\" class=\"added_class\" class=class_from_var data-id=123 %}
renders:
"},{"location":"concepts/fundamentals/html_attributes/#full-example-for-html_attrs","title":"Full example forclass=\"from-attrs added_class from-var\" type=\"submit\" data-id=123
html_attrs
","text":"@register(\"my_comp\")\nclass MyComp(Component):\n template: t.django_html = \"\"\"\n <div\n {% html_attrs attrs\n defaults:class=\"pa-4 text-red\"\n class=\"my-comp-date\"\n class=class_from_var\n data-id=\"123\"\n %}\n >\n Today's date is <span>{{ date }}</span>\n </div>\n \"\"\"\n\n def get_context_data(self, date: Date, attrs: dict):\n return {\n \"date\": date,\n \"attrs\": attrs,\n \"class_from_var\": \"extra-class\"\n }\n\n@register(\"parent\")\nclass Parent(Component):\n template: t.django_html = \"\"\"\n {% component \"my_comp\"\n date=date\n attrs:class=\"pa-0 border-solid border-red\"\n attrs:data-json=json_data\n attrs:@click=\"(e) => onClick(e, 'from_parent')\"\n / %}\n \"\"\"\n\n def get_context_data(self, date: Date):\n return {\n \"date\": datetime.now(),\n \"json_data\": json.dumps({\"value\": 456})\n }\n
Note: For readability, we've split the tags across multiple lines.
Inside
MyComp
, we defined a default attributedefaults:class=\"pa-4 text-red\"
So if
attrs
includes keyclass
, the default above will be ignored.MyComp
also definesclass
key twice. It means that whether theclass
attribute is taken fromattrs
ordefaults
, the twoclass
values will be appended to it.So by default,
MyComp
renders:<div class=\"pa-4 text-red my-comp-date extra-class\" data-id=\"123\">...</div>\n
Next, let's consider what will be rendered when we call
MyComp
fromParent
component.MyComp
accepts aattrs
dictionary, that is passed tohtml_attrs
, so the contents of that dictionary are rendered as the HTML attributes.In
Parent
, we make use of passing dictionary key-value pairs as kwargs to define individual attributes as if they were regular kwargs.So all kwargs that start with
attrs:
will be collected into anattrs
dict.attrs:class=\"pa-0 border-solid border-red\"\n attrs:data-json=json_data\n attrs:@click=\"(e) => onClick(e, 'from_parent')\"\n
And
get_context_data
ofMyComp
will receiveattrs
input with following keys:attrs = {\n \"class\": \"pa-0 border-solid\",\n \"data-json\": '{\"value\": 456}',\n \"@click\": \"(e) => onClick(e, 'from_parent')\",\n}\n
attrs[\"class\"]
overrides the default value forclass
, whereas other keys will be merged.So in the end
MyComp
will render:
"},{"location":"concepts/fundamentals/html_attributes/#rendering-html-attributes-outside-of-templates","title":"Rendering HTML attributes outside of templates","text":"<div\n class=\"pa-0 border-solid my-comp-date extra-class\"\n data-id=\"123\"\n data-json='{\"value\": 456}'\n @click=\"(e) => onClick(e, 'from_parent')\"\n>\n ...\n</div>\n
If you need to use serialize HTML attributes outside of Django template and the
html_attrs
tag, you can useattributes_to_string
:
"},{"location":"concepts/fundamentals/single_file_components/","title":"Single-file components","text":"from django_components.attributes import attributes_to_string\n\nattrs = {\n \"class\": \"my-class text-red pa-4\",\n \"data-id\": 123,\n \"required\": True,\n \"disabled\": False,\n \"ignored-attr\": None,\n}\n\nattributes_to_string(attrs)\n# 'class=\"my-class text-red pa-4\" data-id=\"123\" required'\n
Components can be defined in a single file, which is useful for small components. To do this, you can use the
template
,js
, andcss
class attributes instead of thetemplate_file
,js_file
, andcss_file
.For example, here's the calendar component from the Getting started tutorial, defined in a single file:
[project root]/components/calendar.pyfrom django_components import Component, register, types\n\n@register(\"calendar\")\nclass Calendar(Component):\n def get_context_data(self, date):\n return {\n \"date\": date,\n }\n\n template: types.django_html = \"\"\"\n <div class=\"calendar\">\n Today's date is <span>{{ date }}</span>\n </div>\n \"\"\"\n\n css: types.css = \"\"\"\n .calendar {\n width: 200px;\n background: pink;\n }\n .calendar span {\n font-weight: bold;\n }\n \"\"\"\n\n js: types.js = \"\"\"\n (function(){\n if (document.querySelector(\".calendar\")) {\n document.querySelector(\".calendar\").onclick = () => {\n alert(\"Clicked calendar!\");\n };\n }\n })()\n \"\"\"\n
This makes it easy to create small components without having to create a separate template, CSS, and JS file.
To add syntax highlighting to these snippets, head over to Syntax highlighting.
"},{"location":"concepts/fundamentals/slots/","title":"Slots","text":"New in version 0.26:
- The
slot
tag now serves only to declare new slots inside the component template. - To override the content of a declared slot, use the newly introduced
fill
tag instead. - Whereas unfilled slots used to raise a warning, filling a slot is now optional by default.
- To indicate that a slot must be filled, the new
required
option should be added at the end of theslot
tag.
Components support something called 'slots'. When a component is used inside another template, slots allow the parent template to override specific parts of the child component by passing in different content. This mechanism makes components more reusable and composable. This behavior is similar to slots in Vue.
In the example below we introduce two block tags that work hand in hand to make this work. These are...
{% slot <name> %}
/{% endslot %}
: Declares a new slot in the component template.{% fill <name> %}
/{% endfill %}
: (Used inside a{% component %}
tag pair.) Fills a declared slot with the specified content.
Let's update our calendar component to support more customization. We'll add
slot
tag pairs to its template, template.html.<div class=\"calendar-component\">\n <div class=\"header\">\n {% slot \"header\" %}Calendar header{% endslot %}\n </div>\n <div class=\"body\">\n {% slot \"body\" %}Today's date is <span>{{ date }}</span>{% endslot %}\n </div>\n</div>\n
When using the component, you specify which slots you want to fill and where you want to use the defaults from the template. It looks like this:
{% component \"calendar\" date=\"2020-06-06\" %}\n {% fill \"body\" %}\n Can you believe it's already <span>{{ date }}</span>??\n {% endfill %}\n{% endcomponent %}\n
Since the 'header' fill is unspecified, it's taken from the base template. If you put this in a template, and pass in
date=2020-06-06
, this is what gets rendered:
"},{"location":"concepts/fundamentals/slots/#named-slots","title":"Named slots","text":"<div class=\"calendar-component\">\n <div class=\"header\">\n Calendar header\n </div>\n <div class=\"body\">\n Can you believe it's already <span>2020-06-06</span>??\n </div>\n</div>\n
As seen in the previouse section, you can use
{% fill slot_name %}
to insert content into a specific slot.You can define fills for multiple slot simply by defining them all within the
{% component %} {% endcomponent %}
tags:{% component \"calendar\" date=\"2020-06-06\" %}\n {% fill \"header\" %}\n Hi this is header!\n {% endfill %}\n {% fill \"body\" %}\n Can you believe it's already <span>{{ date }}</span>??\n {% endfill %}\n{% endcomponent %}\n
You can also use
{% for %}
,{% with %}
, or other non-component tags (even{% include %}
) to construct the{% fill %}
tags, as long as these other tags do not leave any text behind!
"},{"location":"concepts/fundamentals/slots/#default-slot","title":"Default slot","text":"{% component \"table\" %}\n {% for slot_name in slots %}\n {% fill name=slot_name %}\n {{ slot_name }}\n {% endfill %}\n {% endfor %}\n\n {% with slot_name=\"abc\" %}\n {% fill name=slot_name %}\n {{ slot_name }}\n {% endfill %}\n {% endwith %}\n{% endcomponent %}\n
Added in version 0.28
As you can see, component slots lets you write reusable containers that you fill in when you use a component. This makes for highly reusable components that can be used in different circumstances.
It can become tedious to use
fill
tags everywhere, especially when you're using a component that declares only one slot. To make things easier,slot
tags can be marked with an optional keyword:default
.When added to the tag (as shown below), this option lets you pass filling content directly in the body of a
component
tag pair \u2013 without using afill
tag. Choose carefully, though: a component template may contain at most one slot that is marked asdefault
. Thedefault
option can be combined with other slot options, e.g.required
.Here's the same example as before, except with default slots and implicit filling.
The template:
<div class=\"calendar-component\">\n <div class=\"header\">\n {% slot \"header\" %}Calendar header{% endslot %}\n </div>\n <div class=\"body\">\n {% slot \"body\" default %}Today's date is <span>{{ date }}</span>{% endslot %}\n </div>\n</div>\n
Including the component (notice how the
fill
tag is omitted):{% component \"calendar\" date=\"2020-06-06\" %}\n Can you believe it's already <span>{{ date }}</span>??\n{% endcomponent %}\n
The rendered result (exactly the same as before):
<div class=\"calendar-component\">\n <div class=\"header\">Calendar header</div>\n <div class=\"body\">Can you believe it's already <span>2020-06-06</span>??</div>\n</div>\n
You may be tempted to combine implicit fills with explicit
fill
tags. This will not work. The following component template will raise an error when rendered.{# DON'T DO THIS #}\n{% component \"calendar\" date=\"2020-06-06\" %}\n {% fill \"header\" %}Totally new header!{% endfill %}\n Can you believe it's already <span>{{ date }}</span>??\n{% endcomponent %}\n
Instead, you can use a named fill with name
default
to target the default fill:{# THIS WORKS #}\n{% component \"calendar\" date=\"2020-06-06\" %}\n {% fill \"header\" %}Totally new header!{% endfill %}\n {% fill \"default\" %}\n Can you believe it's already <span>{{ date }}</span>??\n {% endfill %}\n{% endcomponent %}\n
NOTE: If you doubly-fill a slot, that is, that both
"},{"location":"concepts/fundamentals/slots/#accessing-default-slot-in-python","title":"Accessing default slot in Python","text":"{% fill \"default\" %}
and{% fill \"header\" %}
would point to the same slot, this will raise an error when rendered.Since the default slot is stored under the slot name
default
, you can access the default slot like so:
"},{"location":"concepts/fundamentals/slots/#render-fill-in-multiple-places","title":"Render fill in multiple places","text":"class MyTable(Component):\n def get_context_data(self, *args, **kwargs):\n default_slot = self.input.slots[\"default\"]\n return {\n \"default_slot\": default_slot,\n }\n
Added in version 0.70
You can render the same content in multiple places by defining multiple slots with identical names:
<div class=\"calendar-component\">\n <div class=\"header\">\n {% slot \"image\" %}Image here{% endslot %}\n </div>\n <div class=\"body\">\n {% slot \"image\" %}Image here{% endslot %}\n </div>\n</div>\n
So if used like:
{% component \"calendar\" date=\"2020-06-06\" %}\n {% fill \"image\" %}\n <img src=\"...\" />\n {% endfill %}\n{% endcomponent %}\n
This renders:
"},{"location":"concepts/fundamentals/slots/#default-and-required-slots","title":"Default and required slots","text":"<div class=\"calendar-component\">\n <div class=\"header\">\n <img src=\"...\" />\n </div>\n <div class=\"body\">\n <img src=\"...\" />\n </div>\n</div>\n
If you use a slot multiple times, you can still mark the slot as
default
orrequired
. For that, you must mark each slot individually, e.g.:<div class=\"calendar-component\">\n <div class=\"header\">\n {% slot \"image\" default required %}Image here{% endslot %}\n </div>\n <div class=\"body\">\n {% slot \"image\" default required %}Image here{% endslot %}\n </div>\n</div>\n
Which you can then use as regular default slot:
{% component \"calendar\" date=\"2020-06-06\" %}\n <img src=\"...\" />\n{% endcomponent %}\n
Since each slot is tagged individually, you can have multiple slots with the same name but different conditions.
E.g. in this example, we have a component that renders a user avatar - a small circular image with a profile picture or name initials.
If the component is given
image_src
orname_initials
variables, theimage
slot is optional. But if neither of those are provided, you MUST fill theimage
slot.
"},{"location":"concepts/fundamentals/slots/#accessing-original-content-of-slots","title":"Accessing original content of slots","text":"<div class=\"avatar\">\n {% if image_src %}\n {% slot \"image\" default %}\n <img src=\"{{ image_src }}\" />\n {% endslot %}\n {% elif name_initials %}\n {% slot \"image\" default %}\n <div style=\"\n border-radius: 25px;\n width: 50px;\n height: 50px;\n background: blue;\n \">\n {{ name_initials }}\n </div>\n {% endslot %}\n {% else %}\n {% slot \"image\" default required / %}\n {% endif %}\n</div>\n
Added in version 0.26
NOTE: In version 0.77, the syntax was changed from
{% fill \"my_slot\" as \"alias\" %} {{ alias.default }}\n
to
{% fill \"my_slot\" default=\"slot_default\" %} {{ slot_default }}\n
Sometimes you may want to keep the original slot, but only wrap or prepend/append content to it. To do so, you can access the default slot via the
default
kwarg.Similarly to the
data
attribute, you specify the variable name through which the default slot will be made available.For instance, let's say you're filling a slot called 'body'. To render the original slot, assign it to a variable using the
'default'
keyword. You then render this variable to insert the default content:{% component \"calendar\" date=\"2020-06-06\" %}\n {% fill \"body\" default=\"body_default\" %}\n {{ body_default }}. Have a great day!\n {% endfill %}\n{% endcomponent %}\n
This produces:
<div class=\"calendar-component\">\n <div class=\"header\">\n Calendar header\n </div>\n <div class=\"body\">\n Today's date is <span>2020-06-06</span>. Have a great day!\n </div>\n</div>\n
To access the original content of a default slot, set the name to
default
:
"},{"location":"concepts/fundamentals/slots/#conditional-slots","title":"Conditional slots","text":"{% component \"calendar\" date=\"2020-06-06\" %}\n {% fill \"default\" default=\"slot_default\" %}\n {{ slot_default }}. Have a great day!\n {% endfill %}\n{% endcomponent %}\n
Added in version 0.26.
NOTE: In version 0.70,
{% if_filled %}
tags were replaced with{{ component_vars.is_filled }}
variables. If your slot name contained special characters, see the section Accessingis_filled
of slot names with special characters.In certain circumstances, you may want the behavior of slot filling to depend on whether or not a particular slot is filled.
For example, suppose we have the following component template:
<div class=\"frontmatter-component\">\n <div class=\"title\">\n {% slot \"title\" %}Title{% endslot %}\n </div>\n <div class=\"subtitle\">\n {% slot \"subtitle\" %}{# Optional subtitle #}{% endslot %}\n </div>\n</div>\n
By default the slot named 'subtitle' is empty. Yet when the component is used without explicit fills, the div containing the slot is still rendered, as shown below:
<div class=\"frontmatter-component\">\n <div class=\"title\">Title</div>\n <div class=\"subtitle\"></div>\n</div>\n
This may not be what you want. What if instead the outer 'subtitle' div should only be included when the inner slot is in fact filled?
The answer is to use the
{{ component_vars.is_filled.<name> }}
variable. You can use this together with Django's{% if/elif/else/endif %}
tags to define a block whose contents will be rendered only if the component slot with the corresponding 'name' is filled.This is what our example looks like with
component_vars.is_filled
.<div class=\"frontmatter-component\">\n <div class=\"title\">\n {% slot \"title\" %}Title{% endslot %}\n </div>\n {% if component_vars.is_filled.subtitle %}\n <div class=\"subtitle\">\n {% slot \"subtitle\" %}{# Optional subtitle #}{% endslot %}\n </div>\n {% endif %}\n</div>\n
Here's our example with more complex branching.
<div class=\"frontmatter-component\">\n <div class=\"title\">\n {% slot \"title\" %}Title{% endslot %}\n </div>\n {% if component_vars.is_filled.subtitle %}\n <div class=\"subtitle\">\n {% slot \"subtitle\" %}{# Optional subtitle #}{% endslot %}\n </div>\n {% elif component_vars.is_filled.title %}\n ...\n {% elif component_vars.is_filled.<name> %}\n ...\n {% endif %}\n</div>\n
Sometimes you're not interested in whether a slot is filled, but rather that it isn't. To negate the meaning of
component_vars.is_filled
, simply treat it as boolean and negate it withnot
:
"},{"location":"concepts/fundamentals/slots/#accessing-is_filled-of-slot-names-with-special-characters","title":"Accessing{% if not component_vars.is_filled.subtitle %}\n<div class=\"subtitle\">\n {% slot \"subtitle\" / %}\n</div>\n{% endif %}\n
is_filled
of slot names with special characters","text":"To be able to access a slot name via
component_vars.is_filled
, the slot name needs to be composed of only alphanumeric characters and underscores (e.g.this__isvalid_123
).However, you can still define slots with other special characters. In such case, the slot name in
component_vars.is_filled
is modified to replace all invalid characters into_
.So a slot named
\"my super-slot :)\"
will be available ascomponent_vars.is_filled.my_super_slot___
.Same applies when you are accessing
is_filled
from within the Python, e.g.:
"},{"location":"concepts/fundamentals/slots/#conditional-fills","title":"Conditional fills","text":"class MyTable(Component):\n def on_render_before(self, context, template) -> None:\n # \u2705 Works\n if self.is_filled[\"my_super_slot___\"]:\n # Do something\n\n # \u274c Does not work\n if self.is_filled[\"my super-slot :)\"]:\n # Do something\n
Similarly, you can use
{% if %}
and{% for %}
when defining the{% fill %}
tags, to conditionally fill the slots when using the componnet:In the example below, the
{% fill \"footer\" %}
fill is used only if the condition is true. If falsy, the fill is ignored, and so themy_table
component will use its default content for thefooter
slot.{% component \"my_table\" %}\n {% if editable %}\n {% fill \"footer\" %}\n <input name=\"name\" />\n {% endfill %}\n {% endif %}\n{% endcomponent %}\n
You can even combine
{% if %}
and{% for %}
:
"},{"location":"concepts/fundamentals/slots/#scoped-slots","title":"Scoped slots","text":"{% component \"my_table\" %}\n {% for header in headers %}\n {% if header != \"hyperlink\" %}\n {# Generate fill name like `header.my_column` #}\n {% fill name=\"header.\"|add:header\" %}\n <b>{{ header }}</b>\n {% endfill %}\n {% endif %}\n {% endfor %}\n{% endcomponent %}\n
Added in version 0.76:
Consider a component with slot(s). This component may do some processing on the inputs, and then use the processed variable in the slot's default template:
@register(\"my_comp\")\nclass MyComp(Component):\n template = \"\"\"\n <div>\n {% slot \"content\" default %}\n input: {{ input }}\n {% endslot %}\n </div>\n \"\"\"\n\n def get_context_data(self, input):\n processed_input = do_something(input)\n return {\"input\": processed_input}\n
You may want to design a component so that users of your component can still access the
input
variable, so they don't have to recompute it.This behavior is called \"scoped slots\". This is inspired by Vue scoped slots and scoped slots of django-web-components.
Using scoped slots consists of two steps:
- Passing data to
slot
tag - Accessing data in
fill
tag
To pass the data to the
slot
tag, simply pass them as keyword attributes (key=value
):
"},{"location":"concepts/fundamentals/slots/#accessing-slot-data-in-fill","title":"Accessing slot data in fill","text":"@register(\"my_comp\")\nclass MyComp(Component):\n template = \"\"\"\n <div>\n {% slot \"content\" default input=input %}\n input: {{ input }}\n {% endslot %}\n </div>\n \"\"\"\n\n def get_context_data(self, input):\n processed_input = do_something(input)\n return {\n \"input\": processed_input,\n }\n
Next, we head over to where we define a fill for this slot. Here, to access the slot data we set the
data
attribute to the name of the variable through which we want to access the slot data. In the example below, we set it todata
:{% component \"my_comp\" %}\n {% fill \"content\" data=\"slot_data\" %}\n {{ slot_data.input }}\n {% endfill %}\n{% endcomponent %}\n
To access slot data on a default slot, you have to explictly define the
{% fill %}
tags.So this works:
{% component \"my_comp\" %}\n {% fill \"content\" data=\"slot_data\" %}\n {{ slot_data.input }}\n {% endfill %}\n{% endcomponent %}\n
While this does not:
{% component \"my_comp\" data=\"data\" %}\n {{ data.input }}\n{% endcomponent %}\n
Note: You cannot set the
data
attribute anddefault
attribute) to the same name. This raises an error:
"},{"location":"concepts/fundamentals/slots/#slot-data-of-default-slots","title":"Slot data of default slots","text":"{% component \"my_comp\" %}\n {% fill \"content\" data=\"slot_var\" default=\"slot_var\" %}\n {{ slot_var.input }}\n {% endfill %}\n{% endcomponent %}\n
To access data of a default slot, you can specify
{% fill name=\"default\" %}
:
"},{"location":"concepts/fundamentals/slots/#dynamic-slots-and-fills","title":"Dynamic slots and fills","text":"{% component \"my_comp\" %}\n {% fill \"default\" data=\"slot_data\" %}\n {{ slot_data.input }}\n {% endfill %}\n{% endcomponent %}\n
Until now, we were declaring slot and fill names statically, as a string literal, e.g.
{% slot \"content\" / %}\n
However, sometimes you may want to generate slots based on the given input. One example of this is a table component like that of Vuetify, which creates a header and an item slots for each user-defined column.
In django_components you can achieve the same, simply by using a variable (or a template expression) instead of a string literal:
<table>\n <tr>\n {% for header in headers %}\n <th>\n {% slot \"header-{{ header.key }}\" value=header.title %}\n {{ header.title }}\n {% endslot %}\n </th>\n {% endfor %}\n </tr>\n</table>\n
When using the component, you can either set the fill explicitly:
{% component \"table\" headers=headers items=items %}\n {% fill \"header-name\" data=\"data\" %}\n <b>{{ data.value }}</b>\n {% endfill %}\n{% endcomponent %}\n
Or also use a variable:
{% component \"table\" headers=headers items=items %}\n {# Make only the active column bold #}\n {% fill \"header-{{ active_header_name }}\" data=\"data\" %}\n <b>{{ data.value }}</b>\n {% endfill %}\n{% endcomponent %}\n
NOTE: It's better to use static slot names whenever possible for clarity. The dynamic slot names should be reserved for advanced use only.
Lastly, in rare cases, you can also pass the slot name via the spread operator. This is possible, because the slot name argument is actually a shortcut for a
name
keyword argument.So this:
{% slot \"content\" / %}\n
is the same as:
{% slot name=\"content\" / %}\n
So it's possible to define a
name
key on a dictionary, and then spread that onto the slot tag:
"},{"location":"concepts/fundamentals/slots/#pass-through-all-the-slots","title":"Pass through all the slots","text":"{# slot_props = {\"name\": \"content\"} #}\n{% slot ...slot_props / %}\n
You can dynamically pass all slots to a child component. This is similar to passing all slots in Vue:
"},{"location":"concepts/fundamentals/subclassing_components/","title":"Subclassing components","text":"class MyTable(Component):\n def get_context_data(self, *args, **kwargs):\n return {\n \"slots\": self.input.slots,\n }\n\n template: \"\"\"\n <div>\n {% component \"child\" %}\n {% for slot_name in slots %}\n {% fill name=slot_name data=\"data\" %}\n {% slot name=slot_name ...data / %}\n {% endfill %}\n {% endfor %}\n {% endcomponent %}\n </div>\n \"\"\"\n
In larger projects, you might need to write multiple components with similar behavior. In such cases, you can extract shared behavior into a standalone component class to keep things DRY.
When subclassing a component, there's a couple of things to keep in mind:
"},{"location":"concepts/fundamentals/subclassing_components/#template-js-and-css-inheritance","title":"Template, JS, and CSS Inheritance","text":"When it comes to the pairs:
Component.template
/Component.template_file
Component.js
/Component.js_file
Component.css
/Component.css_file
inheritance follows these rules:
- If a child component class defines either member of a pair (e.g., either
template
ortemplate_file
), it takes precedence and the parent's definition is ignored completely. - For example, if a child component defines
template_file
, the parent'stemplate
ortemplate_file
will be ignored. - This applies independently to each pair - you can inherit the JS while overriding the template, for instance.
For example:
"},{"location":"concepts/fundamentals/subclassing_components/#media-class-inheritance","title":"Media Class Inheritance","text":"class BaseCard(Component):\n template = \"\"\"\n <div class=\"card\">\n <div class=\"card-content\">{{ content }}</div>\n </div>\n \"\"\"\n css = \"\"\"\n .card {\n border: 1px solid gray;\n }\n \"\"\"\n js = \"console.log('Base card loaded');\"\n\n# This class overrides parent's template, but inherits CSS and JS\nclass SpecialCard(BaseCard):\n template = \"\"\"\n <div class=\"card special\">\n <div class=\"card-content\">\u2728 {{ content }} \u2728</div>\n </div>\n \"\"\"\n\n# This class overrides parent's template and CSS, but inherits JS\nclass CustomCard(BaseCard):\n template_file = \"custom_card.html\"\n css = \"\"\"\n .card {\n border: 2px solid gold;\n }\n \"\"\"\n
The
Component.Media
nested class follows Django's media inheritance rules:- If both parent and child define a
Media
class, the child's media will automatically include both its own and the parent's JS and CSS files. - This behavior can be configured using the
extend
attribute in the Media class, similar to Django's forms. Read more on this in Controlling Media Inheritance.
For example:
"},{"location":"concepts/fundamentals/subclassing_components/#regular-python-inheritance","title":"Regular Python Inheritance","text":"class BaseModal(Component):\n template = \"<div>Modal content</div>\"\n\n class Media:\n css = [\"base_modal.css\"]\n js = [\"base_modal.js\"] # Contains core modal functionality\n\nclass FancyModal(BaseModal):\n class Media:\n # Will include both base_modal.css/js AND fancy_modal.css/js\n css = [\"fancy_modal.css\"] # Additional styling\n js = [\"fancy_modal.js\"] # Additional animations\n\nclass SimpleModal(BaseModal):\n class Media:\n extend = False # Don't inherit parent's media\n css = [\"simple_modal.css\"] # Only this CSS will be included\n js = [\"simple_modal.js\"] # Only this JS will be included\n
All other attributes and methods (including the
Component.View
class and its methods) follow standard Python inheritance rules.For example:
"},{"location":"concepts/fundamentals/template_tag_syntax/","title":"Template tag syntax","text":"class BaseForm(Component):\n template = \"\"\"\n <form>\n {{ form_content }}\n <button type=\"submit\">\n {{ submit_text }}\n </button>\n </form>\n \"\"\"\n\n def get_context_data(self, **kwargs):\n return {\n \"form_content\": self.get_form_content(),\n \"submit_text\": \"Submit\"\n }\n\n def get_form_content(self):\n return \"<input type='text' name='data'>\"\n\nclass ContactForm(BaseForm):\n # Extend parent's \"context\"\n # but override \"submit_text\"\n def get_context_data(self, **kwargs):\n context = super().get_context_data(**kwargs)\n context[\"submit_text\"] = \"Send Message\" \n return context\n\n # Completely override parent's get_form_content\n def get_form_content(self):\n return \"\"\"\n <input type='text' name='name' placeholder='Your Name'>\n <input type='email' name='email' placeholder='Your Email'>\n <textarea name='message' placeholder='Your Message'></textarea>\n \"\"\"\n
All template tags in django_component, like
"},{"location":"concepts/fundamentals/template_tag_syntax/#self-closing-tags","title":"Self-closing tags","text":"{% component %}
or{% slot %}
, and so on, support extra syntax that makes it possible to write components like in Vue or React (JSX).When you have a tag like
{% component %}
or{% slot %}
, but it has no content, you can simply append a forward slash/
at the end, instead of writing out the closing tags like{% endcomponent %}
or{% endslot %}
:So this:
{% component \"button\" %}{% endcomponent %}\n
becomes
"},{"location":"concepts/fundamentals/template_tag_syntax/#special-characters","title":"Special characters","text":"{% component \"button\" / %}\n
New in version 0.71:
Keyword arguments can contain special characters
# @ . - _
, so keywords like so are still valid:<body>\n {% component \"calendar\" my-date=\"2015-06-19\" @click.native=do_something #some_id=True / %}\n</body>\n
These can then be accessed inside
get_context_data
so:
"},{"location":"concepts/fundamentals/template_tag_syntax/#spread-operator","title":"Spread operator","text":"@register(\"calendar\")\nclass Calendar(Component):\n # Since # . @ - are not valid identifiers, we have to\n # use `**kwargs` so the method can accept these args.\n def get_context_data(self, **kwargs):\n return {\n \"date\": kwargs[\"my-date\"],\n \"id\": kwargs[\"#some_id\"],\n \"on_click\": kwargs[\"@click.native\"]\n }\n
New in version 0.93:
Instead of passing keyword arguments one-by-one:
{% component \"calendar\" title=\"How to abc\" date=\"2015-06-19\" author=\"John Wick\" / %}\n
You can use a spread operator
...dict
to apply key-value pairs from a dictionary:post_data = {\n \"title\": \"How to...\",\n \"date\": \"2015-06-19\",\n \"author\": \"John Wick\",\n}\n
{% component \"calendar\" ...post_data / %}\n
This behaves similar to JSX's spread operator or Vue's
v-bind
.Spread operators are treated as keyword arguments, which means that:
- Spread operators must come after positional arguments.
- You cannot use spread operators for positional-only arguments.
Other than that, you can use spread operators multiple times, and even put keyword arguments in-between or after them:
{% component \"calendar\" ...post_data id=post.id ...extra / %}\n
In a case of conflicts, the values added later (right-most) overwrite previous values.
"},{"location":"concepts/fundamentals/template_tag_syntax/#use-template-tags-inside-component-inputs","title":"Use template tags inside component inputs","text":"New in version 0.93
When passing data around, sometimes you may need to do light transformations, like negating booleans or filtering lists.
Normally, what you would have to do is to define ALL the variables inside
get_context_data()
. But this can get messy if your components contain a lot of logic.@register(\"calendar\")\nclass Calendar(Component):\n def get_context_data(self, id: str, editable: bool):\n return {\n \"editable\": editable,\n \"readonly\": not editable,\n \"input_id\": f\"input-{id}\",\n \"icon_id\": f\"icon-{id}\",\n ...\n }\n
Instead, template tags in django_components (
{% component %}
,{% slot %}
,{% provide %}
, etc) allow you to treat literal string values as templates:{% component 'blog_post'\n \"As positional arg {# yay #}\"\n title=\"{{ person.first_name }} {{ person.last_name }}\"\n id=\"{% random_int 10 20 %}\"\n readonly=\"{{ editable|not }}\"\n author=\"John Wick {# TODO: parametrize #}\"\n/ %}\n
In the example above:
- Component
test
receives a positional argument with value\"As positional arg \"
. The comment is omitted. - Kwarg
title
is passed as a string, e.g.John Doe
- Kwarg
id
is passed asint
, e.g.15
- Kwarg
readonly
is passed asbool
, e.g.False
- Kwarg
author
is passed as a string, e.g.John Wick
(Comment omitted)
This is inspired by django-cotton.
"},{"location":"concepts/fundamentals/template_tag_syntax/#passing-data-as-string-vs-original-values","title":"Passing data as string vs original values","text":"Sometimes you may want to use the template tags to transform or generate the data that is then passed to the component.
The data doesn't necessarily have to be strings. In the example above, the kwarg
id
was passed as an integer, NOT a string.Although the string literals for components inputs are treated as regular Django templates, there is one special case:
When the string literal contains only a single template tag, with no extra text, then the value is passed as the original type instead of a string.
Here,
page
is an integer:{% component 'blog_post' page=\"{% random_int 10 20 %}\" / %}\n
Here,
page
is a string:{% component 'blog_post' page=\" {% random_int 10 20 %} \" / %}\n
And same applies to the
{{ }}
variable tags:Here,
items
is a list:{% component 'cat_list' items=\"{{ cats|slice:':2' }}\" / %}\n
Here,
items
is a string:
"},{"location":"concepts/fundamentals/template_tag_syntax/#evaluating-python-expressions-in-template","title":"Evaluating Python expressions in template","text":"{% component 'cat_list' items=\"{{ cats|slice:':2' }} See more\" / %}\n
You can even go a step further and have a similar experience to Vue or React, where you can evaluate arbitrary code expressions:
<MyForm value={isEnabled ? inputValue : null} />\n
Similar is possible with
django-expr
, which adds anexpr
tag and filter that you can use to evaluate Python expressions from within the template:{% component \"my_form\"\n value=\"{% expr 'input_value if is_enabled else None' %}\"\n/ %}\n
Note: Never use this feature to mix business logic and template logic. Business logic should still be in the view!
"},{"location":"concepts/fundamentals/template_tag_syntax/#pass-dictonary-by-its-key-value-pairs","title":"Pass dictonary by its key-value pairs","text":"New in version 0.74:
Sometimes, a component may expect a dictionary as one of its inputs.
Most commonly, this happens when a component accepts a dictionary of HTML attributes (usually called
attrs
) to pass to the underlying template.In such cases, we may want to define some HTML attributes statically, and other dynamically. But for that, we need to define this dictionary on Python side:
@register(\"my_comp\")\nclass MyComp(Component):\n template = \"\"\"\n {% component \"other\" attrs=attrs / %}\n \"\"\"\n\n def get_context_data(self, some_id: str):\n attrs = {\n \"class\": \"pa-4 flex\",\n \"data-some-id\": some_id,\n \"@click.stop\": \"onClickHandler\",\n }\n return {\"attrs\": attrs}\n
But as you can see in the case above, the event handler
@click.stop
and stylingpa-4 flex
are disconnected from the template. If the component grew in size and we moved the HTML to a separate file, we would have hard time reasoning about the component's template.Luckily, there's a better way.
When we want to pass a dictionary to a component, we can define individual key-value pairs as component kwargs, so we can keep all the relevant information in the template. For that, we prefix the key with the name of the dict and
:
. So keyclass
of inputattrs
becomesattrs:class
. And our example becomes:@register(\"my_comp\")\nclass MyComp(Component):\n template = \"\"\"\n {% component \"other\"\n attrs:class=\"pa-4 flex\"\n attrs:data-some-id=some_id\n attrs:@click.stop=\"onClickHandler\"\n / %}\n \"\"\"\n\n def get_context_data(self, some_id: str):\n return {\"some_id\": some_id}\n
Sweet! Now all the relevant HTML is inside the template, and we can move it to a separate file with confidence:
{% component \"other\"\n attrs:class=\"pa-4 flex\"\n attrs:data-some-id=some_id\n attrs:@click.stop=\"onClickHandler\"\n/ %}\n
Note: It is NOT possible to define nested dictionaries, so
attrs:my_key:two=2
would be interpreted as:
"},{"location":"concepts/fundamentals/template_tag_syntax/#multiline-tags","title":"Multiline tags","text":"{\"attrs\": {\"my_key:two\": 2}}\n
By default, Django expects a template tag to be defined on a single line.
However, this can become unwieldy if you have a component with a lot of inputs:
{% component \"card\" title=\"Joanne Arc\" subtitle=\"Head of Kitty Relations\" date_last_active=\"2024-09-03\" ... %}\n
Instead, when you install django_components, it automatically configures Django to suport multi-line tags.
So we can rewrite the above as:
{% component \"card\"\n title=\"Joanne Arc\"\n subtitle=\"Head of Kitty Relations\"\n date_last_active=\"2024-09-03\"\n ...\n%}\n
Much better!
To disable this behavior, set
"},{"location":"getting_started/adding_js_and_css/","title":"Adding JS and CSS","text":"COMPONENTS.multiline_tag
toFalse
Next we will add CSS and JavaScript to our template.
Info
In django-components, using JS and CSS is as simple as defining them on the Component class. You don't have to insert the
<script>
and<link>
tags into the HTML manually.Behind the scenes, django-components keeps track of which components use which JS and CSS files. Thus, when a component is rendered on the page, the page will contain only the JS and CSS used by the components, and nothing more!
"},{"location":"getting_started/adding_js_and_css/#1-update-project-structure","title":"1. Update project structure","text":"Start by creating empty
calendar.js
andcalendar.css
files:
"},{"location":"getting_started/adding_js_and_css/#2-write-css","title":"2. Write CSS","text":"sampleproject/\n\u251c\u2500\u2500 calendarapp/\n\u251c\u2500\u2500 components/\n\u2502 \u2514\u2500\u2500 calendar/\n\u2502 \u251c\u2500\u2500 calendar.py\n\u2502 \u251c\u2500\u2500 calendar.js \ud83c\udd95\n\u2502 \u251c\u2500\u2500 calendar.css \ud83c\udd95\n\u2502 \u2514\u2500\u2500 calendar.html\n\u251c\u2500\u2500 sampleproject/\n\u251c\u2500\u2500 manage.py\n\u2514\u2500\u2500 requirements.txt\n
Inside
[project root]/components/calendar/calendar.csscalendar.css
, write:.calendar {\n width: 200px;\n background: pink;\n}\n.calendar span {\n font-weight: bold;\n}\n
Be sure to prefix your rules with unique CSS class like
calendar
, so the CSS doesn't clash with other rules.Note
Soon, django-components will automatically scope your CSS by default, so you won't have to worry about CSS class clashes.
This CSS will be inserted into the page as an inlined
<style>
tag, at the position defined by{% component_css_dependencies %}
, or at the end of the inside the<head>
tag (See JS and CSS output locations).So in your HTML, you may see something like this:
"},{"location":"getting_started/adding_js_and_css/#3-write-js","title":"3. Write JS","text":"<html>\n <head>\n ...\n <style>\n .calendar {\n width: 200px;\n background: pink;\n }\n .calendar span {\n font-weight: bold;\n }\n </style>\n </head>\n <body>\n ...\n </body>\n</html>\n
Next we write a JavaScript file that specifies how to interact with this component.
You are free to use any javascript framework you want.
[project root]/components/calendar/calendar.js(function () {\n document.querySelector(\".calendar\").onclick = () => {\n alert(\"Clicked calendar!\");\n };\n})();\n
A good way to make sure the JS of this component doesn't clash with other components is to define all JS code inside an anonymous self-invoking function (
(() => { ... })()
). This makes all variables defined only be defined inside this component and not affect other components.Note
Soon, django-components will automatically wrap your JS in a self-invoking function by default (except for JS defined with
<script type=\"module\">
).Similarly to CSS, JS will be inserted into the page as an inlined
<script>
tag, at the position defined by{% component_js_dependencies %}
, or at the end of the inside the<body>
tag (See JS and CSS output locations).So in your HTML, you may see something like this:
"},{"location":"getting_started/adding_js_and_css/#rules-of-js-execution","title":"Rules of JS execution","text":"<html>\n <head>\n ...\n </head>\n <body>\n ...\n <script>\n (function () {\n document.querySelector(\".calendar\").onclick = () => {\n alert(\"Clicked calendar!\");\n };\n })();\n </script>\n </body>\n</html>\n
-
JS is executed in the order in which the components are found in the HTML
By default, the JS is inserted as a synchronous script (
<script> ... </script>
)So if you define multiple components on the same page, their JS will be executed in the order in which the components are found in the HTML.
So if we have a template like so:
<html>\n <head>\n ...\n </head>\n <body>\n {% component \"calendar\" / %}\n {% component \"table\" / %}\n </body>\n</html>\n
Then the JS file of the component
calendar
will be executed first, and the JS file of componenttable
will be executed second. -
JS will be executed only once, even if there is multiple instances of the same component
In this case, the JS of
calendar
will STILL execute first (because it was found first), and will STILL execute only once, even though it's present twice:<html>\n <head>\n ...\n </head>\n <body>\n {% component \"calendar\" / %}\n {% component \"table\" / %}\n {% component \"calendar\" / %}\n </body>\n</html>\n
Finally, we return to our Python component in
calendar.py
to tie this together.To link JS and CSS defined in other files, use
[project root]/components/calendar/calendar.pyjs_file
andcss_file
attributes:from django_components import Component\n\nclass Calendar(Component):\n template_file = \"calendar.html\"\n js_file = \"calendar.js\" # <--- new\n css_file = \"calendar.css\" # <--- new\n\n def get_context_data(self):\n return {\n \"date\": \"1970-01-01\",\n }\n
And that's it! If you were to embed this component in an HTML, django-components will automatically embed the associated JS and CSS.
Note
Similarly to the template file, the JS and CSS file paths can be either:
- Relative to the Python component file (as seen above),
- Relative to any of the component directories as defined by
COMPONENTS.dirs
and/orCOMPONENTS.app_dirs
(e.g.[your apps]/components
dir and[project root]/components
) - Relative to any of the directories defined by
STATICFILES_DIRS
.
Your components may depend on third-party packages or styling, or other shared logic. To load these additional dependencies, you can use a nested
Media
class.This
Media
class behaves similarly to Django's Media class, with a few differences:- Our Media class accepts various formats for the JS and CSS files: either a single file, a list, or (CSS-only) a dictonary (see below).
- Individual JS / CSS files can be any of
str
,bytes
,Path
,SafeString
, or a function. - If you set
Media.extend
to a list, it should be a list ofComponent
classes.
Learn more about using Media.
[project root]/components/calendar/calendar.pyfrom django_components import Component\n\nclass Calendar(Component):\n template_file = \"calendar.html\"\n js_file = \"calendar.js\"\n css_file = \"calendar.css\"\n\n class Media: # <--- new\n js = [\n \"path/to/shared.js\",\n \"https://unpkg.com/alpinejs@3.14.7/dist/cdn.min.js\", # AlpineJS\n ]\n css = [\n \"path/to/shared.css\",\n \"https://unpkg.com/tailwindcss@^2/dist/tailwind.min.css\", # Tailwind\n ]\n\n def get_context_data(self):\n return {\n \"date\": \"1970-01-01\",\n }\n
Note
Same as with the \"primary\" JS and CSS, the file paths files can be either:
- Relative to the Python component file (as seen above),
- Relative to any of the component directories as defined by
COMPONENTS.dirs
and/orCOMPONENTS.app_dirs
(e.g.[your apps]/components
dir and[project root]/components
)
Info
The
Media
nested class is shaped based on Django's Media class.As such, django-components allows multiple formats to define the nested Media class:
# Single files\nclass Media:\n js = \"calendar.js\"\n css = \"calendar.css\"\n\n# Lists of files\nclass Media:\n js = [\"calendar.js\", \"calendar2.js\"]\n css = [\"calendar.css\", \"calendar2.css\"]\n\n# Dictionary of media types for CSS\nclass Media:\n js = [\"calendar.js\", \"calendar2.js\"]\n css = {\n \"all\": [\"calendar.css\", \"calendar2.css\"],\n }\n
If you define a list of JS files, they will be executed one-by-one, left-to-right.
"},{"location":"getting_started/adding_js_and_css/#rules-of-execution-of-scripts-in-mediajs","title":"Rules of execution of scripts inMedia.js
","text":"The scripts defined in
Media.js
still follow the rules outlined above:- JS is executed in the order in which the components are found in the HTML.
- JS will be executed only once, even if there is multiple instances of the same component.
Additionally to
Media.js
applies that:- JS in
Media.js
is executed before the component's primary JS. - JS in
Media.js
is executed in the same order as it was defined. - If there is multiple components that specify the same JS path or URL in
Media.js
, this JS will be still loaded and executed only once.
Putting all of this together, our
Calendar
component above would render HTML like so:<html>\n <head>\n ...\n <!-- CSS from Media.css -->\n <link href=\"/static/path/to/shared.css\" media=\"all\" rel=\"stylesheet\" />\n <link\n href=\"https://unpkg.com/tailwindcss@^2/dist/tailwind.min.css\"\n media=\"all\"\n rel=\"stylesheet\"\n />\n <!-- CSS from Component.css_file -->\n <style>\n .calendar {\n width: 200px;\n background: pink;\n }\n .calendar span {\n font-weight: bold;\n }\n </style>\n </head>\n <body>\n ...\n <!-- JS from Media.js -->\n <script src=\"/static/path/to/shared.js\"></script>\n <script src=\"https://unpkg.com/alpinejs@3.14.7/dist/cdn.min.js\"></script>\n <!-- JS from Component.js_file -->\n <script>\n (function () {\n document.querySelector(\".calendar\").onclick = () => {\n alert(\"Clicked calendar!\");\n };\n })();\n </script>\n </body>\n</html>\n
Now that we have a fully-defined component, next let's use it in a Django template \u27a1\ufe0f.
"},{"location":"getting_started/adding_slots/","title":"Adding slots","text":"Our calendar component's looking great! But we just got a new assignment from our colleague - The calendar date needs to be shown on 3 different pages:
- On one page, it needs to be shown as is
- On the second, the date needs to be bold
- On the third, the date needs to be in italics
As a reminder, this is what the component's template looks like:
<div class=\"calendar\">\n Today's date is <span>{{ date }}</span>\n</div>\n
There's many ways we could approach this:
- Expose the date in a slot
- Style
.calendar > span
differently on different pages - Pass a variable to the component that decides how the date is rendered
- Create a new component
First two options are more flexible, because the custom styling is not baked into a component's implementation. And for the sake of demonstration, we'll solve this challenge with slots.
"},{"location":"getting_started/adding_slots/#1-what-are-slots","title":"1. What are slots","text":"Components support something called Slots.
When a component is used inside another template, slots allow the parent template to override specific parts of the child component by passing in different content.
This mechanism makes components more reusable and composable.
This behavior is similar to slots in Vue.
In the example below we introduce two tags that work hand in hand to make this work. These are...
{% slot <name> %}
/{% endslot %}
: Declares a new slot in the component template.{% fill <name> %}
/{% endfill %}
: (Used inside a{% component %}
tag pair.) Fills a declared slot with the specified content.
Let's update our calendar component to support more customization. We'll add
{% slot %}
tag to the template:<div class=\"calendar\">\n Today's date is\n {% slot \"date\" default %} {# <--- new #}\n <span>{{ date }}</span>\n {% endslot %}\n</div>\n
Notice that:
-
We named the slot
date
- so we can fill this slot by using{% fill \"date\" %}
-
We also made it the default slot.
-
We placed our original implementation inside the
{% slot %}
tag - this is what will be rendered when the slot is NOT overriden.
Now we can use
{% fill %}
tags inside the{% component %}
tags to override thedate
slot to generate the bold and italics variants:{# Default #}\n{% component \"calendar\" date=\"2024-12-13\" / %}\n\n{# Bold #}\n{% component \"calendar\" date=\"2024-12-13\" %}\n <b> 2024-12-13 </b>\n{% endcomponent %}\n\n{# Italics #}\n{% component \"calendar\" date=\"2024-12-13\" %}\n <i> 2024-12-13 </i>\n{% endcomponent %}\n
Which will render as:
<!-- Default -->\n<div class=\"calendar\">\n Today's date is <span>2024-12-13</span>\n</div>\n\n<!-- Bold -->\n<div class=\"calendar\">\n Today's date is <b>2024-12-13</b>\n</div>\n\n<!-- Italics -->\n<div class=\"calendar\">\n Today's date is <i>2024-12-13</i>\n</div>\n
Info
Since we used the
default
flag on{% slot \"date\" %}
inside our calendar component, we can target thedate
component in multiple ways:-
Explicitly by it's name
{% component \"calendar\" date=\"2024-12-13\" %}\n {% fill \"date\" %}\n <i> 2024-12-13 </i>\n {% endfill %}\n{% endcomponent %}\n
-
Implicitly as the default slot (Omitting the
{% fill %}
tag){% component \"calendar\" date=\"2024-12-13\" %}\n <i> 2024-12-13 </i>\n{% endcomponent %}\n
-
Explicitly as the default slot (Setting fill name to
default
){% component \"calendar\" date=\"2024-12-13\" %}\n {% fill \"default\" %}\n <i> 2024-12-13 </i>\n {% endfill %}\n{% endcomponent %}\n
There is a mistake in our code!
2024-12-13
is Friday, so that's fine. But if we updated the to2024-12-14
, which is Saturday, our template from previous step would render this:<!-- Default -->\n<div class=\"calendar\">\n Today's date is <span>2024-12-16</span>\n</div>\n\n<!-- Bold -->\n<div class=\"calendar\">\n Today's date is <b>2024-12-14</b>\n</div>\n\n<!-- Italics -->\n<div class=\"calendar\">\n Today's date is <i>2024-12-14</i>\n</div>\n
The first instance rendered
2024-12-16
, while the rest rendered2024-12-14
!Why? Remember that in the
[project root]/components/calendar/calendar.pyget_context_data()
method of our Calendar component, we pre-process the date. If the date falls on Saturday or Sunday, we shift it to next Monday:from datetime import date\n\nfrom django_components import Component, register\n\n# If date is Sat or Sun, shift it to next Mon, so the date is always workweek.\ndef to_workweek_date(d: date):\n ...\n\n@register(\"calendar\")\nclass Calendar(Component):\n template_file = \"calendar.html\"\n ...\n def get_context_data(self, date: date, extra_class: str | None = None):\n workweek_date = to_workweek_date(date)\n return {\n \"date\": workweek_date,\n \"extra_class\": extra_class,\n }\n
And the issue is that in our template, we used the
"},{"location":"getting_started/adding_slots/#5-adding-data-to-slots","title":"5. Adding data to slots","text":"date
value that we used as input, which is NOT the same as thedate
variable used inside Calendar's template.We want to use the same
date
variable that's used inside Calendar's template.Luckily, django-components allows passing data to the slot, also known as Scoped slots.
This consists of two steps:
- Pass the
date
variable to the{% slot %}
tag - Access the
date
variable in the{% fill %}
tag by using the specialdata
kwarg
Let's update the Calendar's template:
<div class=\"calendar\">\n Today's date is\n {% slot \"date\" default date=date %} {# <--- changed #}\n <span>{{ date }}</span>\n {% endslot %}\n</div>\n
Info
The
{% slot %}
tag has one special kwarg,name
. When you write{% slot \"date\" / %}\n
It's the same as:
{% slot name=\"date\" / %}\n
Other than the
name
kwarg, you can pass any extra kwargs to the{% slot %}
tag, and these will be exposed as the slot's data.
"},{"location":"getting_started/adding_slots/#6-accessing-slot-data-in-fills","title":"6. Accessing slot data in fills","text":"{% slot name=\"date\" kwarg1=123 kwarg2=\"text\" kwarg3=my_var / %}\n
Now, on the
{% fill %}
tags, we can use thedata
kwarg to specify the variable under which the slot data will be available.The variable from the
data
kwarg contains all the extra kwargs passed to the{% slot %}
tag.So if we set
data=\"slot_data\"
, then we can access the date variable underslot_data.date
:{# Default #}\n{% component \"calendar\" date=\"2024-12-13\" / %}\n\n{# Bold #}\n{% component \"calendar\" date=\"2024-12-13\" %}\n {% fill \"date\" data=\"slot_data\" %}\n <b> {{ slot_data.date }} </b>\n {% endfill %}\n{% endcomponent %}\n\n{# Italics #}\n{% component \"calendar\" date=\"2024-12-13\" %}\n {% fill \"date\" data=\"slot_data\" %}\n <i> {{ slot_data.date }} </i>\n {% endfill %}\n{% endcomponent %}\n
By using the
date
variable from the slot, we'll render the correct date each time:<!-- Default -->\n<div class=\"calendar\">\n Today's date is <span>2024-12-16</span>\n</div>\n\n<!-- Bold -->\n<div class=\"calendar\">\n Today's date is <b>2024-12-16</b>\n</div>\n\n<!-- Italics -->\n<div class=\"calendar\">\n Today's date is <i>2024-12-16</i>\n</div>\n
Info
When to use slots vs variables?
Generally, slots are more flexible - you can access the slot data, even the original slot content. Thus, slots behave more like functions that render content based on their context.
On the other hand, variables are static - the variable you pass to a component is what will be used.
Moreover, slots are treated as part of the template - for example the CSS scoping (work in progress) is applied to the slot content too.
"},{"location":"getting_started/components_in_templates/","title":"Components in templates","text":"By the end of this section, we want to be able to use our components in Django templates like so:
"},{"location":"getting_started/components_in_templates/#1-register-component","title":"1. Register component","text":"{% load component_tags %}\n<!DOCTYPE html>\n<html>\n <head>\n <title>My example calendar</title>\n </head>\n <body>\n {% component \"calendar\" / %}\n </body>\n<html>\n
First, however, we need to register our component class with
ComponentRegistry
.To register a component with a
[project root]/components/calendar/calendar.pyComponentRegistry
, we will use the@register
decorator, and give it a name under which the component will be accessible from within the template:from django_components import Component, register # <--- new\n\n@register(\"calendar\") # <--- new\nclass Calendar(Component):\n template_file = \"calendar.html\"\n js_file = \"calendar.js\"\n css_file = \"calendar.css\"\n\n def get_context_data(self):\n return {\n \"date\": \"1970-01-01\",\n }\n
This will register the component to the default registry. Default registry is loaded into the template by calling
{% load component_tags %}
inside the template.Info
Why do we have to register components?
We want to use our component as a template tag (
{% ... %}
) in Django template.In Django, template tags are managed by the
Library
instances. Whenever you include{% load xxx %}
in your template, you are loading aLibrary
instance into your template.ComponentRegistry
acts like a router and connects the registered components with the associatedLibrary
.That way, when you include
{% load component_tags %}
in your template, you are able to \"call\" components like{% component \"calendar\" / %}
.ComponentRegistries
also make it possible to group and share components as standalone packages. Learn more here.Note
You can create custom
ComponentRegistry
instances, which will use differentLibrary
instances. In that case you will have to load different libraries depending on which components you want to use:Example 1 - Using component defined in the default registry
{% load component_tags %}\n<div>\n {% component \"calendar\" / %}\n</div>\n
Example 2 - Using component defined in a custom registry
{% load my_custom_tags %}\n<div>\n {% my_component \"table\" / %}\n</div>\n
Note that, because the tag name
"},{"location":"getting_started/components_in_templates/#2-load-and-use-the-component-in-template","title":"2. Load and use the component in template","text":"component
is use by the default ComponentRegistry, the custom registry was configured to use the tagmy_component
instead. Read more hereThe component is now registered under the name
calendar
. All that remains to do is to load and render the component inside a template:{% load component_tags %} {# Load the default registry #}\n<!DOCTYPE html>\n<html>\n <head>\n <title>My example calendar</title>\n </head>\n <body>\n {% component \"calendar\" / %} {# Render the component #}\n </body>\n<html>\n
Info
Component tags should end with
/
if they do not contain any Slot fills. But you can also use{% endcomponent %}
instead:{% component \"calendar\" %}{% endcomponent %}\n
We defined the Calendar's template as
<div class=\"calendar\">\n Today's date is <span>{{ date }}</span>\n</div>\n
and the variable
date
as\"1970-01-01\"
.Thus, the final output will look something like this:
<!DOCTYPE html>\n<html>\n <head>\n <title>My example calendar</title>\n <style>\n .calendar {\n width: 200px;\n background: pink;\n }\n .calendar span {\n font-weight: bold;\n }\n </style>\n </head>\n <body>\n <div class=\"calendar\">\n Today's date is <span>1970-01-01</span>\n </div>\n <script>\n (function () {\n document.querySelector(\".calendar\").onclick = () => {\n alert(\"Clicked calendar!\");\n };\n })();\n </script>\n </body>\n<html>\n
This makes it possible to organize your front-end around reusable components, instead of relying on template tags and keeping your CSS and Javascript in the static directory.
Info
Remember that you can use
{% component_js_dependencies %}
and{% component_css_dependencies %}
to change where the<script>
and<style>
tags will be rendered (See JS and CSS output locations).Info
How does django-components pick up registered components?
Notice that it was enough to add
@register
to the component. We didn't need to import the component file anywhere to execute it.This is because django-components automatically imports all Python files found in the component directories during an event called Autodiscovery.
So with Autodiscovery, it's the same as if you manually imported the component files on the
ready()
hook:class MyApp(AppConfig):\n default_auto_field = \"django.db.models.BigAutoField\"\n name = \"myapp\"\n\n def ready(self):\n import myapp.components.calendar\n import myapp.components.table\n ...\n
You can now render the components in templates!
Currently our component always renders the same content. Let's parametrise it, so that our Calendar component is configurable from within the template \u27a1\ufe0f
"},{"location":"getting_started/parametrising_components/","title":"Parametrising components","text":"So far, our Calendar component will always render the date
1970-01-01
. Let's make it more useful and flexible by being able to pass in custom date.What we want is to be able to use the Calendar component within the template like so:
"},{"location":"getting_started/parametrising_components/#1-understading-component-inputs","title":"1. Understading component inputs","text":"{% component \"calendar\" date=\"2024-12-13\" extra_class=\"text-red\" / %}\n
In section Create your first component, we defined the
[project root]/components/calendar/calendar.pyget_context_data()
method that defines what variables will be available within the template:from django_components import Component, register\n\n@register(\"calendar\")\nclass Calendar(Component):\n template_file = \"calendar.html\"\n ...\n def get_context_data(self):\n return {\n \"date\": \"1970-01-01\",\n }\n
What we didn't say is that
get_context_data()
actually receives the args and kwargs that were passed to a component.So if we call a component with a
date
andextra_class
keywords:{% component \"calendar\" date=\"2024-12-13\" extra_class=\"text-red\" / %}\n
This is the same as calling:
Calendar.get_context_data(date=\"2024-12-13\", extra_class=\"text-red\")\n
And same applies to positional arguments, or mixing args and kwargs, where:
{% component \"calendar\" \"2024-12-13\" extra_class=\"text-red\" / %}\n
is same as
"},{"location":"getting_started/parametrising_components/#2-define-inputs-for-get_context_data","title":"2. Define inputs forCalendar.get_context_data(\"2024-12-13\", extra_class=\"text-red\")\n
get_context_data
","text":"Let's put this to test. We want to pass
[project root]/components/calendar/calendar.pydate
andextra_class
kwargs to the component. And so, we can write theget_context_data()
method such that it expects those parameters:from datetime import date\n\nfrom django_components import Component, register\n\n@register(\"calendar\")\nclass Calendar(Component):\n template_file = \"calendar.html\"\n ...\n def get_context_data(self, date: date, extra_class: str | None = None):\n return {\n \"date\": date,\n \"extra_class\": extra_class,\n }\n
Info
Since
get_context_data()
is just a regular Python function, type hints annotations work the same way as anywhere else.Warning
Since
get_context_data()
is just a regular Python function, it will raise TypeError if it receives incorrect parameters.Since
extra_class
is optional in the function signature, it's optional also in the template. So both following calls are valid:{% component \"calendar\" \"2024-12-13\" / %}\n{% component \"calendar\" \"2024-12-13\" extra_class=\"text-red\" / %}\n
However,
date
is required. Thus we MUST provide it. Same with regular Python functions,date
can be set either as positional or keyword argument. But either way it MUST be set:
"},{"location":"getting_started/parametrising_components/#3-process-inputs-in-get_context_data","title":"3. Process inputs in\u2705\n{% component \"calendar\" \"2024-12-13\" / %}\n{% component \"calendar\" extra_class=\"text-red\" date=\"2024-12-13\" / %}\n\n\u274c\n{% component \"calendar\" extra_class=\"text-red\" / %}\n
get_context_data
","text":"The
get_context_data()
method is powerful, because it allows us to decouple component inputs from the template variables. In other words, we can pre-process the component inputs, and massage them into a shape that's most appropriate for what the template needs. And it also allows us to pass in static data into the template.Imagine our component receives data from the database that looks like below (taken from Django).
cities = [\n {\"name\": \"Mumbai\", \"population\": \"19,000,000\", \"country\": \"India\"},\n {\"name\": \"Calcutta\", \"population\": \"15,000,000\", \"country\": \"India\"},\n {\"name\": \"New York\", \"population\": \"20,000,000\", \"country\": \"USA\"},\n {\"name\": \"Chicago\", \"population\": \"7,000,000\", \"country\": \"USA\"},\n {\"name\": \"Tokyo\", \"population\": \"33,000,000\", \"country\": \"Japan\"},\n]\n
We need to group the list items by size into following buckets by population:
- 0-10,000,000
- 10,000,001-20,000,000
- 20,000,001-30,000,000
- +30,000,001
So we want to end up with following data:
cities_by_pop = [\n {\n \"name\": \"0-10,000,000\",\n \"items\": [\n {\"name\": \"Chicago\", \"population\": \"7,000,000\", \"country\": \"USA\"},\n ]\n },\n {\n \"name\": \"10,000,001-20,000,000\",\n \"items\": [\n {\"name\": \"Calcutta\", \"population\": \"15,000,000\", \"country\": \"India\"},\n {\"name\": \"Mumbai\", \"population\": \"19,000,000\", \"country\": \"India\"},\n {\"name\": \"New York\", \"population\": \"20,000,000\", \"country\": \"USA\"},\n ]\n },\n {\n \"name\": \"30,000,001-40,000,000\",\n \"items\": [\n {\"name\": \"Tokyo\", \"population\": \"33,000,000\", \"country\": \"Japan\"},\n ]\n },\n]\n
Without the
get_context_data()
method, we'd have to either:- Pre-process the data in Python before passing it to the components.
- Define a Django filter or template tag to take the data and process it on the spot.
Instead, with
get_context_data()
, we can keep this transformation private to this component, and keep the rest of the codebase clean.def group_by_pop(data):\n ...\n\n@register(\"population_table\")\nclass PopulationTable(Component):\n template_file = \"population_table.html\"\n\n def get_context_data(self, data):\n return {\n \"data\": group_by_pop(data),\n }\n
Similarly we can make use of
[project root]/components/calendar/calendar.pyget_context_data()
to pre-process the date that was given to the component:
"},{"location":"getting_started/parametrising_components/#4-pass-inputs-to-components","title":"4. Pass inputs to components","text":"from datetime import date\n\nfrom django_components import Component, register\n\n# If date is Sat or Sun, shift it to next Mon, so the date is always workweek.\ndef to_workweek_date(d: date):\n ...\n\n@register(\"calendar\")\nclass Calendar(Component):\n template_file = \"calendar.html\"\n ...\n def get_context_data(self, date: date, extra_class: str | None = None):\n workweek_date = to_workweek_date(date) # <--- new\n return {\n \"date\": workweek_date, # <--- changed\n \"extra_class\": extra_class,\n }\n
Once we're happy with
Calendar.get_contex_data()
, we can update our templates to use the parametrized version of the component:<div>\n {% component \"calendar\" date=\"2024-12-13\" / %}\n {% component \"calendar\" date=\"1970-01-01\" / %}\n</div>\n
Next, you will learn how to use slots give your components even more flexibility \u27a1\ufe0f
"},{"location":"getting_started/your_first_component/","title":"Create your first component","text":"A component in django-components can be as simple as a Django template and Python code to declare the component:
calendar.html
calendar.py<div class=\"calendar\">\n Today's date is <span>{{ date }}</span>\n</div>\n
from django_components import Component\n\nclass Calendar(Component):\n template_file = \"calendar.html\"\n
Or a combination of Django template, Python, CSS, and Javascript:
calendar.html
calendar.css<div class=\"calendar\">\n Today's date is <span>{{ date }}</span>\n</div>\n
calendar.js.calendar {\n width: 200px;\n background: pink;\n}\n
calendar.pydocument.querySelector(\".calendar\").onclick = function () {\n alert(\"Clicked calendar!\");\n};\n
from django_components import Component\n\nclass Calendar(Component):\n template_file = \"calendar.html\"\n js_file = \"calendar.js\"\n css_file = \"calendar.css\"\n
Alternatively, you can \"inline\" HTML, JS, and CSS right into the component class:
from django_components import Component\n\nclass Calendar(Component):\n template = \"\"\"\n <div class=\"calendar\">\n Today's date is <span>{{ date }}</span>\n </div>\n \"\"\"\n\n css = \"\"\"\n .calendar {\n width: 200px;\n background: pink;\n }\n \"\"\"\n\n js = \"\"\"\n document.querySelector(\".calendar\").onclick = function () {\n alert(\"Clicked calendar!\");\n };\n \"\"\"\n
Note
If you \"inline\" the HTML, JS and CSS code into the Python class, you can set up syntax highlighting for better experience. However, autocompletion / intellisense does not work with syntax highlighting.
We'll start by creating a component that defines only a Django template:
"},{"location":"getting_started/your_first_component/#1-create-project-structure","title":"1. Create project structure","text":"Start by creating empty
calendar.py
andcalendar.html
files:
"},{"location":"getting_started/your_first_component/#2-write-django-template","title":"2. Write Django template","text":"sampleproject/\n\u251c\u2500\u2500 calendarapp/\n\u251c\u2500\u2500 components/ \ud83c\udd95\n\u2502 \u2514\u2500\u2500 calendar/ \ud83c\udd95\n\u2502 \u251c\u2500\u2500 calendar.py \ud83c\udd95\n\u2502 \u2514\u2500\u2500 calendar.html \ud83c\udd95\n\u251c\u2500\u2500 sampleproject/\n\u251c\u2500\u2500 manage.py\n\u2514\u2500\u2500 requirements.txt\n
Inside
[project root]/components/calendar/calendar.htmlcalendar.html
, write:<div class=\"calendar\">\n Today's date is <span>{{ date }}</span>\n</div>\n
In this example we've defined one template variable
date
. You can use any and as many variables as you like. These variables will be defined in the Python file inget_context_data()
when creating an instance of this component.Note
The template will be rendered with whatever template backend you've specified in your Django settings file.
Currently django-components supports only the default
"},{"location":"getting_started/your_first_component/#3-create-new-component-in-python","title":"3. Create new Component in Python","text":"\"django.template.backends.django.DjangoTemplates\"
template backend!In
calendar.py
, create a subclass of Component to create a new component.To link the HTML template with our component, set
[project root]/components/calendar/calendar.pytemplate_file
to the name of the HTML file.from django_components import Component\n\nclass Calendar(Component):\n template_file = \"calendar.html\"\n
Note
The path to the template file can be either:
- Relative to the component's python file (as seen above),
- Relative to any of the component directories as defined by
COMPONENTS.dirs
and/orCOMPONENTS.app_dirs
(e.g.[your apps]/components
dir and[project root]/components
)
In
calendar.html
, we've used the variabledate
. So we need to define it for the template to work.This is done using
[project root]/components/calendar/calendar.pyComponent.get_context_data()
. It's a function that returns a dictionary. The entries in this dictionary will become available within the template as variables, e.g. as{{ date }}
.from django_components import Component\n\nclass Calendar(Component):\n template_file = \"calendar.html\"\n\n def get_context_data(self):\n return {\n \"date\": \"1970-01-01\",\n }\n
Now, when we render the component with
Component.render()
method:Calendar.render()\n
It will output
<div class=\"calendar\">\n Today's date is <span>1970-01-01</span>\n</div>\n
And voil\u00e1!! We've created our first component.
Next, let's add JS and CSS to this component \u27a1\ufe0f.
"},{"location":"guides/devguides/dependency_mgmt/","title":"JS and CSS rendering","text":"Aim of this doc is to share the intuition on how we manage the JS and CSS (\"dependencies\") associated with components, and how we render them.
"},{"location":"guides/devguides/dependency_mgmt/#starting-conditions","title":"Starting conditions","text":"-
First of all, when we consider a component, it has two kind of dependencies - the \"inlined\" JS and CSS, and additional linked JS and CSS via
Media.js/css
:from django_components import Component, types\n\nclass MyTable(Component):\n # Inlined JS\n js: types.js = \"\"\"\n console.log(123);\n \"\"\"\n\n # Inlined CSS\n css: types.css = \"\"\"\n .my-table {\n color: red;\n }\n \"\"\"\n\n # Linked JS / CSS\n class Media:\n js = [\n \"script-one.js\", # STATIC file relative to component file\n \"/script-two.js\", # URL path\n \"https://example.com/script-three.js\", # URL\n ]\n\n css = [\n \"style-one.css\", # STATIC file relative to component file\n \"/style-two.css\", # URL path\n \"https://example.com/style-three.css\", # URL\n ]\n
-
Second thing to keep in mind is that all component's are eventually rendered into a string. And so, if we want to associate extra info with a rendered component, it has to be serialized to a string.
This is because a component may be embedded in a Django Template with the
{% component %}
tag, which, when rendered, is turned into a string:template = Template(\"\"\"\n {% load component_tags %}\n <div>\n {% component \"my_table\" / %}\n </div>\n\"\"\")\n\nhtml_str = template.render(Context({}))\n
And for this reason, we take the same approach also when we render a component with
Component.render()
- It returns a string. -
Thirdly, we also want to add support for JS / CSS variables. That is, that a variable defined on the component would be somehow accessible from within the JS script / CSS style.
A simple approach to this would be to modify the inlined JS / CSS directly, and insert them for each component. But if you had extremely large JS / CSS, and e.g. only a single JS / CSS variable that you want to insert, it would be wasteful to create a copy of the JS / CSS scripts for each component instance.
So instead, a preferred approach here is to defined and insert the inlined JS / CSS only once, and have some kind of mechanism on how we make correct the JS / CSS variables available only to the correct components.
-
Last important thing is that we want the JS / CSS dependencies to work also with HTML fragments.
So normally, e.g. when a user hits URL of a web page, the server renders full HTML document, with
<!doctype>
,<html>
,<head>
, and<body>
. In such case, we know about ALL JS and CSS dependencies at render time, so we can e.g. insert them into<head>
and<body>
ourselves.However this renders only the initial state. HTML fragments is a common pattern where interactivity is added to the web page by fetching and replacing bits of HTML on the main HTML document after some user action.
In the case of HTML fragments, the HTML is NOT a proper document, but only the HTML that will be inserted somewhere into the DOM.
The challenge here is that Django template for the HTML fragment MAY contain components, and these components MAY have inlined or linked JS and CSS.
def fragment_view(request):\n template = Template(\"\"\"\n {% load component_tags %}\n <div>\n {% component \"my_table\" / %}\n </div>\n \"\"\")\n\n fragment_str = template.render(Context({}))\n return HttpResponse(fragment_str, status=200)\n
User may use different libraries to fetch and insert the HTML fragments (e.g. HTMX, AlpineJS, ...). From our perspective, the only thing that we can reliably say is that we expect that the HTML fragment WILL be eventually inserted into the DOM.
So to include the corresponding JS and CSS, a simple approach could be to append them to the HTML as
<style>
and<script>
, e.g.:<!-- Original content -->\n<div>...</div>\n<!-- Associated CSS files -->\n<link href=\"http://...\" />\n<style>\n .my-class {\n color: red;\n }\n</style>\n<!-- Associated JS files -->\n<script src=\"http://...\"></script>\n<script>\n console.log(123);\n</script>\n
But this has a number of issues:
- The JS scripts would run for each instance of the component.
- Bloating of the HTML file, as each inlined JS or CSS would be included fully for each component.
- While this sound OK, this could really bloat the HTML files if we used a UI component library for the basic building blocks like buttons, lists, cards, etc.
So the solution should address all the points above. To achieve that, we manage the JS / CSS dependencies ourselves in the browser. So when a full HTML document is loaded, we keep track of which JS and CSS have been loaded. And when an HTML fragment is inserted, we check which JS / CSS dependencies it has, and load only those that have NOT been loaded yet.
This is how we achieve that:
-
When a component is rendered, it inserts an HTML comment containing metadata about the rendered component.
So a template like this
{% load component_tags %}\n<div>\n {% component \"my_table\" / %}\n</div>\n{% component \"button\" %}\n Click me!\n{% endcomponent %}\n
May actually render:
<div>\n <!-- _RENDERED \"my_table_10bc2c,c020ad\" -->\n <table>\n ...\n </table>\n</div>\n<!-- _RENDERED \"button_309dcf,31c0da\" -->\n<button>Click me!</button>\n
Each
<!-- _RENDERED -->
comment includes comma-separated data - a unique hash for the component class, e.g.my_table_10bc2c
, and the component ID, e.g.c020ad
.This way, we or the user can freely pass the rendered around or transform it, treating it as a string to add / remove / replace bits. As long as the
<!-- _RENDERED -->
comments remain in the rendered string, we will be able to deduce which JS and CSS dependencies the component needs. -
Post-process the rendered HTML, extracting the
<!-- _RENDERED -->
comments, and instead inserting the corresponding JS and CSS dependencies.If we dealt only with JS, then we could get away with processing the
<!-- _RENDERED -->
comments on the client (browser). However, the CSS needs to be processed still on the server, so the browser receives CSS styles already inserted as<style>
or<link>
HTML tags. Because if we do not do that, we get a flash of unstyled content, as there will be a delay between when the HTML page loaded and when the CSS was fetched and loaded.So, assuming that a user has already rendered their template, which still contains
<!-- _RENDERED -->
comments, we need to extract and process these comments.There's multiple ways to achieve this:
-
The approach recommended to the users is to use the
ComponentDependencyMiddleware
middleware, which scans all outgoing HTML, and post-processes the<!-- _RENDERED -->
comments. -
If users are using
Component.render()
orComponent.render_to_response()
, these post-process the<!-- _RENDERED -->
comments by default. -
NOTE: Users are able to opt out of the post-processing by setting
render_dependencies=False
. -
For advanced use cases, users may use
render_dependencies()
directly. This is the function that bothComponentDependencyMiddleware
andComponent.render()
call internally.
render_dependencies()
, whether called directly, via middleware or other way, does the following:-
Find all
<!-- _RENDERED -->
comments, and for each comment: -
Look up the corresponding component class.
-
Get the component's inlined JS / CSS from
Component.js/css
, and linked JS / CSS fromComponent.Media.js/css
. -
Generate JS script that loads the JS / CSS dependencies.
-
Insert the JS scripts either at the end of
<body>
, or in place of{% component_dependencies %}
/{% component_js_dependencies %}
tags. -
To avoid the flash of unstyled content, we need place the styles into the HTML instead of dynamically loading them from within a JS script. The CSS is placed either at the end of
<head>
, or in place of{% component_dependencies %}
/{% component_css_dependencies %}
-
We cache the component's inlined JS and CSS, so they can be fetched via an URL, so the inlined JS / CSS an be treated the same way as the JS / CSS dependencies set in
Component.Media.js/css
.- NOTE: While this is currently not entirely necessary, it opens up the doors for allowing plugins to post-process the inlined JS and CSS. Because after it has been post-processed, we need to store it somewhere.
-
-
Server returns the post-processed HTML.
-
In the browser, the generated JS script from step 2.4 is executed. It goes through all JS and CSS dependencies it was given. If some JS / CSS was already loaded, it is NOT fetched again. Otherwise it generates the corresponding
<script>
or<link>
HTML tags to load the JS / CSS dependencies.In the browser, the \"dependency manager JS\" may look like this:
// Load JS or CSS script if not loaded already\nComponents.loadJs('<script src=\"/abc/xyz/script.js\">');\nComponents.loadCss('<link href=\"/abc/xyz/style.css\">');\n\n// Or mark one as already-loaded, so it is ignored when\n// we call `loadJs`\nComponents.markScriptLoaded(\"js\", \"/abc/def\");\n
Note that
loadJs() / loadCss()
receive whole<script> / <link>
tags, not just the URL. This is because when Django'sMedia
class renders JS and CSS, it formats it as<script>
and<link>
tags. And we allow users to modify how the JS and CSS should be rendered into the<script>
and<link>
tags.So, if users decided to add an extra attribute to their
<script>
tags, e.g.<script defer src=\"http://...\"></script>
, then this way we make sure that thedefer
attribute will be present on the<script>
tag when it is inserted into the DOM at the time of loading the JS script. -
To be able to fetch component's inlined JS and CSS, django-components adds a URL path under:
/components/cache/<str:comp_cls_hash>.<str:script_type>/
E.g.
/components/cache/my_table_10bc2c.js/
This endpoint takes the component's unique hash, e.g.
my_table_10bc2c
, and looks up the component's inlined JS or CSS.
Thus, with this approach, we ensure that:
- All JS / CSS dependencies are loaded / executed only once.
- The approach is compatible with HTML fragments
- The approach is compatible with JS / CSS variables.
- Inlined JS / CSS may be post-processed by plugins
This doc serves as a primer on how component slots and fills are resolved.
"},{"location":"guides/devguides/slot_rendering/#flow","title":"Flow","text":"-
Imagine you have a template. Some kind of text, maybe HTML:
| ------\n| ---------\n| ----\n| -------\n
-
The template may contain some vars, tags, etc
| -- {{ my_var }} --\n| ---------\n| ----\n| -------\n
-
The template also contains some slots, etc
| -- {{ my_var }} --\n| ---------\n| -- {% slot \"myslot\" %} ---\n| -- {% endslot %} ---\n| ----\n| -- {% slot \"myslot2\" %} ---\n| -- {% endslot %} ---\n| -------\n
-
Slots may be nested
| -- {{ my_var }} --\n| -- ABC\n| -- {% slot \"myslot\" %} ---\n| ----- DEF {{ my_var }}\n| ----- {% slot \"myslot_inner\" %}\n| -------- GHI {{ my_var }}\n| ----- {% endslot %}\n| -- {% endslot %} ---\n| ----\n| -- {% slot \"myslot2\" %} ---\n| ---- JKL {{ my_var }}\n| -- {% endslot %} ---\n| -------\n
-
Some slots may be inside fills for other components
| -- {{ my_var }} --\n| -- ABC\n| -- {% slot \"myslot\" %}---\n| ----- DEF {{ my_var }}\n| ----- {% slot \"myslot_inner\" %}\n| -------- GHI {{ my_var }}\n| ----- {% endslot %}\n| -- {% endslot %} ---\n| ------\n| -- {% component \"mycomp\" %} ---\n| ---- {% slot \"myslot\" %} ---\n| ------- JKL {{ my_var }}\n| ------- {% slot \"myslot_inner\" %}\n| ---------- MNO {{ my_var }}\n| ------- {% endslot %}\n| ---- {% endslot %} ---\n| -- {% endcomponent %} ---\n| ----\n| -- {% slot \"myslot2\" %} ---\n| ---- PQR {{ my_var }}\n| -- {% endslot %} ---\n| -------\n
-
The names of the slots and fills may be defined using variables
| -- {% slot slot_name %} ---\n| ---- STU {{ my_var }}\n| -- {% endslot %} ---\n| -------\n
-
The slot and fill names may be defined using for loops or other variables defined within the template (e.g.
{% with %}
tag or{% ... as var %}
syntax)| -- {% for slot_name in slots %} ---\n| ---- {% slot slot_name %} ---\n| ------ STU {{ slot_name }}\n| ---- {% endslot %} ---\n| -- {% endfor %} ---\n| -------\n
-
Variables for names and for loops allow us implement \"passthrough slots\" - that is, taking all slots that our component received, and passing them to a child component, dynamically.
| -- {% component \"mycomp\" %} ---\n| ---- {% for slot_name in slots %} ---\n| ------ {% fill slot_name %} ---\n| -------- {% slot slot_name %} ---\n| ---------- XYZ {{ slot_name }}\n| --------- {% endslot %}\n| ------- {% endfill %}\n| ---- {% endfor %} ---\n| -- {% endcomponent %} ---\n| ----\n
-
Putting that all together, a document may look like this:
| -- {{ my_var }} --\n| -- ABC\n| -- {% slot \"myslot\" %}---\n| ----- DEF {{ my_var }}\n| ----- {% slot \"myslot_inner\" %}\n| -------- GHI {{ my_var }}\n| ----- {% endslot %}\n| -- {% endslot %} ---\n| ------\n| -- {% component \"mycomp\" %} ---\n| ---- {% slot \"myslot\" %} ---\n| ------- JKL {{ my_var }}\n| ------- {% slot \"myslot_inner\" %}\n| ---------- MNO {{ my_var }}\n| ------- {% endslot %}\n| ---- {% endslot %} ---\n| -- {% endcomponent %} ---\n| ----\n| -- {% slot \"myslot2\" %} ---\n| ---- PQR {{ my_var }}\n| -- {% endslot %} ---\n| -------\n| -- {% for slot_name in slots %} ---\n| ---- {% component \"mycomp\" %} ---\n| ------- {% slot slot_name %}\n| ---------- STU {{ slot_name }}\n| ------- {% endslot %}\n| ---- {% endcomponent %} ---\n| -- {% endfor %} ---\n| ----\n| -- {% component \"mycomp\" %} ---\n| ---- {% for slot_name in slots %} ---\n| ------ {% fill slot_name %} ---\n| -------- {% slot slot_name %} ---\n| ---------- XYZ {{ slot_name }}\n| --------- {% endslot %}\n| ------- {% endfill %}\n| ---- {% endfor %} ---\n| -- {% endcomponent %} ---\n| -------\n
-
Given the above, we want to render the slots with
{% fill %}
tag that were defined OUTSIDE of this template. How do I do that?NOTE: Before v0.110, slots were resolved statically, by walking down the Django Template and Nodes. However, this did not allow for using for loops or other variables defined in the template.
Currently, this consists of 2 steps:
-
If a component is rendered within a template using
{% component %}
tag, determine the given{% fill %}
tags in the component's body (the content in between{% component %}
and{% endcomponent %}
).After this step, we know about all the fills that were passed to the component.
-
Then we simply render the template as usual. And then we reach the
{% slot %}
tag, we search the context for the available fills.- If there IS a fill with the same name as the slot, we render the fill.
- If the slot is marked
default
, and there is a fill nameddefault
, then we render that. - Otherwise, we render the slot's default content.
-
-
Obtaining the fills from
{% fill %}
.When a component is rendered with
{% component %}
tag, and it has some content in between{% component %}
and{% endcomponent %}
, we want to figure out if that content is a default slot (no{% fill %}
used), or if there is a collection of named{% fill %}
tags:Default slot:
| -- {% component \"mycomp\" %} ---\n| ---- STU {{ slot_name }}\n| -- {% endcomponent %} ---\n
Named slots:
| -- {% component \"mycomp\" %} ---\n| ---- {% fill \"slot_a\" %}\n| ------ STU\n| ---- {% endslot %}\n| ---- {% fill \"slot_b\" %}\n| ------ XYZ\n| ---- {% endslot %}\n| -- {% endcomponent %} ---\n
To respect any forloops or other variables defined within the template to which the fills may have access, we:
- Render the content between
{% component %}
and{% endcomponent %}
using the context outside of the component. - When we reach a
{% fill %}
tag, we capture any variables that were created between the{% component %}
and{% fill %}
tags. - When we reach
{% fill %}
tag, we do not continue rendering deeper. Instead we make a record that we found the fill tag with given name, kwargs, etc. - After the rendering is done, we check if we've encountered any fills. If yes, we expect only named fills. If no, we assume that the the component's body is a default slot.
- Lastly we process the found fills, and make them available to the context, so any slots inside the component may access these fills.
- Render the content between
-
Rendering slots
Slot rendering works similarly to collecting fills, in a sense that we do not search for the slots ahead of the time, but instead let Django handle the rendering of the template, and we step in only when Django come across as
{% slot %}
tag.When we reach a slot tag, we search the context for the available fills.
- If there IS a fill with the same name as the slot, we render the fill.
- If the slot is marked
default
, and there is a fill nameddefault
, then we render that. - Otherwise, we render the slot's default content.
In previous section, we said that the
{% fill %}
tags should be already rendered by the time they are inserted into the{% slot %}
tags.This is not quite true. To help you understand, consider this complex case:
| -- {% for var in [1, 2, 3] %} ---\n| ---- {% component \"mycomp2\" %} ---\n| ------ {% fill \"first\" %}\n| ------- STU {{ my_var }}\n| ------- {{ var }}\n| ------ {% endfill %}\n| ------ {% fill \"second\" %}\n| -------- {% component var=var my_var=my_var %}\n| ---------- VWX {{ my_var }}\n| -------- {% endcomponent %}\n| ------ {% endfill %}\n| ---- {% endcomponent %} ---\n| -- {% endfor %} ---\n| -------\n
We want the forloop variables to be available inside the
{% fill %}
tags. Because of that, however, we CANNOT render the fills/slots in advance.Instead, our solution is closer to how Vue handles slots. In Vue, slots are effectively functions that accept a context variables and render some content.
While we do not wrap the logic in a function, we do PREPARE IN ADVANCE: 1. The content that should be rendered for each slot 2. The context variables from
get_context_data()
Thus, once we reach the
"},{"location":"guides/devguides/slots_and_blocks/","title":"Using{% slot %}
node, in it'srender()
method, we access the data above, and, depending on thecontext_behavior
setting, include the current context or not. For more info, seeSlotNode.render()
.slot
andblock
tags","text":"-
First let's clarify how
include
andextends
tags work inside components.When component template includes
include
orextends
tags, it's as if the \"included\" template was inlined. So if the \"included\" template containsslot
tags, then the component uses those slots.If you have a template
abc.html
:<div>\n hello\n {% slot \"body\" %}{% endslot %}\n</div>\n
And components that make use of
abc.html
viainclude
orextends
:from django_components import Component, register\n\n@register(\"my_comp_extends\")\nclass MyCompWithExtends(Component):\n template = \"\"\"{% extends \"abc.html\" %}\"\"\"\n\n@register(\"my_comp_include\")\nclass MyCompWithInclude(Component):\n template = \"\"\"{% include \"abc.html\" %}\"\"\"\n
Then you can set slot fill for the slot imported via
include/extends
:{% component \"my_comp_extends\" %}\n {% fill \"body\" %}\n 123\n {% endfill %}\n{% endcomponent %}\n
And it will render:
<div>\n hello\n 123\n</div>\n
-
Slot and block
If you have a template
abc.html
like so:<div>\n hello\n {% block inner %}\n 1\n {% slot \"body\" %}\n 2\n {% endslot %}\n {% endblock %}\n</div>\n
and component
my_comp
:@register(\"my_comp\")\nclass MyComp(Component):\n template_file = \"abc.html\"\n
Then:
-
Since the
block
wasn't overriden, you can use thebody
slot:{% component \"my_comp\" %}\n {% fill \"body\" %}\n XYZ\n {% endfill %}\n{% endcomponent %}\n
And we get:
<div>hello 1 XYZ</div>\n
-
blocks
CANNOT be overriden through thecomponent
tag, so something like this:{% component \"my_comp\" %}\n {% fill \"body\" %}\n XYZ\n {% endfill %}\n{% endcomponent %}\n{% block \"inner\" %}\n 456\n{% endblock %}\n
Will still render the component content just the same:
<div>hello 1 XYZ</div>\n
-
You CAN override the
block
tags ofabc.html
if the component template usesextends
. In that case, just as you would expect, theblock inner
insideabc.html
will renderOVERRIDEN
:@register(\"my_comp\")\nclass MyComp(Component):\ntemplate_file = \"\"\"\n{% extends \"abc.html\" %}\n\n {% block inner %}\n OVERRIDEN\n {% endblock %}\n \"\"\"\n ```\n
-
This is where it gets interesting (but still intuitive). You can insert even new
slots
inside these \"overriding\" blocks:@register(\"my_comp\")\nclass MyComp(Component):\n template_file = \"\"\"\n {% extends \"abc.html\" %}\n\n {% load component_tags %}\n {% block \"inner\" %}\n OVERRIDEN\n {% slot \"new_slot\" %}\n hello\n {% endslot %}\n {% endblock %}\n \"\"\"\n
And you can then pass fill for this
new_slot
when rendering the component:{% component \"my_comp\" %}\n {% fill \"new_slot\" %}\n XYZ\n {% endfill %}\n{% endcomponent %}\n
NOTE: Currently you can supply fills for both
new_slot
andbody
slots, and you will not get an error for an invalid/unknown slot name. But sincebody
slot is not rendered, it just won't do anything. So this renders the same as above:{% component \"my_comp\" %}\n {% fill \"new_slot\" %}\n XYZ\n {% endfill %}\n {% fill \"body\" %}\n www\n {% endfill %}\n{% endcomponent %}\n
-
As larger projects get more complex, it can be hard to debug issues. Django Components provides a number of tools and approaches that can help you with that.
"},{"location":"guides/other/troubleshooting/#component-and-slot-highlighting","title":"Component and slot highlighting","text":"Django Components provides a visual debugging feature that helps you understand the structure and boundaries of your components and slots. When enabled, it adds a colored border and a label around each component and slot on your rendered page.
To enable component and slot highlighting, set
debug_highlight_components
and/ordebug_highlight_slots
toTrue
in yoursettings.py
file:from django_components import ComponentsSettings\n\nCOMPONENTS = ComponentsSettings(\n debug_highlight_components=True,\n debug_highlight_slots=True,\n)\n
Components will be highlighted with a blue border and label:
While the slots will be highlighted with a red border and label:
Warning
Use this feature ONLY in during development. Do NOT use it in production.
"},{"location":"guides/other/troubleshooting/#component-path-in-errors","title":"Component path in errors","text":"When an error occurs, the error message will show the path to the component that caused the error. E.g.
KeyError: \"An error occured while rendering components MyPage > MyLayout > MyComponent > Childomponent(slot:content)\n
The error message contains also the slot paths, so if you have a template like this:
{% component \"my_page\" %}\n {% slot \"content\" %}\n {% component \"table\" %}\n {% slot \"header\" %}\n {% component \"table_header\" %}\n ... {# ERROR HERE #}\n {% endcomponent %}\n {% endslot %}\n {% endcomponent %}\n {% endslot %}\n{% endcomponent %}\n
Then the error message will show the path to the component that caused the error:
"},{"location":"guides/other/troubleshooting/#debug-and-trace-logging","title":"Debug and trace logging","text":"KeyError: \"An error occured while rendering components my_page > layout > layout(slot:content) > my_page(slot:content) > table > table(slot:header) > table_header > table_header(slot:content)\n
Django components supports logging with Django.
To configure logging for Django components, set the
django_components
logger inLOGGING
insettings.py
(below).Also see the
settings.py
file in sampleproject for a real-life example.import logging\nimport sys\n\nLOGGING = {\n 'version': 1,\n 'disable_existing_loggers': False,\n \"handlers\": {\n \"console\": {\n 'class': 'logging.StreamHandler',\n 'stream': sys.stdout,\n },\n },\n \"loggers\": {\n \"django_components\": {\n \"level\": logging.DEBUG,\n \"handlers\": [\"console\"],\n },\n },\n}\n
Info
To set TRACE level, set
\"level\"
to5
:
"},{"location":"guides/other/troubleshooting/#logger-levels","title":"Logger levels","text":"LOGGING = {\n \"loggers\": {\n \"django_components\": {\n \"level\": 5,\n \"handlers\": [\"console\"],\n },\n },\n}\n
As of v0.126, django-components primarily uses these logger levels:
DEBUG
: Report on loading associated HTML / JS / CSS files, autodiscovery, etc.TRACE
: Detailed interaction of components and slots. Logs when template tags, components, and slots are started / ended rendering, and when a slot is filled.
When you pass a slot fill to a Component, the component and slot names is remebered on the slot object.
Thus, you can check where a slot was filled from by printing it out:
class MyComponent(Component):\n def on_render_before(self):\n print(self.input.slots)\n
might print:
"},{"location":"guides/other/troubleshooting/#agentic-debugging","title":"Agentic debugging","text":"{\n 'content': <Slot component_name='layout' slot_name='content'>,\n 'header': <Slot component_name='my_page' slot_name='header'>,\n 'left_panel': <Slot component_name='layout' slot_name='left_panel'>,\n}\n
All the features above make django-components to work really well with coding AI agents like Github Copilot or CursorAI.
To debug component rendering with LLMs, you want to provide the LLM with:
- The components source code
- The rendered output
- As much additional context as possible
Your codebase already contains the components source code, but not the latter two.
"},{"location":"guides/other/troubleshooting/#providing-rendered-output","title":"Providing rendered output","text":"To provide the LLM with the rendered output, you can simply export the rendered output to a file.
rendered = ProjectPage.render(...)\nwith open(\"result.html\", \"w\") as f:\n f.write(rendered)\n
If you're using
render_to_response
, access the output from theHttpResponse
object:
"},{"location":"guides/other/troubleshooting/#providing-contextual-logs","title":"Providing contextual logs","text":"response = ProjectPage.render_to_response(...)\nwith open(\"result.html\", \"wb\") as f:\n f.write(response.content)\n
Next, we provide the agent with info on HOW we got the result that we have. We do so by providing the agent with the trace-level logs.
In your
settings.py
, configure the trace-level logs to be written to thedjango_components.log
file:
"},{"location":"guides/other/troubleshooting/#prompting-the-agent","title":"Prompting the agent","text":"LOGGING = {\n \"version\": 1,\n \"disable_existing_loggers\": False,\n \"handlers\": {\n \"file\": {\n \"class\": \"logging.FileHandler\",\n \"filename\": \"django_components.log\",\n \"mode\": \"w\", # Overwrite the file each time\n },\n },\n \"loggers\": {\n \"django_components\": {\n \"level\": 5,\n \"handlers\": [\"file\"],\n },\n },\n}\n
Now, you can prompt the agent and include the trace log and the rendered output to guide the agent with debugging.
I have a django-components (DJC) project. DJC is like if Vue or React component-based web development but made for Django ecosystem.
In the view
project_view
, I am rendering theProjectPage
component. However, the output is not as expected. The output is missing the tabs.You have access to the full log trace in
django_components.log
.You can also see the rendered output in
result.html
.With this information, help me debug the issue.
First, tell me what kind of info you would be looking for in the logs, and why (how it relates to understanding the cause of the bug).
Then tell me if that info was there, and what the implications are.
Finally, tell me what you would do to fix the issue.
"},{"location":"guides/setup/caching/","title":"Caching","text":"This page describes the kinds of assets that django-components caches and how to configure the cache backends.
"},{"location":"guides/setup/caching/#components-js-and-css-files","title":"Component's JS and CSS files","text":"django-components caches the JS and CSS files associated with your components. This enables components to be rendered as HTML fragments and still having the associated JS and CSS files loaded with them.
This includes:
- Inlined JS/CSS defined via
Component.js
andComponent.css
- JS/CSS variables generated from
get_js_data()
andget_css_data()
By default, django-components uses Django's local memory cache backend to store these assets. You can configure it to use any of your Django cache backends by setting the
COMPONENTS.cache
option in your settings:COMPONENTS = {\n # Name of the cache backend to use\n \"cache\": \"my-cache-backend\",\n}\n
The value should be the name of one of your configured cache backends from Django's
CACHES
setting.For example, to use Redis for caching component assets:
CACHES = {\n \"default\": {\n \"BACKEND\": \"django.core.cache.backends.locmem.LocMemCache\",\n },\n \"component-media\": {\n \"BACKEND\": \"django.core.cache.backends.redis.RedisCache\",\n \"LOCATION\": \"redis://127.0.0.1:6379/1\",\n }\n}\n\nCOMPONENTS = {\n # Use the Redis cache backend\n \"cache\": \"component-media\",\n}\n
See
"},{"location":"guides/setup/development_server/","title":"Development server","text":""},{"location":"guides/setup/development_server/#reload-dev-server-on-component-file-changes","title":"Reload dev server on component file changes","text":"COMPONENTS.cache
for more details about this setting.This is relevant if you are using the project structure as shown in our examples, where HTML, JS, CSS and Python are in separate files and nested in a directory.
In this case you may notice that when you are running a development server, the server sometimes does not reload when you change component files.
From relevant StackOverflow thread:
TL;DR is that the server won't reload if it thinks the changed file is in a templates directory, or in a nested sub directory of a templates directory. This is by design.
To make the dev server reload on all component files, set
reload_on_file_change
toTrue
. This configures Django to watch for component files too.Note
This setting should be enabled only for the dev environment!
"},{"location":"guides/setup/syntax_highlight/","title":"Syntax highlighting","text":""},{"location":"guides/setup/syntax_highlight/#vscode","title":"VSCode","text":"-
First install Python Inline Source Syntax Highlighting extension, it will give you syntax highlighting for the template, CSS, and JS.
-
Next, in your component, set typings of
Component.template/css/js
totypes.django_html
,types.css
, andtypes.js
respectively. The extension will recognize these and will activate syntax highlighting.
"},{"location":"guides/setup/syntax_highlight/#pycharm-or-other-jetbrains-ides","title":"Pycharm (or other Jetbrains IDEs)","text":"# In a file called [project root]/components/calendar.py\nfrom django_components import Component, register, types\n\n@register(\"calendar\")\nclass Calendar(Component):\n def get_context_data(self, date):\n return {\n \"date\": date,\n }\n\n template: types.django_html = \"\"\"\n <div class=\"calendar-component\">Today's date is <span>{{ date }}</span></div>\n \"\"\"\n\n css: types.css = \"\"\"\n .calendar-component { width: 200px; background: pink; }\n .calendar-component span { font-weight: bold; }\n \"\"\"\n\n js: types.js = \"\"\"\n (function(){\n if (document.querySelector(\".calendar-component\")) {\n document.querySelector(\".calendar-component\").onclick = function(){ alert(\"Clicked calendar!\"); };\n }\n })()\n \"\"\"\n
With PyCharm (or any other editor from Jetbrains), you don't need to use
types.django_html
,types.css
,types.js
since Pycharm uses language injections. You only need to write the comments# language=<lang>
above the variables.
"},{"location":"overview/code_of_conduct/","title":"Contributor Covenant Code of Conduct","text":""},{"location":"overview/code_of_conduct/#our-pledge","title":"Our Pledge","text":"from django_components import Component, register\n\n@register(\"calendar\")\nclass Calendar(Component):\n def get_context_data(self, date):\n return {\n \"date\": date,\n }\n\n # language=HTML\n template= \"\"\"\n <div class=\"calendar-component\">Today's date is <span>{{ date }}</span></div>\n \"\"\"\n\n # language=CSS\n css = \"\"\"\n .calendar-component { width: 200px; background: pink; }\n .calendar-component span { font-weight: bold; }\n \"\"\"\n\n # language=JS\n js = \"\"\"\n (function(){\n if (document.querySelector(\".calendar-component\")) {\n document.querySelector(\".calendar-component\").onclick = function(){ alert(\"Clicked calendar!\"); };\n }\n })()\n \"\"\"\n
In the interest of fostering an open and welcoming environment, we as contributors and maintainers pledge to making participation in our project and our community a harassment-free experience for everyone, regardless of age, body size, disability, ethnicity, sex characteristics, gender identity and expression, level of experience, education, socio-economic status, nationality, personal appearance, race, religion, or sexual identity and orientation.
"},{"location":"overview/code_of_conduct/#our-standards","title":"Our Standards","text":"Examples of behavior that contributes to creating a positive environment include:
- Using welcoming and inclusive language
- Being respectful of differing viewpoints and experiences
- Gracefully accepting constructive criticism
- Focusing on what is best for the community
- Showing empathy towards other community members
Examples of unacceptable behavior by participants include:
- The use of sexualized language or imagery and unwelcome sexual attention or advances
- Trolling, insulting/derogatory comments, and personal or political attacks
- Public or private harassment
- Publishing others' private information, such as a physical or electronic address, without explicit permission
- Other conduct which could reasonably be considered inappropriate in a professional setting
Project maintainers are responsible for clarifying the standards of acceptable behavior and are expected to take appropriate and fair corrective action in response to any instances of unacceptable behavior.
Project maintainers have the right and responsibility to remove, edit, or reject comments, commits, code, wiki edits, issues, and other contributions that are not aligned to this Code of Conduct, or to ban temporarily or permanently any contributor for other behaviors that they deem inappropriate, threatening, offensive, or harmful.
"},{"location":"overview/code_of_conduct/#scope","title":"Scope","text":"This Code of Conduct applies both within project spaces and in public spaces when an individual is representing the project or its community. Examples of representing a project or community include using an official project e-mail address, posting via an official social media account, or acting as an appointed representative at an online or offline event. Representation of a project may be further defined and clarified by project maintainers.
"},{"location":"overview/code_of_conduct/#enforcement","title":"Enforcement","text":"Instances of abusive, harassing, or otherwise unacceptable behavior may be reported by contacting the project team at emil@emilstenstrom.se. All complaints will be reviewed and investigated and will result in a response that is deemed necessary and appropriate to the circumstances. The project team is obligated to maintain confidentiality with regard to the reporter of an incident. Further details of specific enforcement policies may be posted separately.
Project maintainers who do not follow or enforce the Code of Conduct in good faith may face temporary or permanent repercussions as determined by other members of the project's leadership.
"},{"location":"overview/code_of_conduct/#attribution","title":"Attribution","text":"This Code of Conduct is adapted from the Contributor Covenant, version 1.4, available at https://www.contributor-covenant.org/version/1/4/code-of-conduct.html
For answers to common questions about this code of conduct, see https://www.contributor-covenant.org/faq
"},{"location":"overview/community/","title":"Community","text":""},{"location":"overview/community/#community-questions","title":"Community questions","text":"The best place to ask questions is in our Github Discussion board.
Please, before opening a new discussion, check if similar discussion wasn't opened already.
"},{"location":"overview/community/#community-examples","title":"Community examples","text":"One of our goals with
django-components
is to make it easy to share components between projects (see how to package components). If you have a set of components that you think would be useful to others, please open a pull request to add them to the list below.-
django-htmx-components: A set of components for use with htmx. Try out the live demo.
-
djc-heroicons: A component that renders icons from Heroicons.com.
Django-components supports all supported combinations versions of Django and Python.
Python version Django version 3.8 4.2 3.9 4.2 3.10 4.2, 5.0, 5.1 3.11 4.2, 5.0, 5.1 3.12 4.2, 5.0, 5.1 3.13 5.1"},{"location":"overview/contributing/","title":"Contributing","text":""},{"location":"overview/contributing/#bug-reports","title":"Bug reports","text":"If you find a bug, please open an issue with detailed description of what happened.
"},{"location":"overview/contributing/#bug-fixes","title":"Bug fixes","text":"If you found a fix for a bug or typo, go ahead and open a PR with a fix. We'll help you out with the rest!
"},{"location":"overview/contributing/#feature-requests","title":"Feature requests","text":"For feature requests or suggestions, please open either a discussion or an issue.
"},{"location":"overview/contributing/#getting-involved","title":"Getting involved","text":"django_components is still under active development, and there's much to build, so come aboard!
"},{"location":"overview/contributing/#sponsoring","title":"Sponsoring","text":"Another way you can get involved is by donating to the development of django_components.
"},{"location":"overview/development/","title":"Development","text":""},{"location":"overview/development/#install-locally-and-run-the-tests","title":"Install locally and run the tests","text":"Start by forking the project by clicking the Fork button up in the right corner in the GitHub. This makes a copy of the repository in your own name. Now you can clone this repository locally and start adding features:
git clone https://github.com/<your GitHub username>/django-components.git\ncd django-components\n
To quickly run the tests install the local dependencies by running:
pip install -r requirements-dev.txt\n
You also have to install this local django-components version. Use
-e
for editable mode so you don't have to re-install after every change:pip install -e .\n
Now you can run the tests to make sure everything works as expected:
pytest\n
The library is also tested across many versions of Python and Django. To run tests that way:
pyenv install -s 3.8\npyenv install -s 3.9\npyenv install -s 3.10\npyenv install -s 3.11\npyenv install -s 3.12\npyenv install -s 3.13\npyenv local 3.8 3.9 3.10 3.11 3.12 3.13\ntox -p\n
To run tests for a specific Python version, use:
tox -e py38\n
NOTE: See the available environments in
tox.ini
.And to run only linters, use:
"},{"location":"overview/development/#running-playwright-tests","title":"Running Playwright tests","text":"tox -e mypy,flake8,isort,black\n
We use Playwright for end-to-end tests. You will therefore need to install Playwright to be able to run these tests.
Luckily, Playwright makes it very easy:
pip install -r requirements-dev.txt\nplaywright install chromium --with-deps\n
After Playwright is ready, simply run the tests with
tox
:
"},{"location":"overview/development/#developing-against-live-django-app","title":"Developing against live Django app","text":"tox\n
How do you check that your changes to django-components project will work in an actual Django project?
Use the sampleproject demo project to validate the changes:
-
Navigate to sampleproject directory:
cd sampleproject\n
-
Install dependencies from the requirements.txt file:
pip install -r requirements.txt\n
-
Link to your local version of django-components:
pip install -e ..\n
Note
The path to the local version (in this case
..
) must point to the directory that has thesetup.py
file. -
Start Django server
python manage.py runserver\n
Once the server is up, it should be available at http://127.0.0.1:8000.
To display individual components, add them to the
"},{"location":"overview/development/#building-js-code","title":"Building JS code","text":"urls.py
, like in the case of http://127.0.0.1:8000/greetingdjango_components uses a bit of JS code to:
- Manage the loading of JS and CSS files used by the components
- Allow to pass data from Python to JS
When you make changes to this JS code, you also need to compile it:
-
Make sure you are inside
src/django_components_js
:cd src/django_components_js\n
-
Install the JS dependencies
npm install\n
-
Compile the JS/TS code:
python build.py\n
The script will combine all JS/TS code into a single
.js
file, minify it, and copy it todjango_components/static/django_components/django_components.min.js
.
To package the library into a distribution that can be published to PyPI, run:
# Install pypa/build\npython -m pip install build --user\n# Build a binary wheel and a source tarball\npython -m build --sdist --wheel --outdir dist/ .\n
To publish the package to PyPI, use
twine
(See Python user guide):twine upload --repository pypi dist/* -u __token__ -p <PyPI_TOKEN>\n
See the full workflow here.
"},{"location":"overview/development/#development-guides","title":"Development guides","text":"Head over to Dev guides for a deep dive into how django_components' features are implemented.
"},{"location":"overview/installation/","title":"Installation","text":"-
Install
django_components
into your environment:pip install django_components\n
-
Load
django_components
into Django by adding it intoINSTALLED_APPS
in in your settings file:INSTALLED_APPS = [\n ...,\n 'django_components',\n]\n
-
BASE_DIR
setting is required. Ensure that it is defined:from pathlib import Path\n\nBASE_DIR = Path(__file__).resolve().parent.parent\n
-
Optional. Set
COMPONENTS.dirs
and/orCOMPONENTS.app_dirs
so django_components knows where to find component HTML, JS and CSS files:If
COMPONENTS.dirs
is omitted, django-components will by default look for a top-level/components
directory,{BASE_DIR}/components
.from django_components import ComponentsSettings\n\nCOMPONENTS = ComponentsSettings(\n dirs=[\n ...,\n Path(BASE_DIR) / \"components\",\n ],\n)\n
In addition to
COMPONENTS.dirs
, django_components will also load components from app-level directories, such asmy-app/components/
. The directories within apps are configured withCOMPONENTS.app_dirs
, and the default is[app]/components
.Note
The input to
COMPONENTS.dirs
is the same as forSTATICFILES_DIRS
, and the paths must be full paths. See Django docs. -
Next, modify
TEMPLATES
section of settings.py as follows:- Remove
'APP_DIRS': True,
- NOTE: Instead of
APP_DIRS: True
, we will usedjango.template.loaders.app_directories.Loader
, which has the same effect.
- NOTE: Instead of
- Add
loaders
toOPTIONS
list and set it to following value:
This allows Django to load component HTML files as Django templates.
TEMPLATES = [\n {\n ...,\n 'OPTIONS': {\n 'loaders':[(\n 'django.template.loaders.cached.Loader', [\n # Default Django loader\n 'django.template.loaders.filesystem.Loader',\n # Including this is the same as APP_DIRS=True\n 'django.template.loaders.app_directories.Loader',\n # Components loader\n 'django_components.template_loader.Loader',\n ]\n )],\n },\n },\n]\n
- Remove
If you want to use JS or CSS with components, you will need to:
-
Add
\"django_components.finders.ComponentsFileSystemFinder\"
toSTATICFILES_FINDERS
in your settings file.This allows Django to serve component JS and CSS as static files.
STATICFILES_FINDERS = [\n # Default finders\n \"django.contrib.staticfiles.finders.FileSystemFinder\",\n \"django.contrib.staticfiles.finders.AppDirectoriesFinder\",\n # Django components\n \"django_components.finders.ComponentsFileSystemFinder\",\n]\n
-
Add
ComponentDependencyMiddleware
toMIDDLEWARE
setting.The middleware searches the outgoing HTML for all components that were rendered to generate the HTML, and adds the JS and CSS associated with those components.
MIDDLEWARE = [\n ...\n \"django_components.middleware.ComponentDependencyMiddleware\",\n]\n
Read more in Rendering JS/CSS dependencies.
-
Add django-component's URL paths to your
urlpatterns
:from django.urls import include, path\n\nurlpatterns = [\n ...\n path(\"\", include(\"django_components.urls\")),\n]\n
-
Optional. If you want to change where the JS and CSS is rendered, use
{% component_js_dependencies %}
and{% component_css_dependencies %}
.By default, the JS
<script>
and CSS<link>
tags are automatically inserted into the HTML (See JS and CSS output locations).<!doctype html>\n<html>\n <head>\n ...\n {% component_css_dependencies %}\n </head>\n <body>\n ...\n {% component_js_dependencies %}\n </body>\n</html>\n
-
Optional. By default, components' JS and CSS files are cached in memory.
If you want to change the cache backend, set the
COMPONENTS.cache
setting.Read more in Caching.
To avoid loading the app in each template using
{% load component_tags %}
, you can add the tag as a 'builtin' in settings.pyTEMPLATES = [\n {\n ...,\n 'OPTIONS': {\n 'builtins': [\n 'django_components.templatetags.component_tags',\n ]\n },\n },\n]\n
Now you're all set! Read on to find out how to build your first component.
"},{"location":"overview/license/","title":"License","text":"MIT License
Copyright (c) 2019 Emil Stenstr\u00f6m
Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the \"Software\"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:
The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED \"AS IS\", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
"},{"location":"overview/security_notes/","title":"Security notes \ud83d\udea8","text":"It is strongly recommended to read this section before using django-components in production.
"},{"location":"overview/security_notes/#static-files","title":"Static files","text":"TL;DR: No action needed from v0.100 onwards. Before v0.100, use
safer_staticfiles
to avoid exposing backend logic.Components can be organized however you prefer. That said, our prefered way is to keep the files of a component close together by bundling them in the same directory.
This means that files containing backend logic, such as Python modules and HTML templates, live in the same directory as static files, e.g. JS and CSS.
From v0.100 onwards, we keep component files (as defined by
COMPONENTS.dirs
andCOMPONENTS.app_dirs
) separate from the rest of the static files (defined bySTATICFILES_DIRS
). That way, the Python and HTML files are NOT exposed by the server. Only the static JS, CSS, and other common formats.Note
If you need to expose different file formats, you can configure these with
"},{"location":"overview/security_notes/#static-files-prior-to-v0100","title":"Static files prior to v0.100","text":"COMPONENTS.static_files_allowed
andCOMPONENTS.static_files_forbidden
.Prior to v0.100, if your were using django.contrib.staticfiles to collect static files, no distinction was made between the different kinds of files.
As a result, your Python code and templates may inadvertently become available on your static file server. You probably don't want this, as parts of your backend logic will be exposed, posing a potential security vulnerability.
From v0.27 until v0.100, django-components shipped with an additional installable app django_components.safer_staticfiles. It was a drop-in replacement for django.contrib.staticfiles. Its behavior is 100% identical except it ignores
.py
and.html
files, meaning these will not end up on your static files server.To use it, add it to
INSTALLED_APPS
and remove django.contrib.staticfiles.INSTALLED_APPS = [\n # 'django.contrib.staticfiles', # <-- REMOVE\n 'django_components',\n 'django_components.safer_staticfiles' # <-- ADD\n]\n
If you are on an pre-v0.27 version of django-components, your alternatives are:
- a) passing
--ignore <pattern>
options to the collecstatic CLI command, - b) defining a subclass of StaticFilesConfig.
Both routes are described in the official docs of the staticfiles app.
Note that
safer_staticfiles
excludes the.py
and.html
files for collectstatic command:python manage.py collectstatic\n
but it is ignored on the development server:
python manage.py runserver\n
For a step-by-step guide on deploying production server with static files, see the demo project.
See the older versions of the sampleproject for a setup with pre-v0.100 version.
"},{"location":"overview/welcome/","title":"Welcome to Django Components","text":"django-components
combines Django's templating system with the modularity seen in modern frontend frameworks like Vue or React.With
"},{"location":"overview/welcome/#quickstart","title":"Quickstart","text":"django-components
you can support Django projects small and large without leaving the Django ecosystem.A component in django-components can be as simple as a Django template and Python code to declare the component:
components/calendar/calendar.html
components/calendar/calendar.py<div class=\"calendar\">\n Today's date is <span>{{ date }}</span>\n</div>\n
from django_components import Component\n\nclass Calendar(Component):\n template_file = \"calendar.html\"\n
Or a combination of Django template, Python, CSS, and Javascript:
components/calendar/calendar.html
components/calendar/calendar.css<div class=\"calendar\">\n Today's date is <span>{{ date }}</span>\n</div>\n
components/calendar/calendar.js.calendar {\n width: 200px;\n background: pink;\n}\n
components/calendar/calendar.pydocument.querySelector(\".calendar\").onclick = function () {\n alert(\"Clicked calendar!\");\n};\n
from django_components import Component\n\nclass Calendar(Component):\n template_file = \"calendar.html\"\n js_file = \"calendar.js\"\n css_file = \"calendar.css\"\n\n def get_context_data(self, date):\n return {\"date\": date}\n
Use the component like this:
{% component \"calendar\" date=\"2024-11-06\" %}{% endcomponent %}\n
And this is what gets rendered:
<div class=\"calendar-component\">\n Today's date is <span>2024-11-06</span>\n</div>\n
Read on to learn about all the exciting details and configuration possibilities!
(If you instead prefer to jump right into the code, check out the example project)
"},{"location":"overview/welcome/#features","title":"Features","text":""},{"location":"overview/welcome/#modern-and-modular-ui","title":"Modern and modular UI","text":"- Create self-contained, reusable UI elements.
- Each component can include its own HTML, CSS, and JS, or additional third-party JS and CSS.
- HTML, CSS, and JS can be defined on the component class, or loaded from files.
"},{"location":"overview/welcome/#composition-with-slots","title":"Composition with slots","text":"from django_components import Component\n\n@register(\"calendar\")\nclass Calendar(Component):\n template = \"\"\"\n <div class=\"calendar\">\n Today's date is\n <span>{{ date }}</span>\n </div>\n \"\"\"\n\n css = \"\"\"\n .calendar {\n width: 200px;\n background: pink;\n }\n \"\"\"\n\n js = \"\"\"\n document.querySelector(\".calendar\")\n .addEventListener(\"click\", () => {\n alert(\"Clicked calendar!\");\n });\n \"\"\"\n\n # Additional JS and CSS\n class Media:\n js = [\"https://cdn.jsdelivr.net/npm/htmx.org@2.1.1/dist/htmx.min.js\"]\n css = [\"bootstrap/dist/css/bootstrap.min.css\"]\n\n # Variables available in the template\n def get_context_data(self, date):\n return {\n \"date\": date\n }\n
- Render components inside templates with
{% component %}
tag. - Compose them with
{% slot %}
and{% fill %}
tags. - Vue-like slot system, including scoped slots.
"},{"location":"overview/welcome/#extended-template-tags","title":"Extended template tags","text":"{% component \"Layout\"\n bookmarks=bookmarks\n breadcrumbs=breadcrumbs\n%}\n {% fill \"header\" %}\n <div class=\"flex justify-between gap-x-12\">\n <div class=\"prose\">\n <h3>{{ project.name }}</h3>\n </div>\n <div class=\"font-semibold text-gray-500\">\n {{ project.start_date }} - {{ project.end_date }}\n </div>\n </div>\n {% endfill %}\n\n {# Access data passed to `{% slot %}` with `data` #}\n {% fill \"tabs\" data=\"tabs_data\" %}\n {% component \"TabItem\" header=\"Project Info\" %}\n {% component \"ProjectInfo\"\n project=project\n project_tags=project_tags\n attrs:class=\"py-5\"\n attrs:width=tabs_data.width\n / %}\n {% endcomponent %}\n {% endfill %}\n{% endcomponent %}\n
django-components
extends Django's template tags syntax with:- Literal lists and dictionaries in template tags
- Self-closing tags
{% mytag / %}
- Multi-line template tags
- Spread operator
...
to dynamically pass args or kwargs into the template tag - Nested template tags like
\"{{ first_name }} {{ last_name }}\"
- Flat definition of dictionary keys
attr:key=val
"},{"location":"overview/welcome/#html-fragment-support","title":"HTML fragment support","text":"{% component \"table\"\n ...default_attrs\n title=\"Friend list for {{ user.name }}\"\n headers=[\"Name\", \"Age\", \"Email\"]\n data=[\n {\n \"name\": \"John\"|upper,\n \"age\": 30|add:1,\n \"email\": \"john@example.com\",\n \"hobbies\": [\"reading\"],\n },\n {\n \"name\": \"Jane\"|upper,\n \"age\": 25|add:1,\n \"email\": \"jane@example.com\",\n \"hobbies\": [\"reading\", \"coding\"],\n },\n ],\n attrs:class=\"py-4 ma-2 border-2 border-gray-300 rounded-md\"\n/ %}\n
django-components
makes intergration with HTMX, AlpineJS or jQuery easy by allowing components to be rendered as HTML fragments:-
Components's JS and CSS is loaded automatically when the fragment is inserted into the DOM
-
Expose components as views with
get
,post
,put
,patch
,delete
methods
"},{"location":"overview/welcome/#type-hints","title":"Type hints","text":"# components/calendar/calendar.py\n@register(\"calendar\")\nclass Calendar(Component):\n template_file = \"calendar.html\"\n\n def get(self, request, *args, **kwargs):\n page = request.GET.get(\"page\", 1)\n return self.render_to_response(\n kwargs={\n \"page\": page,\n }\n )\n\n def get_context_data(self, page):\n return {\n \"page\": page,\n }\n\n# urls.py\npath(\"calendar/\", Calendar.as_view()),\n
Opt-in to type hints by defining types for component's args, kwargs, slots, and more:
from typing import NotRequired, Tuple, TypedDict, SlotContent, SlotFunc\n\nButtonArgs = Tuple[int, str]\n\nclass ButtonKwargs(TypedDict):\n variable: str\n another: int\n maybe_var: NotRequired[int] # May be omitted\n\nclass ButtonData(TypedDict):\n variable: str\n\nclass ButtonSlots(TypedDict):\n my_slot: NotRequired[SlotFunc]\n another_slot: SlotContent\n\nButtonType = Component[ButtonArgs, ButtonKwargs, ButtonSlots, ButtonData, JsData, CssData]\n\nclass Button(ButtonType):\n def get_context_data(self, *args, **kwargs):\n self.input.args[0] # int\n self.input.kwargs[\"variable\"] # str\n self.input.slots[\"my_slot\"] # SlotFunc[MySlotData]\n\n return {} # Error: Key \"variable\" is missing\n
When you then call
Button.render()
orButton.render_to_response()
, you will get type hints:
"},{"location":"overview/welcome/#debugging-features","title":"Debugging features","text":"Button.render(\n # Error: First arg must be `int`, got `float`\n args=(1.25, \"abc\"),\n # Error: Key \"another\" is missing\n kwargs={\n \"variable\": \"text\",\n },\n)\n
- Visual component inspection: Highlight components and slots directly in your browser.
- Detailed tracing logs to supply AI-agents with context: The logs include component and slot names and IDs, and their position in the tree.
- Install and use third-party components from PyPI
- Or publish your own \"component registry\"
-
Highly customizable - Choose how the components are called in the template (and more):
{% component \"calendar\" date=\"2024-11-06\" %}\n{% endcomponent %}\n\n{% calendar date=\"2024-11-06\" %}\n{% endcalendar %}\n
- Vue-like provide / inject system
- Format HTML attributes with
{% html_attrs %}
Read the Release Notes to see the latest features and fixes.
"},{"location":"overview/welcome/#community-examples","title":"Community examples","text":"One of our goals with
"},{"location":"overview/welcome/#contributing-and-development","title":"Contributing and development","text":"django-components
is to make it easy to share components between projects. Head over to the Community examples to see some examples.Get involved or sponsor this project - See here
Running django-components locally for development - See here
"},{"location":"reference/api/","title":"Api","text":""},{"location":"reference/api/#api","title":"API","text":""},{"location":"reference/api/#django_components.BaseNode","title":"BaseNode","text":"BaseNode(\n params: List[TagAttr], flags: Optional[Dict[str, bool]] = None, nodelist: Optional[NodeList] = None, node_id: Optional[str] = None\n)\n
Bases:
django.template.base.Node
See source code
Node class for all django-components custom template tags.
This class has a dual role:
-
It declares how a particular template tag should be parsed - By setting the
tag
,end_tag
, andallowed_flags
attributes:class SlotNode(BaseNode):\n tag = \"slot\"\n end_tag = \"endslot\"\n allowed_flags = [\"required\"]\n
This will allow the template tag
{% slot %}
to be used like this:{% slot required %} ... {% endslot %}\n
-
The
render
method is the actual implementation of the template tag.This is where the tag's logic is implemented:
class MyNode(BaseNode):\n tag = \"mynode\"\n\n def render(self, context: Context, name: str, **kwargs: Any) -> str:\n return f\"Hello, {name}!\"\n
This will allow the template tag
{% mynode %}
to be used like this:{% mynode name=\"John\" %}\n
The template tag accepts parameters as defined on the
render
method's signature.For more info, see
BaseNode.render()
.Methods:
-
parse
\u2013 -
register
\u2013 -
render
\u2013 -
unregister
\u2013
Attributes:
-
active_flags
(List[str]
) \u2013 -
allowed_flags
(Optional[List[str]]
) \u2013 -
end_tag
(Optional[str]
) \u2013 -
flags
\u2013 -
node_id
\u2013 -
nodelist
\u2013 -
params
\u2013 -
tag
(str
) \u2013
property
","text":"active_flags: List[str]\n
See source code
Flags that were set for this specific instance.
"},{"location":"reference/api/#django_components.BaseNode.allowed_flags","title":"allowed_flagsclass-attribute
instance-attribute
","text":"allowed_flags: Optional[List[str]] = None\n
See source code
The allowed flags for this tag.
E.g.
"},{"location":"reference/api/#django_components.BaseNode.end_tag","title":"end_tag[\"required\"]
will allow this tag to be used like{% slot required %}
.class-attribute
instance-attribute
","text":"end_tag: Optional[str] = None\n
See source code
The end tag name.
E.g.
\"endcomponent\"
or\"endslot\"
will make this class match template tags{% endcomponent %}
or{% endslot %}
.If not set, then this template tag has no end tag.
So instead of
"},{"location":"reference/api/#django_components.BaseNode.flags","title":"flags{% component %} ... {% endcomponent %}
, you'd use only{% component %}
.instance-attribute
","text":"
"},{"location":"reference/api/#django_components.BaseNode.node_id","title":"node_idflags = flags or {flag: Falsefor flag in allowed_flags or []}\n
instance-attribute
","text":"
"},{"location":"reference/api/#django_components.BaseNode.nodelist","title":"nodelistnode_id = node_id or gen_id()\n
instance-attribute
","text":"
"},{"location":"reference/api/#django_components.BaseNode.params","title":"paramsnodelist = nodelist or NodeList()\n
instance-attribute
","text":"
"},{"location":"reference/api/#django_components.BaseNode.tag","title":"tagparams = params\n
instance-attribute
","text":"tag: str\n
See source code
The tag name.
E.g.
"},{"location":"reference/api/#django_components.BaseNode.parse","title":"parse\"component\"
or\"slot\"
will make this class match template tags{% component %}
or{% slot %}
.classmethod
","text":"parse(parser: Parser, token: Token, **kwargs: Any) -> BaseNode\n
See source code
This function is what is passed to Django's
Library.tag()
when registering the tag.In other words, this method is called by Django's template parser when we encounter a tag that matches this node's tag, e.g.
{% component %}
or{% slot %}
.To register the tag, you can use
"},{"location":"reference/api/#django_components.BaseNode.register","title":"registerBaseNode.register()
.classmethod
","text":"register(library: Library) -> None\n
See source code
A convenience method for registering the tag with the given library.
class MyNode(BaseNode):\n tag = \"mynode\"\n\nMyNode.register(library)\n
Allows you to then use the node in templates like so:
"},{"location":"reference/api/#django_components.BaseNode.render","title":"render","text":"{% load mylibrary %}\n{% mynode %}\n
render(context: Context, *args: Any, **kwargs: Any) -> str\n
See source code
Render the node. This method is meant to be overridden by subclasses.
The signature of this function decides what input the template tag accepts.
The
render()
method MUST accept acontext
argument. Any arguments after that will be part of the tag's input parameters.So if you define a
render
method like this:def render(self, context: Context, name: str, **kwargs: Any) -> str:\n
Then the tag will require the
name
parameter, and accept any extra keyword arguments:
"},{"location":"reference/api/#django_components.BaseNode.unregister","title":"unregister{% component name=\"John\" age=20 %}\n
classmethod
","text":"unregister(library: Library) -> None\n
See source code
Unregisters the node from the given library.
"},{"location":"reference/api/#django_components.Component","title":"Component","text":"Component(registered_name: Optional[str] = None, outer_context: Optional[Context] = None, registry: Optional[ComponentRegistry] = None)\n
Methods:
-
as_view
\u2013 -
get_context_data
\u2013 -
get_template
\u2013 -
get_template_name
\u2013 -
inject
\u2013 -
on_render_after
\u2013 -
on_render_before
\u2013 -
render
\u2013 -
render_to_response
\u2013
Attributes:
-
Media
(Optional[Type[ComponentMediaInput]]
) \u2013 -
View
\u2013 -
css
(Optional[str]
) \u2013 -
css_file
(Optional[str]
) \u2013 -
id
(str
) \u2013 -
input
(RenderInput[ArgsType, KwargsType, SlotsType]
) \u2013 -
is_filled
(SlotIsFilled
) \u2013 -
js
(Optional[str]
) \u2013 -
js_file
(Optional[str]
) \u2013 -
media
(Optional[Media]
) \u2013 -
media_class
(Type[Media]
) \u2013 -
name
(str
) \u2013 -
outer_context
(Optional[Context]
) \u2013 -
registered_name
(Optional[str]
) \u2013 -
registry
\u2013 -
response_class
\u2013 -
template
(Optional[Union[str, Template]]
) \u2013 -
template_file
(Optional[str]
) \u2013 -
template_name
(Optional[str]
) \u2013
class-attribute
instance-attribute
","text":"Media: Optional[Type[ComponentMediaInput]] = None\n
See source code
Defines JS and CSS media files associated with this component.
This
Media
class behaves similarly to Django's Media class:- Paths are generally handled as static file paths, and resolved URLs are rendered to HTML with
media_class.render_js()
ormedia_class.render_css()
. - A path that starts with
http
,https
, or/
is considered a URL, skipping the static file resolution. This path is still rendered to HTML withmedia_class.render_js()
ormedia_class.render_css()
. - A
SafeString
(with__html__
method) is considered an already-formatted HTML tag, skipping both static file resolution and rendering withmedia_class.render_js()
ormedia_class.render_css()
. - You can set
extend
to configure whether to inherit JS / CSS from parent components. See Controlling Media Inheritance.
However, there's a few differences from Django's Media class:
- Our Media class accepts various formats for the JS and CSS files: either a single file, a list, or (CSS-only) a dictionary (See
ComponentMediaInput
). - Individual JS / CSS files can be any of
str
,bytes
,Path
,SafeString
, or a function (SeeComponentMediaInputPath
).
Example:
"},{"location":"reference/api/#django_components.Component.View","title":"Viewclass MyTable(Component):\n class Media:\n js = [\n \"path/to/script.js\",\n \"https://unpkg.com/alpinejs@3.14.7/dist/cdn.min.js\", # AlpineJS\n ]\n css = {\n \"all\": [\n \"path/to/style.css\",\n \"https://unpkg.com/tailwindcss@^2/dist/tailwind.min.css\", # TailwindCSS\n ],\n \"print\": [\"path/to/style2.css\"],\n }\n
class-attribute
instance-attribute
","text":"
"},{"location":"reference/api/#django_components.Component.css","title":"cssView = ComponentView\n
class-attribute
instance-attribute
","text":"css: Optional[str] = None\n
See source code
Main CSS associated with this component inlined as string.
Only one of
css
orcss_file
must be defined.Example:
"},{"location":"reference/api/#django_components.Component.css_file","title":"css_fileclass MyComponent(Component):\n css = \"\"\"\n .my-class {\n color: red;\n }\n \"\"\"\n
class-attribute
instance-attribute
","text":"css_file: Optional[str] = None\n
See source code
Main CSS associated with this component as file path.
The filepath must be either:
- Relative to the directory where the Component's Python file is defined.
- Relative to one of the component directories, as set by
COMPONENTS.dirs
orCOMPONENTS.app_dirs
(e.g.<root>/components/
). - Relative to the staticfiles directories, as set by Django's
STATICFILES_DIRS
setting (e.g.<root>/static/
).
When you create a Component class with
css_file
, these will happen:- If the file path is relative to the directory where the component's Python file is, the path is resolved.
- The file is read and its contents is set to
Component.css
.
Only one of
css
orcss_file
must be defined.Example:
path/to/style.css
path/to/component.py.my-class {\n color: red;\n}\n
"},{"location":"reference/api/#django_components.Component.id","title":"idclass MyComponent(Component):\n css_file = \"path/to/style.css\"\n\nprint(MyComponent.css)\n# Output:\n# .my-class {\n# color: red;\n# };\n
property
","text":"id: str\n
See source code
This ID is unique for every time a
Component.render()
(or equivalent) is called (AKA \"render ID\").This is useful for logging or debugging.
Raises
RuntimeError
if accessed outside of rendering execution.A single render ID has a chance of collision 1 in 3.3M. However, due to birthday paradox, the chance of collision increases when approaching ~1,000 render IDs.
Thus, there is a soft-cap of 1,000 components rendered on a single page.
If you need to more than that, please open an issue on GitHub.
Example:
"},{"location":"reference/api/#django_components.Component.input","title":"inputclass MyComponent(Component):\n def get_context_data(self):\n print(f\"Rendering '{self.id}'\")\n return {}\n\nMyComponent.render()\n# Rendering 'ab3c4d'\n
property
","text":"input: RenderInput[ArgsType, KwargsType, SlotsType]\n
See source code
Input holds the data (like arg, kwargs, slots) that were passed to the current execution of the
"},{"location":"reference/api/#django_components.Component.is_filled","title":"is_filledrender
method.property
","text":"is_filled: SlotIsFilled\n
See source code
Dictionary describing which slots have or have not been filled.
This attribute is available for use only within the template as
"},{"location":"reference/api/#django_components.Component.js","title":"js{{ component_vars.is_filled.slot_name }}
, and withinon_render_before
andon_render_after
hooks.class-attribute
instance-attribute
","text":"js: Optional[str] = None\n
See source code
Main JS associated with this component inlined as string.
Only one of
js
orjs_file
must be defined.Example:
"},{"location":"reference/api/#django_components.Component.js_file","title":"js_fileclass MyComponent(Component):\n js = \"console.log('Hello, World!');\"\n
class-attribute
instance-attribute
","text":"js_file: Optional[str] = None\n
See source code
Main JS associated with this component as file path.
The filepath must be either:
- Relative to the directory where the Component's Python file is defined.
- Relative to one of the component directories, as set by
COMPONENTS.dirs
orCOMPONENTS.app_dirs
(e.g.<root>/components/
). - Relative to the staticfiles directories, as set by Django's
STATICFILES_DIRS
setting (e.g.<root>/static/
).
When you create a Component class with
js_file
, these will happen:- If the file path is relative to the directory where the component's Python file is, the path is resolved.
- The file is read and its contents is set to
Component.js
.
Only one of
js
orjs_file
must be defined.Example:
path/to/script.js
path/to/component.pyconsole.log('Hello, World!');\n
"},{"location":"reference/api/#django_components.Component.media","title":"mediaclass MyComponent(Component):\n js_file = \"path/to/script.js\"\n\nprint(MyComponent.js)\n# Output: console.log('Hello, World!');\n
class-attribute
instance-attribute
","text":"media: Optional[Media] = None\n
See source code
Normalized definition of JS and CSS media files associated with this component.
None
ifComponent.Media
is not defined.This field is generated from
Component.media_class
.Read more on Accessing component's HTML / JS / CSS.
Example:
"},{"location":"reference/api/#django_components.Component.media_class","title":"media_classclass MyComponent(Component):\n class Media:\n js = \"path/to/script.js\"\n css = \"path/to/style.css\"\n\nprint(MyComponent.media)\n# Output:\n# <script src=\"/static/path/to/script.js\"></script>\n# <link href=\"/static/path/to/style.css\" media=\"all\" rel=\"stylesheet\">\n
class-attribute
instance-attribute
","text":"media_class: Type[Media] = Media\n
See source code
Set the Media class that will be instantiated with the JS and CSS media files from
Component.Media
.This is useful when you want to customize the behavior of the media files, like customizing how the JS or CSS files are rendered into
<script>
or<link>
HTML tags. Read more in Defining HTML / JS / CSS files.Example:
"},{"location":"reference/api/#django_components.Component.name","title":"nameclass MyTable(Component):\n class Media:\n js = \"path/to/script.js\"\n css = \"path/to/style.css\"\n\n media_class = MyMediaClass\n
property
","text":"
"},{"location":"reference/api/#django_components.Component.outer_context","title":"outer_contextname: str\n
instance-attribute
","text":"
"},{"location":"reference/api/#django_components.Component.registered_name","title":"registered_nameouter_context: Optional[Context] = outer_context\n
instance-attribute
","text":"
"},{"location":"reference/api/#django_components.Component.registry","title":"registryregistered_name: Optional[str] = registered_name\n
instance-attribute
","text":"
"},{"location":"reference/api/#django_components.Component.response_class","title":"response_classregistry = registry or registry\n
class-attribute
instance-attribute
","text":"response_class = HttpResponse\n
See source code
This allows to configure what class is used to generate response from
"},{"location":"reference/api/#django_components.Component.template","title":"templaterender_to_response
class-attribute
instance-attribute
","text":"template: Optional[Union[str, Template]] = None\n
See source code
Inlined Django template associated with this component. Can be a plain string or a Template instance.
Only one of
template_file
,get_template_name
,template
orget_template
must be defined.Example:
"},{"location":"reference/api/#django_components.Component.template_file","title":"template_fileclass MyComponent(Component):\n template = \"Hello, {{ name }}!\"\n\n def get_context_data(self):\n return {\"name\": \"World\"}\n
class-attribute
instance-attribute
","text":"template_file: Optional[str] = None\n
See source code
Filepath to the Django template associated with this component.
The filepath must be either:
- Relative to the directory where the Component's Python file is defined.
- Relative to one of the component directories, as set by
COMPONENTS.dirs
orCOMPONENTS.app_dirs
(e.g.<root>/components/
). - Relative to the template directories, as set by Django's
TEMPLATES
setting (e.g.<root>/templates/
).
Only one of
template_file
,get_template_name
,template
orget_template
must be defined.Example:
"},{"location":"reference/api/#django_components.Component.template_name","title":"template_nameclass MyComponent(Component):\n template_file = \"path/to/template.html\"\n\n def get_context_data(self):\n return {\"name\": \"World\"}\n
instance-attribute
","text":"template_name: Optional[str]\n
See source code
Alias for
template_file
.For historical reasons, django-components used
template_name
to align with Django's TemplateView.template_file
was introduced to align withjs/js_file
andcss/css_file
.Setting and accessing this attribute is proxied to
"},{"location":"reference/api/#django_components.Component.as_view","title":"as_viewtemplate_file
.classmethod
","text":"as_view(**initkwargs: Any) -> ViewFn\n
See source code
Shortcut for calling
"},{"location":"reference/api/#django_components.Component.get_context_data","title":"get_context_data","text":"Component.View.as_view
and passing component instance to it.
"},{"location":"reference/api/#django_components.Component.get_template","title":"get_template","text":"get_context_data(*args: Any, **kwargs: Any) -> DataType\n
get_template(context: Context) -> Optional[Union[str, Template]]\n
See source code
Inlined Django template associated with this component. Can be a plain string or a Template instance.
Only one of
"},{"location":"reference/api/#django_components.Component.get_template_name","title":"get_template_name","text":"template_file
,get_template_name
,template
orget_template
must be defined.get_template_name(context: Context) -> Optional[str]\n
See source code
Filepath to the Django template associated with this component.
The filepath must be relative to either the file where the component class was defined, or one of the roots of
STATIFILES_DIRS
.Only one of
"},{"location":"reference/api/#django_components.Component.inject","title":"inject","text":"template_file
,get_template_name
,template
orget_template
must be defined.inject(key: str, default: Optional[Any] = None) -> Any\n
See source code
Use this method to retrieve the data that was passed to a
{% provide %}
tag with the corresponding key.To retrieve the data,
inject()
must be called inside a component that's inside the{% provide %}
tag.You may also pass a default that will be used if the
provide
tag with given key was NOT found.This method mut be used inside the
get_context_data()
method and raises an error if called elsewhere.Example:
Given this template:
{% provide \"provider\" hello=\"world\" %}\n {% component \"my_comp\" %}\n {% endcomponent %}\n{% endprovide %}\n
And given this definition of \"my_comp\" component:
from django_components import Component, register\n\n@register(\"my_comp\")\nclass MyComp(Component):\n template = \"hi {{ data.hello }}!\"\n def get_context_data(self):\n data = self.inject(\"provider\")\n return {\"data\": data}\n
This renders into:
hi world!\n
As the
"},{"location":"reference/api/#django_components.Component.on_render_after","title":"on_render_after","text":"{{ data.hello }}
is taken from the \"provider\".on_render_after(context: Context, template: Template, content: str) -> Optional[SlotResult]\n
See source code
Hook that runs just after the component's template was rendered. It receives the rendered output as the last argument.
You can use this hook to access the context or the template, but modifying them won't have any effect.
To override the content that gets rendered, you can return a string or SafeString from this hook.
"},{"location":"reference/api/#django_components.Component.on_render_before","title":"on_render_before","text":"on_render_before(context: Context, template: Template) -> None\n
See source code
Hook that runs just before the component's template is rendered.
You can use this hook to access or modify the context or the template.
"},{"location":"reference/api/#django_components.Component.render","title":"renderclassmethod
","text":"render(\n context: Optional[Union[Dict[str, Any], Context]] = None,\n args: Optional[ArgsType] = None,\n kwargs: Optional[KwargsType] = None,\n slots: Optional[SlotsType] = None,\n escape_slots_content: bool = True,\n type: RenderType = \"document\",\n render_dependencies: bool = True,\n request: Optional[HttpRequest] = None,\n) -> str\n
See source code
Render the component into a string.
Inputs: -
args
- Positional args for the component. This is the same as calling the component as{% component \"my_comp\" arg1 arg2 ... %}
-kwargs
- Kwargs for the component. This is the same as calling the component as{% component \"my_comp\" key1=val1 key2=val2 ... %}
-slots
- Component slot fills. This is the same as pasing{% fill %}
tags to the component. Accepts a dictionary of{ slot_name: slot_content }
whereslot_content
can be a string or render function. -escape_slots_content
- Whether the content fromslots
should be escaped. -context
- A context (dictionary or Django's Context) within which the component is rendered. The keys on the context can be accessed from within the template. - NOTE: In \"isolated\" mode, context is NOT accessible, and data MUST be passed via component's args and kwargs. -type
- Configure how to handle JS and CSS dependencies. -\"document\"
(default) - JS dependencies are inserted into{% component_js_dependencies %}
, or to the end of the<body>
tag. CSS dependencies are inserted into{% component_css_dependencies %}
, or the end of the<head>
tag. -render_dependencies
- Set this toFalse
if you want to insert the resulting HTML into another component. -request
- The request object. This is only required when needing to use RequestContext, e.g. to enable templatecontext_processors
. Unused if context is already an instance ofContext
Example:
"},{"location":"reference/api/#django_components.Component.render_to_response","title":"render_to_responseMyComponent.render(\n args=[1, \"two\", {}],\n kwargs={\n \"key\": 123,\n },\n slots={\n \"header\": 'STATIC TEXT HERE',\n \"footer\": lambda ctx, slot_kwargs, slot_ref: f'CTX: {ctx['hello']} SLOT_DATA: {slot_kwargs['abc']}',\n },\n escape_slots_content=False,\n)\n
classmethod
","text":"render_to_response(\n context: Optional[Union[Dict[str, Any], Context]] = None,\n slots: Optional[SlotsType] = None,\n escape_slots_content: bool = True,\n args: Optional[ArgsType] = None,\n kwargs: Optional[KwargsType] = None,\n type: RenderType = \"document\",\n request: Optional[HttpRequest] = None,\n *response_args: Any,\n **response_kwargs: Any\n) -> HttpResponse\n
See source code
Render the component and wrap the content in the response class.
The response class is taken from
Component.response_class
. Defaults todjango.http.HttpResponse
.This is the interface for the
django.views.View
class which allows us to use components as Django views withcomponent.as_view()
.Inputs: -
args
- Positional args for the component. This is the same as calling the component as{% component \"my_comp\" arg1 arg2 ... %}
-kwargs
- Kwargs for the component. This is the same as calling the component as{% component \"my_comp\" key1=val1 key2=val2 ... %}
-slots
- Component slot fills. This is the same as pasing{% fill %}
tags to the component. Accepts a dictionary of{ slot_name: slot_content }
whereslot_content
can be a string or render function. -escape_slots_content
- Whether the content fromslots
should be escaped. -context
- A context (dictionary or Django's Context) within which the component is rendered. The keys on the context can be accessed from within the template. - NOTE: In \"isolated\" mode, context is NOT accessible, and data MUST be passed via component's args and kwargs. -type
- Configure how to handle JS and CSS dependencies. -\"document\"
(default) - JS dependencies are inserted into{% component_js_dependencies %}
, or to the end of the<body>
tag. CSS dependencies are inserted into{% component_css_dependencies %}
, or the end of the<head>
tag. -request
- The request object. This is only required when needing to use RequestContext, e.g. to enable templatecontext_processors
. Unused if context is already an instance ofContext
Any additional args and kwargs are passed to the
response_class
.Example:
"},{"location":"reference/api/#django_components.ComponentFileEntry","title":"ComponentFileEntry","text":"MyComponent.render_to_response(\n args=[1, \"two\", {}],\n kwargs={\n \"key\": 123,\n },\n slots={\n \"header\": 'STATIC TEXT HERE',\n \"footer\": lambda ctx, slot_kwargs, slot_ref: f'CTX: {ctx['hello']} SLOT_DATA: {slot_kwargs['abc']}',\n },\n escape_slots_content=False,\n # HttpResponse input\n status=201,\n headers={...},\n)\n# HttpResponse(content=..., status=201, headers=...)\n
Bases:
tuple
See source code
Result returned by
get_component_files()
.Attributes:
-
dot_path
(str
) \u2013 -
filepath
(Path
) \u2013
instance-attribute
","text":"dot_path: str\n
See source code
The python import path for the module. E.g.
"},{"location":"reference/api/#django_components.ComponentFileEntry.filepath","title":"filepathapp.components.mycomp
instance-attribute
","text":"filepath: Path\n
See source code
The filesystem path to the module. E.g.
"},{"location":"reference/api/#django_components.ComponentMediaInput","title":"ComponentMediaInput","text":"/path/to/project/app/components/mycomp.py
Bases:
typing.Protocol
See source code
Defines JS and CSS media files associated with a
Component
.class MyTable(Component):\n class Media:\n js = [\n \"path/to/script.js\",\n \"https://unpkg.com/alpinejs@3.14.7/dist/cdn.min.js\", # AlpineJS\n ]\n css = {\n \"all\": [\n \"path/to/style.css\",\n \"https://unpkg.com/tailwindcss@^2/dist/tailwind.min.css\", # TailwindCSS\n ],\n \"print\": [\"path/to/style2.css\"],\n }\n
Attributes:
-
css
(Optional[Union[ComponentMediaInputPath, List[ComponentMediaInputPath], Dict[str, ComponentMediaInputPath], Dict[str, List[ComponentMediaInputPath]]]]
) \u2013 -
extend
(Union[bool, List[Type[Component]]]
) \u2013 -
js
(Optional[Union[ComponentMediaInputPath, List[ComponentMediaInputPath]]]
) \u2013
class-attribute
instance-attribute
","text":"css: Optional[\n Union[\n ComponentMediaInputPath, List[ComponentMediaInputPath], Dict[str, ComponentMediaInputPath], Dict[str, List[ComponentMediaInputPath]]\n ]\n] = None\n
See source code
CSS files associated with a
Component
.-
If a string, it's assumed to be a path to a CSS file.
-
If a list, each entry is assumed to be a path to a CSS file.
-
If a dict, the keys are media types (e.g. \"all\", \"print\", \"screen\", etc.), and the values are either:
- A string, assumed to be a path to a CSS file.
- A list, each entry is assumed to be a path to a CSS file.
Each entry can be a string, bytes, SafeString, PathLike, or a callable that returns one of the former (see
ComponentMediaInputPath
).Examples:
class MyComponent(Component):\n class Media:\n css = \"path/to/style.css\"\n
class MyComponent(Component):\n class Media:\n css = [\"path/to/style1.css\", \"path/to/style2.css\"]\n
class MyComponent(Component):\n class Media:\n css = {\n \"all\": \"path/to/style.css\",\n \"print\": \"path/to/print.css\",\n }\n
"},{"location":"reference/api/#django_components.ComponentMediaInput.extend","title":"extendclass MyComponent(Component):\n class Media:\n css = {\n \"all\": [\"path/to/style1.css\", \"path/to/style2.css\"],\n \"print\": \"path/to/print.css\",\n }\n
class-attribute
instance-attribute
","text":"extend: Union[bool, List[Type[Component]]] = True\n
See source code
Configures whether the component should inherit the media files from the parent component.
- If
True
, the component inherits the media files from the parent component. - If
False
, the component does not inherit the media files from the parent component. - If a list of components classes, the component inherits the media files ONLY from these specified components.
Read more in Controlling Media Inheritance section.
Example:
Disable media inheritance:
class ParentComponent(Component):\n class Media:\n js = [\"parent.js\"]\n\nclass MyComponent(ParentComponent):\n class Media:\n extend = False # Don't inherit parent media\n js = [\"script.js\"]\n\nprint(MyComponent.media._js) # [\"script.js\"]\n
Specify which components to inherit from. In this case, the media files are inherited ONLY from the specified components, and NOT from the original parent components:
"},{"location":"reference/api/#django_components.ComponentMediaInput.js","title":"jsclass ParentComponent(Component):\n class Media:\n js = [\"parent.js\"]\n\nclass MyComponent(ParentComponent):\n class Media:\n # Only inherit from these, ignoring the files from the parent\n extend = [OtherComponent1, OtherComponent2]\n\n js = [\"script.js\"]\n\nprint(MyComponent.media._js) # [\"script.js\", \"other1.js\", \"other2.js\"]\n
class-attribute
instance-attribute
","text":"js: Optional[Union[ComponentMediaInputPath, List[ComponentMediaInputPath]]] = None\n
See source code
JS files associated with a
Component
.-
If a string, it's assumed to be a path to a JS file.
-
If a list, each entry is assumed to be a path to a JS file.
Each entry can be a string, bytes, SafeString, PathLike, or a callable that returns one of the former (see
ComponentMediaInputPath
).Examples:
class MyComponent(Component):\n class Media:\n js = \"path/to/script.js\"\n
class MyComponent(Component):\n class Media:\n js = [\"path/to/script1.js\", \"path/to/script2.js\"]\n
"},{"location":"reference/api/#django_components.ComponentMediaInputPath","title":"ComponentMediaInputPathclass MyComponent(Component):\n class Media:\n js = lambda: [\"path/to/script1.js\", \"path/to/script2.js\"]\n
module-attribute
","text":"ComponentMediaInputPath = Union[str, bytes, SafeData, Path, PathLike, Callable[[], Union[str, bytes, SafeData, Path, PathLike]]]\n
See source code
A type representing an entry in Media.js or Media.css.
If an entry is a SafeString (or has
__html__
method), then entry is assumed to be a formatted HTML tag. Otherwise, it's assumed to be a path to a file.Example:
"},{"location":"reference/api/#django_components.ComponentRegistry","title":"ComponentRegistry","text":"class MyComponent\n class Media:\n js = [\n \"path/to/script.js\",\n b\"script.js\",\n SafeString(\"<script src='path/to/script.js'></script>\"),\n ]\n css = [\n Path(\"path/to/style.css\"),\n lambda: \"path/to/style.css\",\n lambda: Path(\"path/to/style.css\"),\n ]\n
ComponentRegistry(\n library: Optional[Library] = None, settings: Optional[Union[RegistrySettings, Callable[[ComponentRegistry], RegistrySettings]]] = None\n)\n
Bases:
object
See source code
Manages components and makes them available in the template, by default as
{% component %}
tags.{% component \"my_comp\" key=value %}\n{% endcomponent %}\n
To enable a component to be used in a template, the component must be registered with a component registry.
When you register a component to a registry, behind the scenes the registry automatically adds the component's template tag (e.g.
{% component %}
to theLibrary
. And the opposite happens when you unregister a component - the tag is removed.See Registering components.
Parameters:
-
library
(Library
, default:None
) \u2013Django
Library
associated with this registry. If omitted, the default Library instance from django_components is used. -
settings
(Union[RegistrySettings, Callable[[ComponentRegistry], RegistrySettings]]
, default:None
) \u2013Configure how the components registered with this registry will behave when rendered. See
RegistrySettings
. Can be either a static value or a callable that returns the settings. If omitted, the settings fromCOMPONENTS
are used.
Notes:
- The default registry is available as
django_components.registry
. - The default registry is used when registering components with
@register
decorator.
Example:
"},{"location":"reference/api/#django_components.ComponentRegistry--using-registry-to-share-components","title":"Using registry to share components","text":"# Use with default Library\nregistry = ComponentRegistry()\n\n# Or a custom one\nmy_lib = Library()\nregistry = ComponentRegistry(library=my_lib)\n\n# Usage\nregistry.register(\"button\", ButtonComponent)\nregistry.register(\"card\", CardComponent)\nregistry.all()\nregistry.clear()\nregistry.get()\n
You can use component registry for isolating or \"packaging\" components:
-
Create new instance of
ComponentRegistry
and Library:my_comps = Library()\nmy_comps_reg = ComponentRegistry(library=my_comps)\n
-
Register components to the registry:
my_comps_reg.register(\"my_button\", ButtonComponent)\nmy_comps_reg.register(\"my_card\", CardComponent)\n
-
In your target project, load the Library associated with the registry:
{% load my_comps %}\n
-
Use the registered components in your templates:
{% component \"button\" %}\n{% endcomponent %}\n
Methods:
-
all
\u2013 -
clear
\u2013 -
get
\u2013 -
register
\u2013 -
unregister
\u2013
Attributes:
-
library
(Library
) \u2013 -
settings
(InternalRegistrySettings
) \u2013
property
","text":"library: Library\n
See source code
The template tag
"},{"location":"reference/api/#django_components.ComponentRegistry.settings","title":"settingsLibrary
that is associated with the registry.property
","text":"settings: InternalRegistrySettings\n
See source code
Registry settings configured for this registry.
"},{"location":"reference/api/#django_components.ComponentRegistry.all","title":"all","text":"all() -> Dict[str, Type[Component]]\n
See source code
Retrieve all registered
Component
classes.Returns:
-
Dict[str, Type[Component]]
\u2013Dict[str, Type[Component]]: A dictionary of component names to component classes
Example:
"},{"location":"reference/api/#django_components.ComponentRegistry.clear","title":"clear","text":"# First register components\nregistry.register(\"button\", ButtonComponent)\nregistry.register(\"card\", CardComponent)\n# Then get all\nregistry.all()\n# > {\n# > \"button\": ButtonComponent,\n# > \"card\": CardComponent,\n# > }\n
clear() -> None\n
See source code
Clears the registry, unregistering all components.
Example:
"},{"location":"reference/api/#django_components.ComponentRegistry.get","title":"get","text":"# First register components\nregistry.register(\"button\", ButtonComponent)\nregistry.register(\"card\", CardComponent)\n# Then clear\nregistry.clear()\n# Then get all\nregistry.all()\n# > {}\n
get(name: str) -> Type[Component]\n
See source code
Retrieve a
Component
class registered under the given name.Parameters:
-
name
(str
) \u2013The name under which the component was registered. Required.
Returns:
-
Type[Component]
\u2013Type[Component]: The component class registered under the given name.
Raises:
NotRegistered
if the given name is not registered.
Example:
"},{"location":"reference/api/#django_components.ComponentRegistry.register","title":"register","text":"# First register component\nregistry.register(\"button\", ButtonComponent)\n# Then get\nregistry.get(\"button\")\n# > ButtonComponent\n
register(name: str, component: Type[Component]) -> None\n
See source code
Register a
Component
class with this registry under the given name.A component MUST be registered before it can be used in a template such as:
{% component \"my_comp\" %}\n{% endcomponent %}\n
Parameters:
-
name
(str
) \u2013The name under which the component will be registered. Required.
-
component
(Type[Component]
) \u2013The component class to register. Required.
Raises:
AlreadyRegistered
if a different component was already registered under the same name.
Example:
"},{"location":"reference/api/#django_components.ComponentRegistry.unregister","title":"unregister","text":"registry.register(\"button\", ButtonComponent)\n
unregister(name: str) -> None\n
See source code
Unregister the
Component
class that was registered under the given name.Once a component is unregistered, it is no longer available in the templates.
Parameters:
-
name
(str
) \u2013The name under which the component is registered. Required.
Raises:
NotRegistered
if the given name is not registered.
Example:
"},{"location":"reference/api/#django_components.ComponentVars","title":"ComponentVars","text":"# First register component\nregistry.register(\"button\", ButtonComponent)\n# Then unregister\nregistry.unregister(\"button\")\n
Bases:
tuple
See source code
Type for the variables available inside the component templates.
All variables here are scoped under
component_vars.
, so e.g. attributeis_filled
on this class is accessible inside the template as:{{ component_vars.is_filled }}\n
Attributes:
-
is_filled
(Dict[str, bool]
) \u2013
instance-attribute
","text":"is_filled: Dict[str, bool]\n
See source code
Dictonary describing which component slots are filled (
True
) or are not (False
).New in version 0.70
Use as
{{ component_vars.is_filled }}
Example:
{# Render wrapping HTML only if the slot is defined #}\n{% if component_vars.is_filled.my_slot %}\n <div class=\"slot-wrapper\">\n {% slot \"my_slot\" / %}\n </div>\n{% endif %}\n
This is equivalent to checking if a given key is among the slot fills:
"},{"location":"reference/api/#django_components.ComponentView","title":"ComponentView","text":"class MyTable(Component):\n def get_context_data(self, *args, **kwargs):\n return {\n \"my_slot_filled\": \"my_slot\" in self.input.slots\n }\n
ComponentView(component: Component, **kwargs: Any)\n
Bases:
django.views.generic.base.View
See source code
Subclass of
django.views.View
where theComponent
instance is available viaself.component
.Attributes:
-
component
\u2013
class-attribute
instance-attribute
","text":"
"},{"location":"reference/api/#django_components.ComponentsSettings","title":"ComponentsSettings","text":"component = component\n
Bases:
tuple
See source code
Settings available for django_components.
Example:
COMPONENTS = ComponentsSettings(\n autodiscover=False,\n dirs = [BASE_DIR / \"components\"],\n)\n
Attributes:
-
app_dirs
(Optional[Sequence[str]]
) \u2013 -
autodiscover
(Optional[bool]
) \u2013 -
cache
(Optional[str]
) \u2013 -
context_behavior
(Optional[ContextBehaviorType]
) \u2013 -
debug_highlight_components
(Optional[bool]
) \u2013 -
debug_highlight_slots
(Optional[bool]
) \u2013 -
dirs
(Optional[Sequence[Union[str, PathLike, Tuple[str, str], Tuple[str, PathLike]]]]
) \u2013 -
dynamic_component_name
(Optional[str]
) \u2013 -
forbidden_static_files
(Optional[List[Union[str, Pattern]]]
) \u2013 -
libraries
(Optional[List[str]]
) \u2013 -
multiline_tags
(Optional[bool]
) \u2013 -
reload_on_file_change
(Optional[bool]
) \u2013 -
reload_on_template_change
(Optional[bool]
) \u2013 -
static_files_allowed
(Optional[List[Union[str, Pattern]]]
) \u2013 -
static_files_forbidden
(Optional[List[Union[str, Pattern]]]
) \u2013 -
tag_formatter
(Optional[Union[TagFormatterABC, str]]
) \u2013 -
template_cache_size
(Optional[int]
) \u2013
class-attribute
instance-attribute
","text":"app_dirs: Optional[Sequence[str]] = None\n
See source code
Specify the app-level directories that contain your components.
Defaults to
[\"components\"]
. That is, for each Django app, we search<app>/components/
for components.The paths must be relative to app, e.g.:
COMPONENTS = ComponentsSettings(\n app_dirs=[\"my_comps\"],\n)\n
To search for
<app>/my_comps/
.These locations are searched during autodiscovery, or when you define HTML, JS, or CSS as separate files.
Set to empty list to disable app-level components:
"},{"location":"reference/api/#django_components.ComponentsSettings.autodiscover","title":"autodiscoverCOMPONENTS = ComponentsSettings(\n app_dirs=[],\n)\n
class-attribute
instance-attribute
","text":"autodiscover: Optional[bool] = None\n
See source code
Toggle whether to run autodiscovery at the Django server startup.
Defaults to
True
"},{"location":"reference/api/#django_components.ComponentsSettings.cache","title":"cacheCOMPONENTS = ComponentsSettings(\n autodiscover=False,\n)\n
class-attribute
instance-attribute
","text":"cache: Optional[str] = None\n
See source code
Name of the Django cache to be used for storing component's JS and CSS files.
If
None
, aLocMemCache
is used with default settings.Defaults to
None
.Read more about caching.
"},{"location":"reference/api/#django_components.ComponentsSettings.context_behavior","title":"context_behaviorCOMPONENTS = ComponentsSettings(\n cache=\"my_cache\",\n)\n
class-attribute
instance-attribute
","text":"context_behavior: Optional[ContextBehaviorType] = None\n
See source code
Configure whether, inside a component template, you can use variables from the outside (
\"django\"
) or not (\"isolated\"
). This also affects what variables are available inside the{% fill %}
tags.Also see Component context and scope.
Defaults to
\"django\"
.COMPONENTS = ComponentsSettings(\n context_behavior=\"isolated\",\n)\n
NOTE:
context_behavior
andslot_context_behavior
options were merged in v0.70.If you are migrating from BEFORE v0.67, set
context_behavior
to\"django\"
. From v0.67 to v0.78 (incl) the default value was\"isolated\"
.For v0.79 and later, the default is again
"},{"location":"reference/api/#django_components.ComponentsSettings.debug_highlight_components","title":"debug_highlight_components\"django\"
. See the rationale for change here.class-attribute
instance-attribute
","text":"debug_highlight_components: Optional[bool] = None\n
See source code
Enable / disable component highlighting. See Troubleshooting for more details.
Defaults to
False
.
"},{"location":"reference/api/#django_components.ComponentsSettings.debug_highlight_slots","title":"debug_highlight_slotsCOMPONENTS = ComponentsSettings(\n debug_highlight_components=True,\n)\n
class-attribute
instance-attribute
","text":"debug_highlight_slots: Optional[bool] = None\n
See source code
Enable / disable slot highlighting. See Troubleshooting for more details.
Defaults to
False
.
"},{"location":"reference/api/#django_components.ComponentsSettings.dirs","title":"dirsCOMPONENTS = ComponentsSettings(\n debug_highlight_slots=True,\n)\n
class-attribute
instance-attribute
","text":"dirs: Optional[Sequence[Union[str, PathLike, Tuple[str, str], Tuple[str, PathLike]]]] = None\n
See source code
Specify the directories that contain your components.
Defaults to
[Path(settings.BASE_DIR) / \"components\"]
. That is, the rootcomponents/
app.Directories must be full paths, same as with STATICFILES_DIRS.
These locations are searched during autodiscovery, or when you define HTML, JS, or CSS as separate files.
COMPONENTS = ComponentsSettings(\n dirs=[BASE_DIR / \"components\"],\n)\n
Set to empty list to disable global components directories:
"},{"location":"reference/api/#django_components.ComponentsSettings.dynamic_component_name","title":"dynamic_component_nameCOMPONENTS = ComponentsSettings(\n dirs=[],\n)\n
class-attribute
instance-attribute
","text":"dynamic_component_name: Optional[str] = None\n
See source code
By default, the dynamic component is registered under the name
\"dynamic\"
.In case of a conflict, you can use this setting to change the component name used for the dynamic components.
# settings.py\nCOMPONENTS = ComponentsSettings(\n dynamic_component_name=\"my_dynamic\",\n)\n
After which you will be able to use the dynamic component with the new name:
"},{"location":"reference/api/#django_components.ComponentsSettings.forbidden_static_files","title":"forbidden_static_files{% component \"my_dynamic\" is=table_comp data=table_data headers=table_headers %}\n {% fill \"pagination\" %}\n {% component \"pagination\" / %}\n {% endfill %}\n{% endcomponent %}\n
class-attribute
instance-attribute
","text":"forbidden_static_files: Optional[List[Union[str, Pattern]]] = None\n
See source code
Deprecated. Use
"},{"location":"reference/api/#django_components.ComponentsSettings.libraries","title":"librariesCOMPONENTS.static_files_forbidden
instead.class-attribute
instance-attribute
","text":"libraries: Optional[List[str]] = None\n
See source code
Configure extra python modules that should be loaded.
This may be useful if you are not using the autodiscovery feature, or you need to load components from non-standard locations. Thus you can have a structure of components that is independent from your apps.
Expects a list of python module paths. Defaults to empty list.
Example:
COMPONENTS = ComponentsSettings(\n libraries=[\n \"mysite.components.forms\",\n \"mysite.components.buttons\",\n \"mysite.components.cards\",\n ],\n)\n
This would be the equivalent of importing these modules from within Django's
AppConfig.ready()
:
"},{"location":"reference/api/#django_components.ComponentsSettings.libraries--manually-loading-libraries","title":"Manually loading libraries","text":"class MyAppConfig(AppConfig):\n def ready(self):\n import \"mysite.components.forms\"\n import \"mysite.components.buttons\"\n import \"mysite.components.cards\"\n
In the rare case that you need to manually trigger the import of libraries, you can use the
import_libraries()
function:
"},{"location":"reference/api/#django_components.ComponentsSettings.multiline_tags","title":"multiline_tagsfrom django_components import import_libraries\n\nimport_libraries()\n
class-attribute
instance-attribute
","text":"multiline_tags: Optional[bool] = None\n
See source code
Enable / disable multiline support for template tags. If
True
, template tags like{% component %}
or{{ my_var }}
can span multiple lines.Defaults to
True
.Disable this setting if you are making custom modifications to Django's regular expression for parsing templates at
django.template.base.tag_re
.
"},{"location":"reference/api/#django_components.ComponentsSettings.reload_on_file_change","title":"reload_on_file_changeCOMPONENTS = ComponentsSettings(\n multiline_tags=False,\n)\n
class-attribute
instance-attribute
","text":"reload_on_file_change: Optional[bool] = None\n
See source code
This is relevant if you are using the project structure where HTML, JS, CSS and Python are in separate files and nested in a directory.
In this case you may notice that when you are running a development server, the server sometimes does not reload when you change component files.
Django's native live reload logic handles only Python files and HTML template files. It does NOT reload when other file types change or when template files are nested more than one level deep.
The setting
reload_on_file_change
fixes this, reloading the dev server even when your component's HTML, JS, or CSS changes.If
True
, django_components configures Django to reload when files insideCOMPONENTS.dirs
orCOMPONENTS.app_dirs
change.See Reload dev server on component file changes.
Defaults to
False
.Warning
This setting should be enabled only for the dev environment!
"},{"location":"reference/api/#django_components.ComponentsSettings.reload_on_template_change","title":"reload_on_template_changeclass-attribute
instance-attribute
","text":"reload_on_template_change: Optional[bool] = None\n
See source code
Deprecated. Use
"},{"location":"reference/api/#django_components.ComponentsSettings.static_files_allowed","title":"static_files_allowedCOMPONENTS.reload_on_file_change
instead.class-attribute
instance-attribute
","text":"static_files_allowed: Optional[List[Union[str, Pattern]]] = None\n
See source code
A list of file extensions (including the leading dot) that define which files within
COMPONENTS.dirs
orCOMPONENTS.app_dirs
are treated as static files.If a file is matched against any of the patterns, it's considered a static file. Such files are collected when running
collectstatic
, and can be accessed under the static file endpoint.You can also pass in compiled regexes (
re.Pattern
) for more advanced patterns.By default, JS, CSS, and common image and font file formats are considered static files:
COMPONENTS = ComponentsSettings(\n static_files_allowed=[\n \".css\",\n \".js\", \".jsx\", \".ts\", \".tsx\",\n # Images\n \".apng\", \".png\", \".avif\", \".gif\", \".jpg\",\n \".jpeg\", \".jfif\", \".pjpeg\", \".pjp\", \".svg\",\n \".webp\", \".bmp\", \".ico\", \".cur\", \".tif\", \".tiff\",\n # Fonts\n \".eot\", \".ttf\", \".woff\", \".otf\", \".svg\",\n ],\n)\n
Warning
Exposing your Python files can be a security vulnerability. See Security notes.
"},{"location":"reference/api/#django_components.ComponentsSettings.static_files_forbidden","title":"static_files_forbiddenclass-attribute
instance-attribute
","text":"static_files_forbidden: Optional[List[Union[str, Pattern]]] = None\n
See source code
A list of file extensions (including the leading dot) that define which files within
COMPONENTS.dirs
orCOMPONENTS.app_dirs
will NEVER be treated as static files.If a file is matched against any of the patterns, it will never be considered a static file, even if the file matches a pattern in
static_files_allowed
.Use this setting together with
static_files_allowed
for a fine control over what file types will be exposed.You can also pass in compiled regexes (
re.Pattern
) for more advanced patterns.By default, any HTML and Python are considered NOT static files:
COMPONENTS = ComponentsSettings(\n static_files_forbidden=[\n \".html\", \".django\", \".dj\", \".tpl\",\n # Python files\n \".py\", \".pyc\",\n ],\n)\n
Warning
Exposing your Python files can be a security vulnerability. See Security notes.
"},{"location":"reference/api/#django_components.ComponentsSettings.tag_formatter","title":"tag_formatterclass-attribute
instance-attribute
","text":"tag_formatter: Optional[Union[TagFormatterABC, str]] = None\n
See source code
Configure what syntax is used inside Django templates to render components. See the available tag formatters.
Defaults to
\"django_components.component_formatter\"
.Learn more about Customizing component tags with TagFormatter.
Can be set either as direct reference:
from django_components import component_formatter\n\nCOMPONENTS = ComponentsSettings(\n \"tag_formatter\": component_formatter\n)\n
Or as an import string;
COMPONENTS = ComponentsSettings(\n \"tag_formatter\": \"django_components.component_formatter\"\n)\n
Examples:
-
\"django_components.component_formatter\"
Set
COMPONENTS = ComponentsSettings(\n \"tag_formatter\": \"django_components.component_formatter\"\n)\n
To write components like this:
{% component \"button\" href=\"...\" %}\n Click me!\n{% endcomponent %}\n
-
django_components.component_shorthand_formatter
Set
COMPONENTS = ComponentsSettings(\n \"tag_formatter\": \"django_components.component_shorthand_formatter\"\n)\n
To write components like this:
{% button href=\"...\" %}\n Click me!\n{% endbutton %}\n
class-attribute
instance-attribute
","text":"template_cache_size: Optional[int] = None\n
See source code
Configure the maximum amount of Django templates to be cached.
Defaults to
128
.Each time a Django template is rendered, it is cached to a global in-memory cache (using Python's
lru_cache
decorator). This speeds up the next render of the component. As the same component is often used many times on the same page, these savings add up.By default the cache holds 128 component templates in memory, which should be enough for most sites. But if you have a lot of components, or if you are overriding
Component.get_template()
to render many dynamic templates, you can increase this number.COMPONENTS = ComponentsSettings(\n template_cache_size=256,\n)\n
To remove the cache limit altogether and cache everything, set
template_cache_size
toNone
.COMPONENTS = ComponentsSettings(\n template_cache_size=None,\n)\n
If you want to add templates to the cache yourself, you can use
cached_template()
:
"},{"location":"reference/api/#django_components.ContextBehavior","title":"ContextBehavior","text":"from django_components import cached_template\n\ncached_template(\"Variable: {{ variable }}\")\n\n# You can optionally specify Template class, and other Template inputs:\nclass MyTemplate(Template):\n pass\n\ncached_template(\n \"Variable: {{ variable }}\",\n template_cls=MyTemplate,\n name=...\n origin=...\n engine=...\n)\n
Bases:
str
,enum.Enum
See source code
Configure how (and whether) the context is passed to the component fills and what variables are available inside the
{% fill %}
tags.Also see Component context and scope.
Options:
django
: With this setting, component fills behave as usual Django tags.isolated
: This setting makes the component fills behave similar to Vue or React.
Attributes:
-
DJANGO
\u2013 -
ISOLATED
\u2013
class-attribute
instance-attribute
","text":"DJANGO = 'django'\n
See source code
With this setting, component fills behave as usual Django tags. That is, they enrich the context, and pass it along.
- Component fills use the context of the component they are within.
- Variables from
Component.get_context_data()
are available to the component fill.
Example:
Given this template
{% with cheese=\"feta\" %}\n {% component 'my_comp' %}\n {{ my_var }} # my_var\n {{ cheese }} # cheese\n {% endcomponent %}\n{% endwith %}\n
and this context returned from the
Component.get_context_data()
method{ \"my_var\": 123 }\n
Then if component \"my_comp\" defines context
{ \"my_var\": 456 }\n
Then this will render:
456 # my_var\nfeta # cheese\n
Because \"my_comp\" overrides the variable \"my_var\", so
{{ my_var }}
equals456
.And variable \"cheese\" will equal
"},{"location":"reference/api/#django_components.ContextBehavior.ISOLATED","title":"ISOLATEDfeta
, because the fill CAN access the current context.class-attribute
instance-attribute
","text":"ISOLATED = 'isolated'\n
See source code
This setting makes the component fills behave similar to Vue or React, where the fills use EXCLUSIVELY the context variables defined in
Component.get_context_data()
.Example:
Given this template
{% with cheese=\"feta\" %}\n {% component 'my_comp' %}\n {{ my_var }} # my_var\n {{ cheese }} # cheese\n {% endcomponent %}\n{% endwith %}\n
and this context returned from the
get_context_data()
method{ \"my_var\": 123 }\n
Then if component \"my_comp\" defines context
{ \"my_var\": 456 }\n
Then this will render:
123 # my_var\n # cheese\n
Because both variables \"my_var\" and \"cheese\" are taken from the root context. Since \"cheese\" is not defined in root context, it's empty.
"},{"location":"reference/api/#django_components.EmptyDict","title":"EmptyDict","text":"Bases:
dict
See source code
TypedDict with no members.
You can use this to define a Component that accepts NO kwargs, or NO slots, or returns NO data from
Component.get_context_data()
/Component.get_js_data()
/Component.get_css_data()
:Accepts NO kwargs:
from django_components import Component, EmptyDict\n\nclass Table(Component(Any, EmptyDict, Any, Any, Any, Any))\n ...\n
Accepts NO slots:
from django_components import Component, EmptyDict\n\nclass Table(Component(Any, Any, EmptyDict, Any, Any, Any))\n ...\n
Returns NO data from
get_context_data()
:from django_components import Component, EmptyDict\n\nclass Table(Component(Any, Any, Any, EmptyDict, Any, Any))\n ...\n
Going back to the example with NO kwargs, when you then call
Component.render()
orComponent.render_to_response()
, thekwargs
parameter will raise type error ifkwargs
is anything else than an empty dict.Table.render(\n kwargs: {},\n)\n
Omitting
kwargs
is also fine:Table.render()\n
Other values are not allowed. This will raise an error with MyPy:
"},{"location":"reference/api/#django_components.EmptyTuple","title":"EmptyTupleTable.render(\n kwargs: {\n \"one\": 2,\n \"three\": 4,\n },\n)\n
module-attribute
","text":"EmptyTuple = Tuple[]\n
See source code
Tuple with no members.
You can use this to define a Component that accepts NO positional arguments:
from django_components import Component, EmptyTuple\n\nclass Table(Component(EmptyTuple, Any, Any, Any, Any, Any))\n ...\n
After that, when you call
Component.render()
orComponent.render_to_response()
, theargs
parameter will raise type error ifargs
is anything else than an empty tuple.Table.render(\n args: (),\n)\n
Omitting
args
is also fine:Table.render()\n
Other values are not allowed. This will raise an error with MyPy:
"},{"location":"reference/api/#django_components.RegistrySettings","title":"RegistrySettings","text":"Table.render(\n args: (\"one\", 2, \"three\"),\n)\n
Bases:
tuple
See source code
Configuration for a
ComponentRegistry
.These settings define how the components registered with this registry will behave when rendered.
from django_components import ComponentRegistry, RegistrySettings\n\nregistry_settings = RegistrySettings(\n context_behavior=\"django\",\n tag_formatter=\"django_components.component_shorthand_formatter\",\n)\n\nregistry = ComponentRegistry(settings=registry_settings)\n
Attributes:
-
CONTEXT_BEHAVIOR
(Optional[ContextBehaviorType]
) \u2013 -
TAG_FORMATTER
(Optional[Union[TagFormatterABC, str]]
) \u2013 -
context_behavior
(Optional[ContextBehaviorType]
) \u2013 -
tag_formatter
(Optional[Union[TagFormatterABC, str]]
) \u2013
class-attribute
instance-attribute
","text":"CONTEXT_BEHAVIOR: Optional[ContextBehaviorType] = None\n
See source code
Deprecated. Use
context_behavior
instead. Will be removed in v1.Same as the global
COMPONENTS.context_behavior
setting, but for this registry.If omitted, defaults to the global
"},{"location":"reference/api/#django_components.RegistrySettings.TAG_FORMATTER","title":"TAG_FORMATTERCOMPONENTS.context_behavior
setting.class-attribute
instance-attribute
","text":"TAG_FORMATTER: Optional[Union[TagFormatterABC, str]] = None\n
See source code
Deprecated. Use
tag_formatter
instead. Will be removed in v1.Same as the global
COMPONENTS.tag_formatter
setting, but for this registry.If omitted, defaults to the global
"},{"location":"reference/api/#django_components.RegistrySettings.context_behavior","title":"context_behaviorCOMPONENTS.tag_formatter
setting.class-attribute
instance-attribute
","text":"context_behavior: Optional[ContextBehaviorType] = None\n
See source code
Same as the global
COMPONENTS.context_behavior
setting, but for this registry.If omitted, defaults to the global
"},{"location":"reference/api/#django_components.RegistrySettings.tag_formatter","title":"tag_formatterCOMPONENTS.context_behavior
setting.class-attribute
instance-attribute
","text":"tag_formatter: Optional[Union[TagFormatterABC, str]] = None\n
See source code
Same as the global
COMPONENTS.tag_formatter
setting, but for this registry.If omitted, defaults to the global
"},{"location":"reference/api/#django_components.Slot","title":"SlotCOMPONENTS.tag_formatter
setting.dataclass
","text":"Slot(\n content_func: SlotFunc[TSlotData],\n escaped: bool = False,\n component_name: Optional[str] = None,\n slot_name: Optional[str] = None,\n nodelist: Optional[NodeList] = None,\n)\n
Bases:
typing.Generic
See source code
This class holds the slot content function along with related metadata.
Attributes:
-
component_name
(Optional[str]
) \u2013 -
content_func
(SlotFunc[TSlotData]
) \u2013 -
do_not_call_in_templates
(bool
) \u2013 -
escaped
(bool
) \u2013 -
nodelist
(Optional[NodeList]
) \u2013 -
slot_name
(Optional[str]
) \u2013
class-attribute
instance-attribute
","text":"component_name: Optional[str] = None\n
See source code
Name of the component that originally defined or accepted this slot fill.
"},{"location":"reference/api/#django_components.Slot.content_func","title":"content_funcinstance-attribute
","text":"
"},{"location":"reference/api/#django_components.Slot.do_not_call_in_templates","title":"do_not_call_in_templatescontent_func: SlotFunc[TSlotData]\n
property
","text":"
"},{"location":"reference/api/#django_components.Slot.escaped","title":"escapeddo_not_call_in_templates: bool\n
class-attribute
instance-attribute
","text":"escaped: bool = False\n
See source code
Whether the slot content has been escaped.
"},{"location":"reference/api/#django_components.Slot.nodelist","title":"nodelistclass-attribute
instance-attribute
","text":"nodelist: Optional[NodeList] = None\n
See source code
Nodelist of the slot content.
"},{"location":"reference/api/#django_components.Slot.slot_name","title":"slot_nameclass-attribute
instance-attribute
","text":"slot_name: Optional[str] = None\n
See source code
Name of the slot that originally defined or accepted this slot fill.
"},{"location":"reference/api/#django_components.SlotContent","title":"SlotContentmodule-attribute
","text":"
"},{"location":"reference/api/#django_components.SlotFunc","title":"SlotFunc","text":""},{"location":"reference/api/#django_components.SlotRef","title":"SlotRef","text":"SlotContent = Union[SlotResult, SlotFunc[TSlotData], 'Slot[TSlotData]']\n
SlotRef(slot: SlotNode, context: Context)\n
Bases:
object
See source code
SlotRef allows to treat a slot as a variable. The slot is rendered only once the instance is coerced to string.
This is used to access slots as variables inside the templates. When a SlotRef is rendered in the template with
"},{"location":"reference/api/#django_components.SlotResult","title":"SlotResult{{ my_lazy_slot }}
, it will output the contents of the slot.module-attribute
","text":"
"},{"location":"reference/api/#django_components.TagFormatterABC","title":"TagFormatterABC","text":"SlotResult = Union[str, SafeString]\n
Bases:
abc.ABC
See source code
Abstract base class for defining custom tag formatters.
Tag formatters define how the component tags are used in the template.
Read more about Tag formatter.
For example, with the default tag formatter (
ComponentFormatter
), components are written as:{% component \"comp_name\" %}\n{% endcomponent %}\n
While with the shorthand tag formatter (
ShorthandComponentFormatter
), components are written as:{% comp_name %}\n{% endcomp_name %}\n
Example:
Implementation for
ShorthandComponentFormatter
:from djagno_components import TagFormatterABC, TagResult\n\nclass ShorthandComponentFormatter(TagFormatterABC):\n def start_tag(self, name: str) -> str:\n return name\n\n def end_tag(self, name: str) -> str:\n return f\"end{name}\"\n\n def parse(self, tokens: List[str]) -> TagResult:\n tokens = [*tokens]\n name = tokens.pop(0)\n return TagResult(name, tokens)\n
Methods:
-
end_tag
\u2013 -
parse
\u2013 -
start_tag
\u2013
abstractmethod
","text":"end_tag(name: str) -> str\n
See source code
Formats the end tag of a block component.
Parameters:
-
name
(str
) \u2013Component's registered name. Required.
Returns:
-
str
(str
) \u2013The formatted end tag.
abstractmethod
","text":"parse(tokens: List[str]) -> TagResult\n
See source code
Given the tokens (words) passed to a component start tag, this function extracts the component name from the tokens list, and returns
TagResult
, which is a tuple of(component_name, remaining_tokens)
.Parameters:
-
tokens
([List(str]
) \u2013List of tokens passed to the component tag.
Returns:
-
TagResult
(TagResult
) \u2013Parsed component name and remaining tokens.
Example:
Assuming we used a component in a template like this:
{% component \"my_comp\" key=val key2=val2 %}\n{% endcomponent %}\n
This function receives a list of tokens:
['component', '\"my_comp\"', 'key=val', 'key2=val2']\n
component
is the tag name, which we drop.\"my_comp\"
is the component name, but we must remove the extra quotes.- The remaining tokens we pass unmodified, as that's the input to the component.
So in the end, we return:
"},{"location":"reference/api/#django_components.TagFormatterABC.start_tag","title":"start_tagTagResult('my_comp', ['key=val', 'key2=val2'])\n
abstractmethod
","text":"start_tag(name: str) -> str\n
See source code
Formats the start tag of a component.
Parameters:
-
name
(str
) \u2013Component's registered name. Required.
Returns:
-
str
(str
) \u2013The formatted start tag.
Bases:
tuple
See source code
The return value from
TagFormatter.parse()
.Read more about Tag formatter.
Attributes:
-
component_name
(str
) \u2013 -
tokens
(List[str]
) \u2013
instance-attribute
","text":"component_name: str\n
See source code
Component name extracted from the template tag
For example, if we had tag
{% component \"my_comp\" key=val key2=val2 %}\n
Then
"},{"location":"reference/api/#django_components.TagResult.tokens","title":"tokenscomponent_name
would bemy_comp
.instance-attribute
","text":"tokens: List[str]\n
See source code
Remaining tokens (words) that were passed to the tag, with component name removed
For example, if we had tag
{% component \"my_comp\" key=val key2=val2 %}\n
Then
"},{"location":"reference/api/#django_components.autodiscover","title":"autodiscover","text":"tokens
would be['key=val', 'key2=val2']
.autodiscover(map_module: Optional[Callable[[str], str]] = None) -> List[str]\n
See source code
Search for all python files in
COMPONENTS.dirs
andCOMPONENTS.app_dirs
and import them.See Autodiscovery.
NOTE: Subdirectories and files starting with an underscore
_
(except for__init__.py
are ignored.Parameters:
-
map_module
(Callable[[str], str]
, default:None
) \u2013Map the module paths with
map_module
function. This serves as an escape hatch for when you need to use this function in tests.
Returns:
-
List[str]
\u2013List[str]: A list of module paths of imported files.
To get the same list of modules that
autodiscover()
would return, but without importing them, useget_component_files()
:
"},{"location":"reference/api/#django_components.cached_template","title":"cached_template","text":"from django_components import get_component_files\n\nmodules = get_component_files(\".py\")\n
cached_template(\n template_string: str,\n template_cls: Optional[Type[Template]] = None,\n origin: Optional[Origin] = None,\n name: Optional[str] = None,\n engine: Optional[Any] = None,\n) -> Template\n
See source code
Create a Template instance that will be cached as per the
COMPONENTS.template_cache_size
setting.Parameters:
-
template_string
(str
) \u2013Template as a string, same as the first argument to Django's
Template
. Required. -
template_cls
(Type[Template]
, default:None
) \u2013Specify the Template class that should be instantiated. Defaults to Django's
Template
class. -
origin
(Type[Origin]
, default:None
) \u2013Sets
Template.Origin
. -
name
(Type[str]
, default:None
) \u2013Sets
Template.name
-
engine
(Type[Any]
, default:None
) \u2013Sets
Template.engine
"},{"location":"reference/api/#django_components.get_component_dirs","title":"get_component_dirs","text":"from django_components import cached_template\n\ntemplate = cached_template(\"Variable: {{ variable }}\")\n\n# You can optionally specify Template class, and other Template inputs:\nclass MyTemplate(Template):\n pass\n\ntemplate = cached_template(\n \"Variable: {{ variable }}\",\n template_cls=MyTemplate,\n name=...\n origin=...\n engine=...\n)\n
get_component_dirs(include_apps: bool = True) -> List[Path]\n
See source code
Get directories that may contain component files.
This is the heart of all features that deal with filesystem and file lookup. Autodiscovery, Django template resolution, static file resolution - They all use this.
Parameters:
-
include_apps
(bool
, default:True
) \u2013Include directories from installed Django apps. Defaults to
True
.
Returns:
-
List[Path]
\u2013List[Path]: A list of directories that may contain component files.
get_component_dirs()
searches for dirs set inCOMPONENTS.dirs
settings. If none set, defaults to searching for a\"components\"
app.In addition to that, also all installed Django apps are checked whether they contain directories as set in
COMPONENTS.app_dirs
(e.g.[app]/components
).Notes:
-
Paths that do not point to directories are ignored.
-
BASE_DIR
setting is required. -
The paths in
COMPONENTS.dirs
must be absolute paths.
get_component_files(suffix: Optional[str] = None) -> List[ComponentFileEntry]\n
See source code
Search for files within the component directories (as defined in
get_component_dirs()
).Requires
BASE_DIR
setting to be set.Subdirectories and files starting with an underscore
_
(except__init__.py
) are ignored.Parameters:
-
suffix
(Optional[str]
, default:None
) \u2013The suffix to search for. E.g.
.py
,.js
,.css
. Defaults toNone
, which will search for all files.
Returns:
-
List[ComponentFileEntry]
\u2013List[ComponentFileEntry] A list of entries that contain both the filesystem path and the python import path (dot path).
Example:
"},{"location":"reference/api/#django_components.import_libraries","title":"import_libraries","text":"from django_components import get_component_files\n\nmodules = get_component_files(\".py\")\n
import_libraries(map_module: Optional[Callable[[str], str]] = None) -> List[str]\n
See source code
Import modules set in
COMPONENTS.libraries
setting.See Autodiscovery.
Parameters:
-
map_module
(Callable[[str], str]
, default:None
) \u2013Map the module paths with
map_module
function. This serves as an escape hatch for when you need to use this function in tests.
Returns:
-
List[str]
\u2013List[str]: A list of module paths of imported files.
Examples:
Normal usage - load libraries after Django has loaded
from django_components import import_libraries\n\nclass MyAppConfig(AppConfig):\n def ready(self):\n import_libraries()\n
Potential usage in tests
"},{"location":"reference/api/#django_components.register","title":"register","text":"from django_components import import_libraries\n\nimport_libraries(lambda path: path.replace(\"tests.\", \"myapp.\"))\n
register(name: str, registry: Optional[ComponentRegistry] = None) -> Callable[\n [Type[Component[ArgsType, KwargsType, SlotsType, DataType, JsDataType, CssDataType]]],\n Type[Component[ArgsType, KwargsType, SlotsType, DataType, JsDataType, CssDataType]],\n]\n
See source code
Class decorator for registering a component to a component registry.
See Registering components.
Parameters:
-
name
(str
) \u2013Registered name. This is the name by which the component will be accessed from within a template when using the
{% component %}
tag. Required. -
registry
(ComponentRegistry
, default:None
) \u2013Specify the registry to which to register this component. If omitted, component is registered to the default registry.
Raises:
-
AlreadyRegistered
\u2013If there is already a component registered under the same name.
Examples:
from django_components import Component, register\n\n@register(\"my_component\")\nclass MyComponent(Component):\n ...\n
Specifing
ComponentRegistry
the component should be registered to by setting theregistry
kwarg:
"},{"location":"reference/api/#django_components.registry","title":"registryfrom django.template import Library\nfrom django_components import Component, ComponentRegistry, register\n\nmy_lib = Library()\nmy_reg = ComponentRegistry(library=my_lib)\n\n@register(\"my_component\", registry=my_reg)\nclass MyComponent(Component):\n ...\n
module-attribute
","text":"registry: ComponentRegistry = ComponentRegistry()\n
See source code
The default and global component registry. Use this instance to directly register or remove components:
See Registering components.
"},{"location":"reference/api/#django_components.render_dependencies","title":"render_dependencies","text":"# Register components\nregistry.register(\"button\", ButtonComponent)\nregistry.register(\"card\", CardComponent)\n\n# Get single\nregistry.get(\"button\")\n\n# Get all\nregistry.all()\n\n# Unregister single\nregistry.unregister(\"button\")\n\n# Unregister all\nregistry.clear()\n
render_dependencies(content: TContent, type: RenderType = 'document') -> TContent\n
See source code
Given a string that contains parts that were rendered by components, this function inserts all used JS and CSS.
By default, the string is parsed as an HTML and: - CSS is inserted at the end of
<head>
(if present) - JS is inserted at the end of<body>
(if present)If you used
{% component_js_dependencies %}
or{% component_css_dependencies %}
, then the JS and CSS will be inserted only at these locations.Example:
"},{"location":"reference/api/#django_components.template_tag","title":"template_tag","text":"def my_view(request):\n template = Template('''\n {% load components %}\n <!doctype html>\n <html>\n <head></head>\n <body>\n <h1>{{ table_name }}</h1>\n {% component \"table\" name=table_name / %}\n </body>\n </html>\n ''')\n\n html = template.render(\n Context({\n \"table_name\": request.GET[\"name\"],\n })\n )\n\n # This inserts components' JS and CSS\n processed_html = render_dependencies(html)\n\n return HttpResponse(processed_html)\n
template_tag(\n library: Library, tag: str, end_tag: Optional[str] = None, allowed_flags: Optional[List[str]] = None\n) -> Callable[[Callable], Callable]\n
See source code
A simplified version of creating a template tag based on
BaseNode
.Instead of defining the whole class, you can just define the
render()
method.from django.template import Context, Library\nfrom django_components import BaseNode, template_tag\n\nlibrary = Library()\n\n@template_tag(\n library,\n tag=\"mytag\",\n end_tag=\"endmytag\",\n allowed_flags=[\"required\"],\n)\ndef mytag(node: BaseNode, context: Context, name: str, **kwargs: Any) -> str:\n return f\"Hello, {name}!\"\n
This will allow the template tag
{% mytag %}
to be used like this:{% mytag name=\"John\" %}\n{% mytag name=\"John\" required %} ... {% endmytag %}\n
The given function will be wrapped in a class that inherits from
BaseNode
.And this class will be registered with the given library.
The function MUST accept at least two positional arguments:
node
andcontext
node
is theBaseNode
instance.context
is theContext
of the template.
Any extra parameters defined on this function will be part of the tag's input parameters.
For more info, see
"},{"location":"reference/commands/","title":"Commands","text":""},{"location":"reference/commands/#commands","title":"Commands","text":"BaseNode.render()
.These are all the Django management commands that will be added by installing
"},{"location":"reference/commands/#startcomponent","title":"django_components
:startcomponent
","text":"usage: manage.py startcomponent [-h] [--path PATH] [--js JS] [--css CSS]\n [--template TEMPLATE] [--force] [--verbose]\n [--dry-run] [--version] [-v {0,1,2,3}]\n [--settings SETTINGS]\n [--pythonpath PYTHONPATH] [--traceback]\n [--no-color] [--force-color] [--skip-checks]\n name\n
See source code
Create a new django component.
Positional Arguments:
name
- The name of the component to create. This is a required argument.
Options:
-h
,--help
- show this help message and exit
--path PATH
- The path to the component's directory. This is an optional argument. If not provided, the command will use the
COMPONENTS.dirs
setting from your Django settings.
- The path to the component's directory. This is an optional argument. If not provided, the command will use the
--js JS
- The name of the JavaScript file. This is an optional argument. The default value is
script.js
.
- The name of the JavaScript file. This is an optional argument. The default value is
--css CSS
- The name of the CSS file. This is an optional argument. The default value is
style.css
.
- The name of the CSS file. This is an optional argument. The default value is
--template TEMPLATE
- The name of the template file. This is an optional argument. The default value is
template.html
.
- The name of the template file. This is an optional argument. The default value is
--force
- This option allows you to overwrite existing files if they exist. This is an optional argument.
--verbose
- This option allows the command to print additional information during component creation. This is an optional argument.
--dry-run
- This option allows you to simulate component creation without actually creating any files. This is an optional argument. The default value is
False
.
- This option allows you to simulate component creation without actually creating any files. This is an optional argument. The default value is
--version
- Show program's version number and exit.
-v {0,1,2,3}
,--verbosity {0,1,2,3}
- Verbosity level; 0=minimal output, 1=normal output, 2=verbose output, 3=very verbose output
--settings SETTINGS
- The Python path to a settings module, e.g. \"myproject.settings.main\". If this isn't provided, the DJANGO_SETTINGS_MODULE environment variable will be used.
--pythonpath PYTHONPATH
- A directory to add to the Python path, e.g. \"/home/djangoprojects/myproject\".
--traceback
- Raise on CommandError exceptions.
--no-color
- Don't colorize the command output.
--force-color
- Force colorization of the command output.
--skip-checks
- Skip system checks.
To use the command, run the following command in your terminal:
python manage.py startcomponent <name> --path <path> --js <js_filename> --css <css_filename> --template <template_filename> --force --verbose --dry-run\n
Replace
"},{"location":"reference/commands/#management-command-examples","title":"Management Command Examples","text":"<name>
,<path>
,<js_filename>
,<css_filename>
, and<template_filename>
with your desired values.Here are some examples of how you can use the command:
"},{"location":"reference/commands/#creating-a-component-with-default-settings","title":"Creating a Component with Default Settings","text":"To create a component with the default settings, you only need to provide the name of the component:
python manage.py startcomponent my_component\n
This will create a new component named
"},{"location":"reference/commands/#creating-a-component-with-custom-settings","title":"Creating a Component with Custom Settings","text":"my_component
in thecomponents
directory of your Django project. The JavaScript, CSS, and template files will be namedscript.js
,style.css
, andtemplate.html
, respectively.You can also create a component with custom settings by providing additional arguments:
python manage.py startcomponent new_component --path my_components --js my_script.js --css my_style.css --template my_template.html\n
This will create a new component named
"},{"location":"reference/commands/#overwriting-an-existing-component","title":"Overwriting an Existing Component","text":"new_component
in themy_components
directory. The JavaScript, CSS, and template files will be namedmy_script.js
,my_style.css
, andmy_template.html
, respectively.If you want to overwrite an existing component, you can use the
--force
option:python manage.py startcomponent my_component --force\n
This will overwrite the existing
"},{"location":"reference/commands/#simulating-component-creation","title":"Simulating Component Creation","text":"my_component
if it exists.If you want to simulate the creation of a component without actually creating any files, you can use the
--dry-run
option:python manage.py startcomponent my_component --dry-run\n
This will simulate the creation of
"},{"location":"reference/commands/#upgradecomponent","title":"my_component
without creating any files.upgradecomponent
","text":"usage: manage.py upgradecomponent [-h] [--path PATH] [--version]\n [-v {0,1,2,3}] [--settings SETTINGS]\n [--pythonpath PYTHONPATH] [--traceback]\n [--no-color] [--force-color] [--skip-checks]\n
See source code
Updates component and component_block tags to the new syntax
Options:
-h
,--help
- show this help message and exit
--path PATH
- Path to search for components
--version
- Show program's version number and exit.
-v {0,1,2,3}
,--verbosity {0,1,2,3}
- Verbosity level; 0=minimal output, 1=normal output, 2=verbose output, 3=very verbose output
--settings SETTINGS
- The Python path to a settings module, e.g. \"myproject.settings.main\". If this isn't provided, the DJANGO_SETTINGS_MODULE environment variable will be used.
--pythonpath PYTHONPATH
- A directory to add to the Python path, e.g. \"/home/djangoprojects/myproject\".
--traceback
- Raise on CommandError exceptions.
--no-color
- Don't colorize the command output.
--force-color
- Force colorization of the command output.
--skip-checks
- Skip system checks.
These are the components provided by django_components.
"},{"location":"reference/components/#django_components.components.dynamic.DynamicComponent","title":"DynamicComponent
","text":"Bases:
django_components.component.Component
See source code
This component is given a registered name or a reference to another component, and behaves as if the other component was in its place.
The args, kwargs, and slot fills are all passed down to the underlying component.
Parameters:
-
is
(str | Type[Component]
) \u2013Component that should be rendered. Either a registered name of a component, or a Component class directly. Required.
-
registry
(ComponentRegistry
, default:None
) \u2013Specify the registry to search for the registered name. If omitted, all registries are searched until the first match.
-
*args
\u2013Additional data passed to the component.
-
**kwargs
\u2013Additional data passed to the component.
Slots:
- Any slots, depending on the actual component.
Examples:
Django
{% component \"dynamic\" is=table_comp data=table_data headers=table_headers %}\n {% fill \"pagination\" %}\n {% component \"pagination\" / %}\n {% endfill %}\n{% endcomponent %}\n
Or in case you use the
django_components.component_shorthand_formatter
tag formatter:{% dynamic is=table_comp data=table_data headers=table_headers %}\n {% fill \"pagination\" %}\n {% component \"pagination\" / %}\n {% endfill %}\n{% enddynamic %}\n
Python
"},{"location":"reference/components/#django_components.components.dynamic.DynamicComponent--use-cases","title":"Use cases","text":"from django_components import DynamicComponent\n\nDynamicComponent.render(\n kwargs={\n \"is\": table_comp,\n \"data\": table_data,\n \"headers\": table_headers,\n },\n slots={\n \"pagination\": PaginationComponent.render(\n render_dependencies=False,\n ),\n },\n)\n
Dynamic components are suitable if you are writing something like a form component. You may design it such that users give you a list of input types, and you render components depending on the input types.
While you could handle this with a series of if / else statements, that's not an extensible approach. Instead, you can use the dynamic component in place of normal components.
"},{"location":"reference/components/#django_components.components.dynamic.DynamicComponent--component-name","title":"Component name","text":"By default, the dynamic component is registered under the name
\"dynamic\"
. In case of a conflict, you can set theCOMPONENTS.dynamic_component_name
setting to change the name used for the dynamic components.# settings.py\nCOMPONENTS = ComponentsSettings(\n dynamic_component_name=\"my_dynamic\",\n)\n
After which you will be able to use the dynamic component with the new name:
"},{"location":"reference/exceptions/","title":"Exceptions","text":""},{"location":"reference/exceptions/#exceptions","title":"Exceptions","text":""},{"location":"reference/exceptions/#django_components.AlreadyRegistered","title":"AlreadyRegistered","text":"{% component \"my_dynamic\" is=table_comp data=table_data headers=table_headers %}\n {% fill \"pagination\" %}\n {% component \"pagination\" / %}\n {% endfill %}\n{% endcomponent %}\n
Bases:
Exception
See source code
Raised when you try to register a Component, but it's already registered with given ComponentRegistry.
"},{"location":"reference/exceptions/#django_components.NotRegistered","title":"NotRegistered","text":"Bases:
Exception
See source code
Raised when you try to access a Component, but it's NOT registered with given ComponentRegistry.
"},{"location":"reference/exceptions/#django_components.TagProtectedError","title":"TagProtectedError","text":"Bases:
Exception
See source code
The way the
TagFormatter
works is that, based on which start and end tags are used for rendering components, theComponentRegistry
behind the scenes un-/registers the template tags with the associated instance of Django'sLibrary
.In other words, if I have registered a component
\"table\"
, and I use the shorthand syntax:{% table ... %}\n{% endtable %}\n
Then
ComponentRegistry
registers the tagtable
onto the Django's Library instance.However, that means that if we registered a component
\"slot\"
, then we would overwrite the{% slot %}
tag from django_components.Thus, this exception is raised when a component is attempted to be registered under a forbidden name, such that it would overwrite one of django_component's own template tags.
"},{"location":"reference/middlewares/","title":"Middlewares","text":""},{"location":"reference/middlewares/#middlewares","title":"Middlewares","text":""},{"location":"reference/middlewares/#django_components.dependencies.ComponentDependencyMiddleware","title":"ComponentDependencyMiddleware
","text":"Bases:
object
See source code
Middleware that inserts CSS/JS dependencies for all rendered components at points marked with template tags.
"},{"location":"reference/settings/","title":"Settings","text":""},{"location":"reference/settings/#settings","title":"Settings","text":"You can configure django_components with a global
COMPONENTS
variable in your Django settings file, e.g.settings.py
. By default you don't need it set, there are resonable defaults.To configure the settings you can instantiate
ComponentsSettings
for validation and type hints. Or, for backwards compatibility, you can also use plain dictionary:
"},{"location":"reference/settings/#settings-defaults","title":"Settings defaults","text":"# settings.py\nfrom django_components import ComponentsSettings\n\nCOMPONENTS = ComponentsSettings(\n autodiscover=True,\n ...\n)\n\n# or\n\nCOMPONENTS = {\n \"autodiscover\": True,\n ...\n}\n
Here's overview of all available settings and their defaults:
"},{"location":"reference/settings/#django_components.app_settings.ComponentsSettings.app_dirs","title":"app_dirs","text":"defaults = ComponentsSettings(\n autodiscover=True,\n cache=None,\n context_behavior=ContextBehavior.DJANGO.value, # \"django\" | \"isolated\"\n # Root-level \"components\" dirs, e.g. `/path/to/proj/components/`\n dirs=[Path(settings.BASE_DIR) / \"components\"],\n # App-level \"components\" dirs, e.g. `[app]/components/`\n app_dirs=[\"components\"],\n debug_highlight_components=False,\n debug_highlight_slots=False,\n dynamic_component_name=\"dynamic\",\n libraries=[], # E.g. [\"mysite.components.forms\", ...]\n multiline_tags=True,\n reload_on_file_change=False,\n static_files_allowed=[\n \".css\",\n \".js\", \".jsx\", \".ts\", \".tsx\",\n # Images\n \".apng\", \".png\", \".avif\", \".gif\", \".jpg\",\n \".jpeg\", \".jfif\", \".pjpeg\", \".pjp\", \".svg\",\n \".webp\", \".bmp\", \".ico\", \".cur\", \".tif\", \".tiff\",\n # Fonts\n \".eot\", \".ttf\", \".woff\", \".otf\", \".svg\",\n ],\n static_files_forbidden=[\n # See https://marketplace.visualstudio.com/items?itemName=junstyle.vscode-django-support\n \".html\", \".django\", \".dj\", \".tpl\",\n # Python files\n \".py\", \".pyc\",\n ],\n tag_formatter=\"django_components.component_formatter\",\n template_cache_size=128,\n)\n
app_dirs: Optional[Sequence[str]] = None\n
See source code
Specify the app-level directories that contain your components.
Defaults to
[\"components\"]
. That is, for each Django app, we search<app>/components/
for components.The paths must be relative to app, e.g.:
COMPONENTS = ComponentsSettings(\n app_dirs=[\"my_comps\"],\n)\n
To search for
<app>/my_comps/
.These locations are searched during autodiscovery, or when you define HTML, JS, or CSS as separate files.
Set to empty list to disable app-level components:
"},{"location":"reference/settings/#django_components.app_settings.ComponentsSettings.autodiscover","title":"autodiscover","text":"COMPONENTS = ComponentsSettings(\n app_dirs=[],\n)\n
autodiscover: Optional[bool] = None\n
See source code
Toggle whether to run autodiscovery at the Django server startup.
Defaults to
True
"},{"location":"reference/settings/#django_components.app_settings.ComponentsSettings.cache","title":"cache","text":"COMPONENTS = ComponentsSettings(\n autodiscover=False,\n)\n
cache: Optional[str] = None\n
See source code
Name of the Django cache to be used for storing component's JS and CSS files.
If
None
, aLocMemCache
is used with default settings.Defaults to
None
.Read more about caching.
"},{"location":"reference/settings/#django_components.app_settings.ComponentsSettings.context_behavior","title":"context_behavior","text":"COMPONENTS = ComponentsSettings(\n cache=\"my_cache\",\n)\n
context_behavior: Optional[ContextBehaviorType] = None\n
See source code
Configure whether, inside a component template, you can use variables from the outside (
\"django\"
) or not (\"isolated\"
). This also affects what variables are available inside the{% fill %}
tags.Also see Component context and scope.
Defaults to
\"django\"
.COMPONENTS = ComponentsSettings(\n context_behavior=\"isolated\",\n)\n
NOTE:
context_behavior
andslot_context_behavior
options were merged in v0.70.If you are migrating from BEFORE v0.67, set
context_behavior
to\"django\"
. From v0.67 to v0.78 (incl) the default value was\"isolated\"
.For v0.79 and later, the default is again
"},{"location":"reference/settings/#django_components.app_settings.ComponentsSettings.debug_highlight_components","title":"debug_highlight_components","text":"\"django\"
. See the rationale for change here.debug_highlight_components: Optional[bool] = None\n
See source code
Enable / disable component highlighting. See Troubleshooting for more details.
Defaults to
False
.
"},{"location":"reference/settings/#django_components.app_settings.ComponentsSettings.debug_highlight_slots","title":"debug_highlight_slots","text":"COMPONENTS = ComponentsSettings(\n debug_highlight_components=True,\n)\n
debug_highlight_slots: Optional[bool] = None\n
See source code
Enable / disable slot highlighting. See Troubleshooting for more details.
Defaults to
False
.
"},{"location":"reference/settings/#django_components.app_settings.ComponentsSettings.dirs","title":"dirs","text":"COMPONENTS = ComponentsSettings(\n debug_highlight_slots=True,\n)\n
dirs: Optional[Sequence[Union[str, PathLike, Tuple[str, str], Tuple[str, PathLike]]]] = None\n
See source code
Specify the directories that contain your components.
Defaults to
[Path(settings.BASE_DIR) / \"components\"]
. That is, the rootcomponents/
app.Directories must be full paths, same as with STATICFILES_DIRS.
These locations are searched during autodiscovery, or when you define HTML, JS, or CSS as separate files.
COMPONENTS = ComponentsSettings(\n dirs=[BASE_DIR / \"components\"],\n)\n
Set to empty list to disable global components directories:
"},{"location":"reference/settings/#django_components.app_settings.ComponentsSettings.dynamic_component_name","title":"dynamic_component_name","text":"COMPONENTS = ComponentsSettings(\n dirs=[],\n)\n
dynamic_component_name: Optional[str] = None\n
See source code
By default, the dynamic component is registered under the name
\"dynamic\"
.In case of a conflict, you can use this setting to change the component name used for the dynamic components.
# settings.py\nCOMPONENTS = ComponentsSettings(\n dynamic_component_name=\"my_dynamic\",\n)\n
After which you will be able to use the dynamic component with the new name:
"},{"location":"reference/settings/#django_components.app_settings.ComponentsSettings.forbidden_static_files","title":"forbidden_static_files","text":"{% component \"my_dynamic\" is=table_comp data=table_data headers=table_headers %}\n {% fill \"pagination\" %}\n {% component \"pagination\" / %}\n {% endfill %}\n{% endcomponent %}\n
forbidden_static_files: Optional[List[Union[str, Pattern]]] = None\n
See source code
Deprecated. Use
"},{"location":"reference/settings/#django_components.app_settings.ComponentsSettings.libraries","title":"libraries","text":"COMPONENTS.static_files_forbidden
instead.libraries: Optional[List[str]] = None\n
See source code
Configure extra python modules that should be loaded.
This may be useful if you are not using the autodiscovery feature, or you need to load components from non-standard locations. Thus you can have a structure of components that is independent from your apps.
Expects a list of python module paths. Defaults to empty list.
Example:
COMPONENTS = ComponentsSettings(\n libraries=[\n \"mysite.components.forms\",\n \"mysite.components.buttons\",\n \"mysite.components.cards\",\n ],\n)\n
This would be the equivalent of importing these modules from within Django's
AppConfig.ready()
:
"},{"location":"reference/settings/#django_components.app_settings.ComponentsSettings.libraries--manually-loading-libraries","title":"Manually loading libraries","text":"class MyAppConfig(AppConfig):\n def ready(self):\n import \"mysite.components.forms\"\n import \"mysite.components.buttons\"\n import \"mysite.components.cards\"\n
In the rare case that you need to manually trigger the import of libraries, you can use the
import_libraries()
function:
"},{"location":"reference/settings/#django_components.app_settings.ComponentsSettings.multiline_tags","title":"multiline_tags","text":"from django_components import import_libraries\n\nimport_libraries()\n
multiline_tags: Optional[bool] = None\n
See source code
Enable / disable multiline support for template tags. If
True
, template tags like{% component %}
or{{ my_var }}
can span multiple lines.Defaults to
True
.Disable this setting if you are making custom modifications to Django's regular expression for parsing templates at
django.template.base.tag_re
.
"},{"location":"reference/settings/#django_components.app_settings.ComponentsSettings.reload_on_file_change","title":"reload_on_file_change","text":"COMPONENTS = ComponentsSettings(\n multiline_tags=False,\n)\n
reload_on_file_change: Optional[bool] = None\n
See source code
This is relevant if you are using the project structure where HTML, JS, CSS and Python are in separate files and nested in a directory.
In this case you may notice that when you are running a development server, the server sometimes does not reload when you change component files.
Django's native live reload logic handles only Python files and HTML template files. It does NOT reload when other file types change or when template files are nested more than one level deep.
The setting
reload_on_file_change
fixes this, reloading the dev server even when your component's HTML, JS, or CSS changes.If
True
, django_components configures Django to reload when files insideCOMPONENTS.dirs
orCOMPONENTS.app_dirs
change.See Reload dev server on component file changes.
Defaults to
False
.Warning
This setting should be enabled only for the dev environment!
"},{"location":"reference/settings/#django_components.app_settings.ComponentsSettings.reload_on_template_change","title":"reload_on_template_change","text":"reload_on_template_change: Optional[bool] = None\n
See source code
Deprecated. Use
"},{"location":"reference/settings/#django_components.app_settings.ComponentsSettings.static_files_allowed","title":"static_files_allowed","text":"COMPONENTS.reload_on_file_change
instead.static_files_allowed: Optional[List[Union[str, Pattern]]] = None\n
See source code
A list of file extensions (including the leading dot) that define which files within
COMPONENTS.dirs
orCOMPONENTS.app_dirs
are treated as static files.If a file is matched against any of the patterns, it's considered a static file. Such files are collected when running
collectstatic
, and can be accessed under the static file endpoint.You can also pass in compiled regexes (
re.Pattern
) for more advanced patterns.By default, JS, CSS, and common image and font file formats are considered static files:
COMPONENTS = ComponentsSettings(\n static_files_allowed=[\n \".css\",\n \".js\", \".jsx\", \".ts\", \".tsx\",\n # Images\n \".apng\", \".png\", \".avif\", \".gif\", \".jpg\",\n \".jpeg\", \".jfif\", \".pjpeg\", \".pjp\", \".svg\",\n \".webp\", \".bmp\", \".ico\", \".cur\", \".tif\", \".tiff\",\n # Fonts\n \".eot\", \".ttf\", \".woff\", \".otf\", \".svg\",\n ],\n)\n
Warning
Exposing your Python files can be a security vulnerability. See Security notes.
"},{"location":"reference/settings/#django_components.app_settings.ComponentsSettings.static_files_forbidden","title":"static_files_forbidden","text":"static_files_forbidden: Optional[List[Union[str, Pattern]]] = None\n
See source code
A list of file extensions (including the leading dot) that define which files within
COMPONENTS.dirs
orCOMPONENTS.app_dirs
will NEVER be treated as static files.If a file is matched against any of the patterns, it will never be considered a static file, even if the file matches a pattern in
static_files_allowed
.Use this setting together with
static_files_allowed
for a fine control over what file types will be exposed.You can also pass in compiled regexes (
re.Pattern
) for more advanced patterns.By default, any HTML and Python are considered NOT static files:
COMPONENTS = ComponentsSettings(\n static_files_forbidden=[\n \".html\", \".django\", \".dj\", \".tpl\",\n # Python files\n \".py\", \".pyc\",\n ],\n)\n
Warning
Exposing your Python files can be a security vulnerability. See Security notes.
"},{"location":"reference/settings/#django_components.app_settings.ComponentsSettings.tag_formatter","title":"tag_formatter","text":"tag_formatter: Optional[Union[TagFormatterABC, str]] = None\n
See source code
Configure what syntax is used inside Django templates to render components. See the available tag formatters.
Defaults to
\"django_components.component_formatter\"
.Learn more about Customizing component tags with TagFormatter.
Can be set either as direct reference:
from django_components import component_formatter\n\nCOMPONENTS = ComponentsSettings(\n \"tag_formatter\": component_formatter\n)\n
Or as an import string;
COMPONENTS = ComponentsSettings(\n \"tag_formatter\": \"django_components.component_formatter\"\n)\n
Examples:
-
\"django_components.component_formatter\"
Set
COMPONENTS = ComponentsSettings(\n \"tag_formatter\": \"django_components.component_formatter\"\n)\n
To write components like this:
{% component \"button\" href=\"...\" %}\n Click me!\n{% endcomponent %}\n
-
django_components.component_shorthand_formatter
Set
COMPONENTS = ComponentsSettings(\n \"tag_formatter\": \"django_components.component_shorthand_formatter\"\n)\n
To write components like this:
{% button href=\"...\" %}\n Click me!\n{% endbutton %}\n
template_cache_size: Optional[int] = None\n
See source code
Configure the maximum amount of Django templates to be cached.
Defaults to
128
.Each time a Django template is rendered, it is cached to a global in-memory cache (using Python's
lru_cache
decorator). This speeds up the next render of the component. As the same component is often used many times on the same page, these savings add up.By default the cache holds 128 component templates in memory, which should be enough for most sites. But if you have a lot of components, or if you are overriding
Component.get_template()
to render many dynamic templates, you can increase this number.COMPONENTS = ComponentsSettings(\n template_cache_size=256,\n)\n
To remove the cache limit altogether and cache everything, set
template_cache_size
toNone
.COMPONENTS = ComponentsSettings(\n template_cache_size=None,\n)\n
If you want to add templates to the cache yourself, you can use
cached_template()
:
"},{"location":"reference/signals/","title":"Signals","text":""},{"location":"reference/signals/#signals","title":"Signals","text":"from django_components import cached_template\n\ncached_template(\"Variable: {{ variable }}\")\n\n# You can optionally specify Template class, and other Template inputs:\nclass MyTemplate(Template):\n pass\n\ncached_template(\n \"Variable: {{ variable }}\",\n template_cls=MyTemplate,\n name=...\n origin=...\n engine=...\n)\n
Below are the signals that are sent by or during the use of django-components.
"},{"location":"reference/signals/#template_rendered","title":"template_rendered","text":"Django's
template_rendered
signal. This signal is sent when a template is rendered.Django-components triggers this signal when a component is rendered. If there are nested components, the signal is triggered for each component.
Import from django as
django.test.signals.template_rendered
.
"},{"location":"reference/tag_formatters/","title":"Tag formatters","text":""},{"location":"reference/tag_formatters/#tag-formatters","title":"Tag Formatters","text":"from django.test.signals import template_rendered\n\n# Setup a callback function\ndef my_callback(sender, **kwargs):\n ...\n\ntemplate_rendered.connect(my_callback)\n\nclass MyTable(Component):\n template = \"\"\"\n <table>\n <tr>\n <th>Header</th>\n </tr>\n <tr>\n <td>Cell</td>\n </tr>\n \"\"\"\n\n# This will trigger the signal\nMyTable().render()\n
Tag formatters allow you to change the syntax for calling components from within the Django templates.
Tag formatter are set via the tag_formatter setting.
"},{"location":"reference/tag_formatters/#available-tag-formatters","title":"Available tag formatters","text":"-
django_components.component_formatter
for ComponentFormatter -
django_components.component_shorthand_formatter
for ShorthandComponentFormatter
ComponentFormatter
","text":"Bases:
django_components.tag_formatter.TagFormatterABC
See source code
The original django_component's component tag formatter, it uses the
{% component %}
and{% endcomponent %}
tags, and the component name is given as the first positional arg.Example as block:
{% component \"mycomp\" abc=123 %}\n {% fill \"myfill\" %}\n ...\n {% endfill %}\n{% endcomponent %}\n
Example as inlined tag:
"},{"location":"reference/tag_formatters/#django_components.tag_formatter.ShorthandComponentFormatter","title":"{% component \"mycomp\" abc=123 / %}\n
ShorthandComponentFormatter
","text":"Bases:
django_components.tag_formatter.TagFormatterABC
See source code
The component tag formatter that uses
{% <name> %}
/{% end<name> %}
tags.This is similar to django-web-components and django-slippers syntax.
Example as block:
{% mycomp abc=123 %}\n {% fill \"myfill\" %}\n ...\n {% endfill %}\n{% endmycomp %}\n
Example as inlined tag:
"},{"location":"reference/template_tags/","title":"Template tags","text":""},{"location":"reference/template_tags/#template-tags","title":"Template tags","text":"{% mycomp abc=123 / %}\n
All following template tags are defined in
django_components.templatetags.component_tags
Import as
"},{"location":"reference/template_tags/#component_css_dependencies","title":"component_css_dependencies","text":"{% load component_tags %}\n
{% component_css_dependencies %}\n
See source code
Marks location where CSS link tags should be rendered after the whole HTML has been generated.
Generally, this should be inserted into the
<head>
tag of the HTML.If the generated HTML does NOT contain any
{% component_css_dependencies %}
tags, CSS links are by default inserted into the<head>
tag of the HTML. (See JS and CSS output locations)Note that there should be only one
"},{"location":"reference/template_tags/#component_js_dependencies","title":"component_js_dependencies","text":"{% component_css_dependencies %}
for the whole HTML document. If you insert this tag multiple times, ALL CSS links will be duplicately inserted into ALL these places.{% component_js_dependencies %}\n
See source code
Marks location where JS link tags should be rendered after the whole HTML has been generated.
Generally, this should be inserted at the end of the
<body>
tag of the HTML.If the generated HTML does NOT contain any
{% component_js_dependencies %}
tags, JS scripts are by default inserted at the end of the<body>
tag of the HTML. (See JS and CSS output locations)Note that there should be only one
"},{"location":"reference/template_tags/#component","title":"component","text":"{% component_js_dependencies %}
for the whole HTML document. If you insert this tag multiple times, ALL JS scripts will be duplicately inserted into ALL these places.{% component *args: Any, **kwargs: Any [only] %}\n{% endcomponent %}\n
See source code
Renders one of the components that was previously registered with
@register()
decorator.Args:
name
(str, required): Registered name of the component to render- All other args and kwargs are defined based on the component itself.
If you defined a component
\"my_table\"
from django_component import Component, register\n\n@register(\"my_table\")\nclass MyTable(Component):\n template = \"\"\"\n <table>\n <thead>\n {% for header in headers %}\n <th>{{ header }}</th>\n {% endfor %}\n </thead>\n <tbody>\n {% for row in rows %}\n <tr>\n {% for cell in row %}\n <td>{{ cell }}</td>\n {% endfor %}\n </tr>\n {% endfor %}\n <tbody>\n </table>\n \"\"\"\n\n def get_context_data(self, rows: List, headers: List):\n return {\n \"rows\": rows,\n \"headers\": headers,\n }\n
Then you can render this component by referring to
MyTable
via its registered name\"my_table\"
:
"},{"location":"reference/template_tags/#component-input","title":"Component input","text":"{% component \"my_table\" rows=rows headers=headers ... / %}\n
Positional and keyword arguments can be literals or template variables.
The component name must be a single- or double-quotes string and must be either:
-
The first positional argument after
component
:{% component \"my_table\" rows=rows headers=headers ... / %}\n
-
Passed as kwarg
name
:{% component rows=rows headers=headers name=\"my_table\" ... / %}\n
If the component defined any slots, you can pass in the content to be placed inside those slots by inserting
{% fill %}
tags, directly within the{% component %}
tag:
"},{"location":"reference/template_tags/#isolating-components","title":"Isolating components","text":"{% component \"my_table\" rows=rows headers=headers ... / %}\n {% fill \"pagination\" %}\n < 1 | 2 | 3 >\n {% endfill %}\n{% endcomponent %}\n
By default, components behave similarly to Django's
{% include %}
, and the template inside the component has access to the variables defined in the outer template.You can selectively isolate a component, using the
only
flag, so that the inner template can access only the data that was explicitly passed to it:
"},{"location":"reference/template_tags/#fill","title":"fill","text":"{% component \"name\" positional_arg keyword_arg=value ... only %}\n
{% fill name: str, *, data: Optional[str] = None, default: Optional[str] = None %}\n{% endfill %}\n
See source code
Use this tag to insert content into component's slots.
{% fill %}
tag may be used only within a{% component %}..{% endcomponent %}
block. Runtime checks should prohibit other usages.Args:
name
(str, required): Name of the slot to insert this content into. Use\"default\"
for the default slot.default
(str, optional): This argument allows you to access the original content of the slot under the specified variable name. See Accessing original content of slotsdata
(str, optional): This argument allows you to access the data passed to the slot under the specified variable name. See Scoped slots
Examples:
Basic usage:
"},{"location":"reference/template_tags/#accessing-slots-default-content-with-the-default-kwarg","title":"Accessing slot's default content with the{% component \"my_table\" %}\n {% fill \"pagination\" %}\n < 1 | 2 | 3 >\n {% endfill %}\n{% endcomponent %}\n
default
kwarg","text":"{# my_table.html #}\n<table>\n ...\n {% slot \"pagination\" %}\n < 1 | 2 | 3 >\n {% endslot %}\n</table>\n
"},{"location":"reference/template_tags/#accessing-slots-data-with-the-data-kwarg","title":"Accessing slot's data with the{% component \"my_table\" %}\n {% fill \"pagination\" default=\"default_pag\" %}\n <div class=\"my-class\">\n {{ default_pag }}\n </div>\n {% endfill %}\n{% endcomponent %}\n
data
kwarg","text":"{# my_table.html #}\n<table>\n ...\n {% slot \"pagination\" pages=pages %}\n < 1 | 2 | 3 >\n {% endslot %}\n</table>\n
"},{"location":"reference/template_tags/#accessing-slot-data-and-default-content-on-the-default-slot","title":"Accessing slot data and default content on the default slot","text":"{% component \"my_table\" %}\n {% fill \"pagination\" data=\"slot_data\" %}\n {% for page in slot_data.pages %}\n <a href=\"{{ page.link }}\">\n {{ page.index }}\n </a>\n {% endfor %}\n {% endfill %}\n{% endcomponent %}\n
To access slot data and the default slot content on the default slot, use
{% fill %}
withname
set to\"default\"
:
"},{"location":"reference/template_tags/#html_attrs","title":"html_attrs","text":"{% component \"button\" %}\n {% fill name=\"default\" data=\"slot_data\" default=\"default_slot\" %}\n You clicked me {{ slot_data.count }} times!\n {{ default_slot }}\n {% endfill %}\n{% endcomponent %}\n
{% html_attrs attrs: Optional[Dict] = None, defaults: Optional[Dict] = None, **kwargs: Any %}\n
See source code
Generate HTML attributes (
key=\"value\"
), combining data from multiple sources, whether its template variables or static text.It is designed to easily merge HTML attributes passed from outside with the internal. See how to in Passing HTML attributes to components.
Args:
attrs
(dict, optional): Optional dictionary that holds HTML attributes. On conflict, overrides values in thedefault
dictionary.default
(str, optional): Optional dictionary that holds HTML attributes. On conflict, is overriden with values in theattrs
dictionary.- Any extra kwargs will be appended to the corresponding keys
The attributes in
attrs
anddefaults
are merged and resulting dict is rendered as HTML attributes (key=\"value\"
).Extra kwargs (
key=value
) are concatenated to existing keys. So if we haveattrs = {\"class\": \"my-class\"}\n
Then
{% html_attrs attrs class=\"extra-class\" %}\n
will result in
class=\"my-class extra-class\"
.Example:
<div {% html_attrs\n attrs\n defaults:class=\"default-class\"\n class=\"extra-class\"\n data-id=\"123\"\n%}>\n
renders
<div class=\"my-class extra-class\" data-id=\"123\">\n
See more usage examples in HTML attributes.
"},{"location":"reference/template_tags/#provide","title":"provide","text":"{% provide name: str, **kwargs: Any %}\n{% endprovide %}\n
See source code
The \"provider\" part of the provide / inject feature. Pass kwargs to this tag to define the provider's data. Any components defined within the
{% provide %}..{% endprovide %}
tags will be able to access this data withComponent.inject()
.This is similar to React's
ContextProvider
, or Vue'sprovide()
.Args:
name
(str, required): Provider name. This is the name you will then use inComponent.inject()
.**kwargs
: Any extra kwargs will be passed as the provided data.
Example:
Provide the \"user_data\" in parent component:
@register(\"parent\")\nclass Parent(Component):\n template = \"\"\"\n <div>\n {% provide \"user_data\" user=user %}\n {% component \"child\" / %}\n {% endprovide %}\n </div>\n \"\"\"\n\n def get_context_data(self, user: User):\n return {\n \"user\": user,\n }\n
Since the \"child\" component is used within the
{% provide %} / {% endprovide %}
tags, we can request the \"user_data\" usingComponent.inject(\"user_data\")
:@register(\"child\")\nclass Child(Component):\n template = \"\"\"\n <div>\n User is: {{ user }}\n </div>\n \"\"\"\n\n def get_context_data(self):\n user = self.inject(\"user_data\").user\n return {\n \"user\": user,\n }\n
Notice that the keys defined on the
{% provide %}
tag are then accessed as attributes when accessing them withComponent.inject()
.\u2705 Do this
user = self.inject(\"user_data\").user\n
\u274c Don't do this
"},{"location":"reference/template_tags/#slot","title":"slot","text":"user = self.inject(\"user_data\")[\"user\"]\n
{% slot name: str, **kwargs: Any [default] [required] %}\n{% endslot %}\n
See source code
Slot tag marks a place inside a component where content can be inserted from outside.
Learn more about using slots.
This is similar to slots as seen in Web components, Vue or React's
children
.Args:
name
(str, required): Registered name of the component to renderdefault
: Optional flag. If there is a default slot, you can pass the component slot content without using the{% fill %}
tag. See Default slotrequired
: Optional flag. Will raise an error if a slot is required but not given.**kwargs
: Any extra kwargs will be passed as the slot data.
Example:
@register(\"child\")\nclass Child(Component):\n template = \"\"\"\n <div>\n {% slot \"content\" default %}\n This is shown if not overriden!\n {% endslot %}\n </div>\n <aside>\n {% slot \"sidebar\" required / %}\n </aside>\n \"\"\"\n
"},{"location":"reference/template_tags/#passing-data-to-slots","title":"Passing data to slots","text":"@register(\"parent\")\nclass Parent(Component):\n template = \"\"\"\n <div>\n {% component \"child\" %}\n {% fill \"content\" %}\n \ud83d\uddde\ufe0f\ud83d\udcf0\n {% endfill %}\n\n {% fill \"sidebar\" %}\n \ud83c\udf77\ud83e\uddc9\ud83c\udf7e\n {% endfill %}\n {% endcomponent %}\n </div>\n \"\"\"\n
Any extra kwargs will be considered as slot data, and will be accessible in the
{% fill %}
tag via fill'sdata
kwarg:@register(\"child\")\nclass Child(Component):\n template = \"\"\"\n <div>\n {# Passing data to the slot #}\n {% slot \"content\" user=user %}\n This is shown if not overriden!\n {% endslot %}\n </div>\n \"\"\"\n
"},{"location":"reference/template_tags/#accessing-default-slot-content","title":"Accessing default slot content","text":"@register(\"parent\")\nclass Parent(Component):\n template = \"\"\"\n {# Parent can access the slot data #}\n {% component \"child\" %}\n {% fill \"content\" data=\"data\" %}\n <div class=\"wrapper-class\">\n {{ data.user }}\n </div>\n {% endfill %}\n {% endcomponent %}\n \"\"\"\n
The content between the
{% slot %}..{% endslot %}
tags is the default content that will be rendered if no fill is given for the slot.This default content can then be accessed from within the
{% fill %}
tag using the fill'sdefault
kwarg. This is useful if you need to wrap / prepend / append the original slot's content.@register(\"child\")\nclass Child(Component):\n template = \"\"\"\n <div>\n {% slot \"content\" %}\n This is default content!\n {% endslot %}\n </div>\n \"\"\"\n
"},{"location":"reference/template_vars/","title":"Template vars","text":""},{"location":"reference/template_vars/#template-variables","title":"Template variables","text":"@register(\"parent\")\nclass Parent(Component):\n template = \"\"\"\n {# Parent can access the slot's default content #}\n {% component \"child\" %}\n {% fill \"content\" default=\"default\" %}\n {{ default }}\n {% endfill %}\n {% endcomponent %}\n \"\"\"\n
Here is a list of all variables that are automatically available from inside the component's template and in
"},{"location":"reference/template_vars/#django_components.component.ComponentVars.is_filled","title":"is_filledon_render_before
/on_render_after
hooks.instance-attribute
","text":"is_filled: Dict[str, bool]\n
See source code
Dictonary describing which component slots are filled (
True
) or are not (False
).New in version 0.70
Use as
{{ component_vars.is_filled }}
Example:
{# Render wrapping HTML only if the slot is defined #}\n{% if component_vars.is_filled.my_slot %}\n <div class=\"slot-wrapper\">\n {% slot \"my_slot\" / %}\n </div>\n{% endif %}\n
This is equivalent to checking if a given key is among the slot fills:
"},{"location":"reference/urls/","title":"Urls","text":""},{"location":"reference/urls/#urls","title":"URLs","text":"class MyTable(Component):\n def get_context_data(self, *args, **kwargs):\n return {\n \"my_slot_filled\": \"my_slot\" in self.input.slots\n }\n
Below are all the URL patterns that will be added by adding
django_components.urls
.See Installation on how to add these URLs to your Django project.
Django components already prefixes all URLs with
components/
. So when you are adding the URLs tourlpatterns
, you can use an empty string as the first argument:
"},{"location":"reference/urls/#list-of-urls","title":"List of URLs","text":"from django.urls import include, path\n\nurlpatterns = [\n ...\n path(\"\", include(\"django_components.urls\")),\n]\n
-
components/cache/<str:comp_cls_hash>.<str:input_hash>.<str:script_type>
-
components/cache/<str:comp_cls_hash>.<str:script_type>
django-components
combines Django's templating system with the modularity seen in modern frontend frameworks like Vue or React.With
"},{"location":"#quickstart","title":"Quickstart","text":"django-components
you can support Django projects small and large without leaving the Django ecosystem.A component in django-components can be as simple as a Django template and Python code to declare the component:
components/calendar/calendar.html
components/calendar/calendar.py<div class=\"calendar\">\n Today's date is <span>{{ date }}</span>\n</div>\n
from django_components import Component\n\nclass Calendar(Component):\n template_file = \"calendar.html\"\n
Or a combination of Django template, Python, CSS, and Javascript:
components/calendar/calendar.html
components/calendar/calendar.css<div class=\"calendar\">\n Today's date is <span>{{ date }}</span>\n</div>\n
components/calendar/calendar.js.calendar {\n width: 200px;\n background: pink;\n}\n
components/calendar/calendar.pydocument.querySelector(\".calendar\").onclick = function () {\n alert(\"Clicked calendar!\");\n};\n
from django_components import Component\n\nclass Calendar(Component):\n template_file = \"calendar.html\"\n js_file = \"calendar.js\"\n css_file = \"calendar.css\"\n\n def get_context_data(self, date):\n return {\"date\": date}\n
Use the component like this:
{% component \"calendar\" date=\"2024-11-06\" %}{% endcomponent %}\n
And this is what gets rendered:
<div class=\"calendar-component\">\n Today's date is <span>2024-11-06</span>\n</div>\n
Read on to learn about all the exciting details and configuration possibilities!
(If you instead prefer to jump right into the code, check out the example project)
"},{"location":"#features","title":"Features","text":""},{"location":"#modern-and-modular-ui","title":"Modern and modular UI","text":"- Create self-contained, reusable UI elements.
- Each component can include its own HTML, CSS, and JS, or additional third-party JS and CSS.
- HTML, CSS, and JS can be defined on the component class, or loaded from files.
"},{"location":"#composition-with-slots","title":"Composition with slots","text":"from django_components import Component\n\n@register(\"calendar\")\nclass Calendar(Component):\n template = \"\"\"\n <div class=\"calendar\">\n Today's date is\n <span>{{ date }}</span>\n </div>\n \"\"\"\n\n css = \"\"\"\n .calendar {\n width: 200px;\n background: pink;\n }\n \"\"\"\n\n js = \"\"\"\n document.querySelector(\".calendar\")\n .addEventListener(\"click\", () => {\n alert(\"Clicked calendar!\");\n });\n \"\"\"\n\n # Additional JS and CSS\n class Media:\n js = [\"https://cdn.jsdelivr.net/npm/htmx.org@2.1.1/dist/htmx.min.js\"]\n css = [\"bootstrap/dist/css/bootstrap.min.css\"]\n\n # Variables available in the template\n def get_context_data(self, date):\n return {\n \"date\": date\n }\n
- Render components inside templates with
{% component %}
tag. - Compose them with
{% slot %}
and{% fill %}
tags. - Vue-like slot system, including scoped slots.
"},{"location":"#extended-template-tags","title":"Extended template tags","text":"{% component \"Layout\"\n bookmarks=bookmarks\n breadcrumbs=breadcrumbs\n%}\n {% fill \"header\" %}\n <div class=\"flex justify-between gap-x-12\">\n <div class=\"prose\">\n <h3>{{ project.name }}</h3>\n </div>\n <div class=\"font-semibold text-gray-500\">\n {{ project.start_date }} - {{ project.end_date }}\n </div>\n </div>\n {% endfill %}\n\n {# Access data passed to `{% slot %}` with `data` #}\n {% fill \"tabs\" data=\"tabs_data\" %}\n {% component \"TabItem\" header=\"Project Info\" %}\n {% component \"ProjectInfo\"\n project=project\n project_tags=project_tags\n attrs:class=\"py-5\"\n attrs:width=tabs_data.width\n / %}\n {% endcomponent %}\n {% endfill %}\n{% endcomponent %}\n
django-components
extends Django's template tags syntax with:- Literal lists and dictionaries in template tags
- Self-closing tags
{% mytag / %}
- Multi-line template tags
- Spread operator
...
to dynamically pass args or kwargs into the template tag - Nested template tags like
\"{{ first_name }} {{ last_name }}\"
- Flat definition of dictionary keys
attr:key=val
"},{"location":"#html-fragment-support","title":"HTML fragment support","text":"{% component \"table\"\n ...default_attrs\n title=\"Friend list for {{ user.name }}\"\n headers=[\"Name\", \"Age\", \"Email\"]\n data=[\n {\n \"name\": \"John\"|upper,\n \"age\": 30|add:1,\n \"email\": \"john@example.com\",\n \"hobbies\": [\"reading\"],\n },\n {\n \"name\": \"Jane\"|upper,\n \"age\": 25|add:1,\n \"email\": \"jane@example.com\",\n \"hobbies\": [\"reading\", \"coding\"],\n },\n ],\n attrs:class=\"py-4 ma-2 border-2 border-gray-300 rounded-md\"\n/ %}\n
django-components
makes intergration with HTMX, AlpineJS or jQuery easy by allowing components to be rendered as HTML fragments:-
Components's JS and CSS is loaded automatically when the fragment is inserted into the DOM
-
Expose components as views with
get
,post
,put
,patch
,delete
methods
"},{"location":"#type-hints","title":"Type hints","text":"# components/calendar/calendar.py\n@register(\"calendar\")\nclass Calendar(Component):\n template_file = \"calendar.html\"\n\n def get(self, request, *args, **kwargs):\n page = request.GET.get(\"page\", 1)\n return self.render_to_response(\n kwargs={\n \"page\": page,\n }\n )\n\n def get_context_data(self, page):\n return {\n \"page\": page,\n }\n\n# urls.py\npath(\"calendar/\", Calendar.as_view()),\n
Opt-in to type hints by defining types for component's args, kwargs, slots, and more:
from typing import NotRequired, Tuple, TypedDict, SlotContent, SlotFunc\n\nButtonArgs = Tuple[int, str]\n\nclass ButtonKwargs(TypedDict):\n variable: str\n another: int\n maybe_var: NotRequired[int] # May be omitted\n\nclass ButtonData(TypedDict):\n variable: str\n\nclass ButtonSlots(TypedDict):\n my_slot: NotRequired[SlotFunc]\n another_slot: SlotContent\n\nButtonType = Component[ButtonArgs, ButtonKwargs, ButtonSlots, ButtonData, JsData, CssData]\n\nclass Button(ButtonType):\n def get_context_data(self, *args, **kwargs):\n self.input.args[0] # int\n self.input.kwargs[\"variable\"] # str\n self.input.slots[\"my_slot\"] # SlotFunc[MySlotData]\n\n return {} # Error: Key \"variable\" is missing\n
When you then call
Button.render()
orButton.render_to_response()
, you will get type hints:
"},{"location":"#debugging-features","title":"Debugging features","text":"Button.render(\n # Error: First arg must be `int`, got `float`\n args=(1.25, \"abc\"),\n # Error: Key \"another\" is missing\n kwargs={\n \"variable\": \"text\",\n },\n)\n
- Visual component inspection: Highlight components and slots directly in your browser.
- Detailed tracing logs to supply AI-agents with context: The logs include component and slot names and IDs, and their position in the tree.
- Install and use third-party components from PyPI
- Or publish your own \"component registry\"
-
Highly customizable - Choose how the components are called in the template (and more):
{% component \"calendar\" date=\"2024-11-06\" %}\n{% endcomponent %}\n\n{% calendar date=\"2024-11-06\" %}\n{% endcalendar %}\n
- Vue-like provide / inject system
- Format HTML attributes with
{% html_attrs %}
Read the Release Notes to see the latest features and fixes.
"},{"location":"#community-examples","title":"Community examples","text":"One of our goals with
"},{"location":"#contributing-and-development","title":"Contributing and development","text":"django-components
is to make it easy to share components between projects. Head over to the Community examples to see some examples.Get involved or sponsor this project - See here
Running django-components locally for development - See here
"},{"location":"SUMMARY/","title":"SUMMARY","text":"- Overview
- Getting Started
- Concepts
- Fundamentals
- Advanced
- Guides
- Setup
- Other
- Dev guides
- API Documentation
- Release notes
This guide is for you if you're upgrating django_components to v0.100 or later from older versions.
In version 0.100, we changed how components' static JS and CSS files are handled. See more in the \"Static files\" section.
Migration steps:
- Remove
django_components.safer_staticfiles
fromINSTALLED_APPS
in yoursettings.py
, and replace it withdjango.contrib.staticfiles
.
Before:
INSTALLED_APPS = [\n \"django.contrib.admin\",\n ...\n # \"django.contrib.staticfiles\", # <-- ADD\n \"django_components\",\n \"django_components.safer_staticfiles\", # <-- REMOVE\n]\n
After:
INSTALLED_APPS = [\n \"django.contrib.admin\",\n ...\n \"django.contrib.staticfiles\",\n \"django_components\",\n]\n
- Add
STATICFILES_FINDERS
tosettings.py
, and adddjango_components.finders.ComponentsFileSystemFinder
:
STATICFILES_FINDERS = [\n # Default finders\n \"django.contrib.staticfiles.finders.FileSystemFinder\",\n \"django.contrib.staticfiles.finders.AppDirectoriesFinder\",\n # Django components\n \"django_components.finders.ComponentsFileSystemFinder\", # <-- ADDED\n]\n
- Add
COMPONENTS.dirs
tosettings.py
.
If you previously defined
STATICFILES_DIRS
, move only those directories fromSTATICFILES_DIRS
that point to components directories, and keep the rest.E.g. if you have
STATICFILES_DIRS
like this:STATICFILES_DIRS = [\n BASE_DIR / \"components\", # <-- MOVE\n BASE_DIR / \"myapp\" / \"components\", # <-- MOVE\n BASE_DIR / \"assets\",\n]\n
Then first two entries point to components dirs, whereas
/assets
points to non-component static files. In this case move only the first two paths:COMPONENTS = {\n \"dirs\": [\n BASE_DIR / \"components\", # <-- MOVED\n BASE_DIR / \"myapp\" / \"components\", # <-- MOVED\n ],\n}\n\nSTATICFILES_DIRS = [\n BASE_DIR / \"assets\",\n]\n
Moreover, if you defined app-level component directories in
STATICFILES_DIRS
before, you can now define as a RELATIVE path inapp_dirs
:
"},{"location":"release_notes/","title":"Release notes","text":""},{"location":"release_notes/#v0129","title":"v0.129","text":""},{"location":"release_notes/#fix","title":"Fix","text":"COMPONENTS = {\n \"dirs\": [\n # Search top-level \"/components/\" dir\n BASE_DIR / \"components\",\n ],\n \"app_dirs\": [\n # Search \"/[app]/components/\" dirs\n \"components\",\n ],\n}\n\nSTATICFILES_DIRS = [\n BASE_DIR / \"assets\",\n]\n
- Fix thread unsafe media resolve validation by moving it to ComponentMedia
__post_init
(#977 - Fix bug: Relative path in extends and include does not work when using template_file (#976
- Fix error when template cache setting (
template_cache_size
) is set to 0 (#974
-
Configurable cache - Set
COMPONENTS.cache
to change where and how django-components caches JS and CSS files. (#946)Read more on Caching.
-
Highlight coponents and slots in the UI - We've added two boolean settings
COMPONENTS.debug_highlight_components
andCOMPONENTS.debug_highlight_slots
, which can be independently set toTrue
. First will wrap components in a blue border, the second will wrap slots in a red border. (#942)Read more on Troubleshooting.
- Removed use of eval for node validation (#944)
-
Components can now be infinitely nested. (#936)
-
Component input validation is now 6-7x faster on CPython and PyPy. This previously made up 10-30% of the total render time. (#945)
- Fix component rendering when using
{% cache %}
with remote cache and multiple web servers (#930)
- Replaced BeautifulSoup4 with a custom HTML parser.
- The heuristic for inserting JS and CSS dependenies into the default place has changed.
- JS is still inserted at the end of the
<body>
, and CSS at the end of<head>
. - However, we find end of
<body>
by searching for last occurrence of</body>
- And for the end of
<head>
we search for the first occurrence of</head>
- JS is still inserted at the end of the
\u26a0\ufe0f Attention \u26a0\ufe0f - We migrated from
EmilStenstrom/django-components
todjango-components/django-components
.Repo name and documentation URL changed. Package name remains the same.
If you see any broken links or other issues, please report them in #922.
"},{"location":"release_notes/#feat_1","title":"Feat","text":"@template_tag
andBaseNode
- A decorator and a class that allow you to define custom template tags that will behave similarly to django-components' own template tags.
Read more on Template tags.
Template tags defined with
@template_tag
andBaseNode
will have the following features:-
Accepting args, kwargs, and flags.
-
Allowing literal lists and dicts as inputs as:
key=[1, 2, 3]
orkey={\"a\": 1, \"b\": 2}
- Using template tags tag inputs as:{% my_tag key=\"{% lorem 3 w %}\" / %}
- Supporting the flat dictionary definition:attr:key=value
- Spreading args and kwargs with...
:{% my_tag ...args ...kwargs / %}
- Being able to call the template tag as:{% my_tag %} ... {% endmy_tag %}
or{% my_tag / %}
-
Refactored template tag input validation. When you now call template tags like
{% slot %}
,{% fill %}
,{% html_attrs %}
, and others, their inputs are now validated the same way as Python function inputs are.So, for example
{% slot \"my_slot\" name=\"content\" / %}\n
will raise an error, because the positional argument
name
is given twice.NOTE: Special kwargs whose keys are not valid Python variable names are not affected by this change. So when you define:
{% component data-id=123 / %}\n
The
data-id
will still be accepted as a valid kwarg, assuming that yourget_context_data()
accepts**kwargs
:def get_context_data(self, **kwargs):\n return {\n \"data_id\": kwargs[\"data-id\"],\n }\n
-
Instead of inlining the JS and CSS under
Component.js
andComponent.css
, you can move them to their own files, and link the JS/CSS files withComponent.js_file
andComponent.css_file
.Even when you specify the JS/CSS with
Component.js_file
orComponent.css_file
, then you can still access the content underComponent.js
orComponent.css
- behind the scenes, the content of the JS/CSS files will be set toComponent.js
/Component.css
upon first access.The same applies to
Component.template_file
, which will populateComponent.template
upon first access.With this change, the role of
Component.js/css
and the JS/CSS inComponent.Media
has changed:- The JS/CSS defined in
Component.js/css
orComponent.js/css_file
is the \"main\" JS/CSS - The JS/CSS defined in
Component.Media.js/css
are secondary or additional
See the updated \"Getting Started\" tutorial
- The JS/CSS defined in
-
The canonical way to define a template file was changed from
template_name
totemplate_file
, to align with the rest of the API.template_name
remains for backwards compatibility. When you get / settemplate_name
, internally this is proxied totemplate_file
. -
The undocumented
Component.component_id
was removed. Instead, useComponent.id
. Changes:- While
component_id
was unique every time you instantiatedComponent
, the newid
is unique every time you render the component (e.g. withComponent.render()
) - The new
id
is available only during render, so e.g. from withinget_context_data()
- While
-
Component's HTML / CSS / JS are now resolved and loaded lazily. That is, if you specify
template_name
/template_file
,js_file
,css_file
, orMedia.js/css
, the file paths will be resolved only once you:- Try to access component's HTML / CSS / JS, or
- Render the component.
Read more on Accessing component's HTML / JS / CSS.
-
Component inheritance:
- When you subclass a component, the JS and CSS defined on parent's
Media
class is now inherited by the child component. - You can disable or customize Media inheritance by setting
extend
attribute on theComponent.Media
nested class. This work similarly to Django'sMedia.extend
. - When child component defines either
template
ortemplate_file
, both of parent'stemplate
andtemplate_file
are ignored. The same applies tojs_file
andcss_file
.
- When you subclass a component, the JS and CSS defined on parent's
-
Autodiscovery now ignores files and directories that start with an underscore (
_
), except__init__.py
-
The Signals emitted by or during the use of django-components are now documented, together the
template_rendered
signal.
- Fix edge cases around rendering components whose templates used the
{% extends %}
template tag (#859)
- Add support for HTML fragments. HTML fragments can be rendered by passing
type=\"fragment\"
toComponent.render()
orComponent.render_to_response()
. Read more on how to use HTML fragments with HTMX, AlpineJS, or vanillaJS.
- Fix the use of Django template filters (
|lower:\"etc\"
) with component inputs #855.
\u26a0\ufe0f Attention \u26a0\ufe0f - Please update to v0.121 to fix bugs introduced in v0.119.
"},{"location":"release_notes/#fix_4","title":"Fix","text":"- Fix the use of translation strings
_(\"bla\")
as inputs to components #849.
\u26a0\ufe0f Attention \u26a0\ufe0f - This release introduced bugs #849, #855. Please update to v0.121.
"},{"location":"release_notes/#fix_5","title":"Fix","text":"- Fix compatibility with custom subclasses of Django's
Template
that need to accessorigin
or other initialization arguments. (https://github.com/django-components/django-components/pull/828)
- Compatibility with
django-debug-toolbar-template-profiler
: -
Monkeypatching of Django's
Template
now happens atAppConfig.ready()
(https://github.com/django-components/django-components/pull/825) -
Internal parsing of template tags tag was updated. No API change. (https://github.com/django-components/django-components/pull/827)
- Add support for
context_processors
andRenderContext
inside component templates
Component.render()
andComponent.render_to_response()
now accept an extra kwargrequest
.```py\ndef my_view(request)\n return MyTable.render_to_response(\n request=request\n )\n```\n
-
When you pass in
request
, the component will useRenderContext
instead ofContext
. Thus the context processors will be applied to the context. -
NOTE: When you pass in both
request
andcontext
toComponent.render()
, andcontext
is already an instance ofContext
, therequest
kwarg will be ignored.
- The HTML parser no longer erronously inserts
<html><head><body>
on some occasions, and no longer tries to close unclosed HTML tags.
- Replaced Selectolax with BeautifulSoup4 as project dependencies.
\u26a0\ufe0f Attention \u26a0\ufe0f - Please update to v0.117 to fix known bugs. See #791 and #789 and #818.
"},{"location":"release_notes/#fix_7","title":"Fix","text":"- Fix the order of execution of JS scripts:
- Scripts in
Component.Media.js
are executed in the order they are defined -
Scripts in
Component.js
are executed AFTERMedia.js
scripts -
Fix compatibility with AlpineJS
- Scripts in
Component.Media.js
are now again inserted as<script>
tags - By default,
Component.Media.js
are inserted as synchronous<script>
tags, so the AlpineJS components registered in theMedia.js
scripts will now again run BEFORE the core AlpineJS script.
AlpineJS can be configured like so:
Option 1 - AlpineJS loaded in
<head>
withdefer
attribute:<html>\n <head>\n {% component_css_dependencies %}\n <script defer src=\"https://unpkg.com/alpinejs\"></script>\n </head>\n <body>\n {% component 'my_alpine_component' / %}\n {% component_js_dependencies %}\n </body>\n</html>\n
Option 2 - AlpineJS loaded in
<body>
AFTER{% component_js_depenencies %}
:
"},{"location":"release_notes/#v0115","title":"v0.115","text":"<html>\n <head>\n {% component_css_dependencies %}\n </head>\n <body>\n {% component 'my_alpine_component' / %}\n {% component_js_dependencies %}\n\n <script src=\"https://unpkg.com/alpinejs\"></script>\n </body>\n</html>\n
\u26a0\ufe0f Attention \u26a0\ufe0f - Please update to v0.117 to fix known bugs. See #791 and #789 and #818.
"},{"location":"release_notes/#fix_8","title":"Fix","text":"- Fix integration with ManifestStaticFilesStorage on Windows by resolving component filepaths (like
Component.template_name
) to POSIX paths.
\u26a0\ufe0f Attention \u26a0\ufe0f - Please update to v0.117 to fix known bugs. See #791 and #789 and #818.
"},{"location":"release_notes/#fix_9","title":"Fix","text":"- Prevent rendering Slot tags during fill discovery stage to fix a case when a component inside a slot fill tried to access provided data too early.
\u26a0\ufe0f Attention \u26a0\ufe0f - Please update to v0.117 to fix known bugs. See #791 and #789 and #818.
"},{"location":"release_notes/#fix_10","title":"Fix","text":"- Ensure consistent order of scripts in
Component.Media.js
\u26a0\ufe0f Attention \u26a0\ufe0f - Please update to v0.117 to fix known bugs. See #791 and #789 and #818.
"},{"location":"release_notes/#fix_11","title":"Fix","text":"- Allow components to accept default fill even if no default slot was encountered during rendering
\u26a0\ufe0f Attention \u26a0\ufe0f - Please update to v0.117 to fix known bugs. See #791 and #789 and #818.
"},{"location":"release_notes/#fix_12","title":"Fix","text":"- Prevent rendering Component tags during fill discovery stage to fix a case when a component inside the default slot tried to access provided data too early.
\u26a0\ufe0f Attention \u26a0\ufe0f - Please update to v0.117 to fix known bugs. See #791 and #789 and #818.
"},{"location":"release_notes/#general","title":"General","text":""},{"location":"release_notes/#breaking-changes","title":"\ud83d\udea8\ud83d\udce2 BREAKING CHANGES","text":"-
Installation changes:
- If your components include JS or CSS, you now must use the middleware and add django-components' URLs to your
urlpatterns
(See \"Adding support for JS and CSS\")
- If your components include JS or CSS, you now must use the middleware and add django-components' URLs to your
-
Component typing signature changed from
Component[Args, Kwargs, Data, Slots]\n
to
Component[Args, Kwargs, Slots, Data, JsData, CssData]\n
-
If you rendered a component A with
Component.render()
and then inserted that into another component B, now you must passrender_dependencies=False
to component A:prerendered_a = CompA.render(\n args=[...],\n kwargs={...},\n render_dependencies=False,\n)\n\nhtml = CompB.render(\n kwargs={\n content=prerendered_a,\n },\n)\n
- Intellisense and mypy validation for settings:
Instead of defining the
COMPONENTS
settings as a plain dict, you can useComponentsSettings
:# settings.py\nfrom django_components import ComponentsSettings\n\nCOMPONENTS = ComponentsSettings(\n autodiscover=True,\n ...\n)\n
- Use
get_component_dirs()
andget_component_files()
to get the same list of dirs / files that would be imported byautodiscover()
, but without actually importing them.
-
For advanced use cases, use can omit the middleware and instead manage component JS and CSS dependencies yourself with
render_dependencies
-
The
ComponentRegistry
settingsRegistrySettings
were lowercased to align with the global settings: RegistrySettings.CONTEXT_BEHAVIOR
->RegistrySettings.context_behavior
RegistrySettings.TAG_FORMATTER
->RegistrySettings.tag_formatter
The old uppercase settings
CONTEXT_BEHAVIOR
andTAG_FORMATTER
are deprecated and will be removed in v1.-
The setting
reload_on_template_change
was renamed toreload_on_file_change
. And now it properly triggers server reload when any file in the component dirs change. The old namereload_on_template_change
is deprecated and will be removed in v1. -
The setting
forbidden_static_files
was renamed tostatic_files_forbidden
to align withstatic_files_allowed
The old nameforbidden_static_files
is deprecated and will be removed in v1.
-
{% component_dependencies %}
tag was removed. Instead, use{% component_js_dependencies %}
and{% component_css_dependencies %}
-
The combined tag was removed to encourage the best practice of putting JS scripts at the end of
<body>
, and CSS styles inside<head>
.On the other hand, co-locating JS script and CSS styles can lead to a flash of unstyled content, as either JS scripts will block the rendering, or CSS will load too late.
-
-
The undocumented keyword arg
preload
of{% component_js_dependencies %}
and{% component_css_dependencies %}
tags was removed. This will be replaced with HTML fragment support.
- Allow using forward slash (
/
) when defining custom TagFormatter, e.g.{% MyComp %}..{% /MyComp %}
.
{% component_dependencies %}
tags are now OPTIONAL - If your components use JS and CSS, but you don't use{% component_dependencies %}
tags, the JS and CSS will now be, by default, inserted at the end of<body>
and at the end of<head>
respectively.
- Fills can now be defined within loops (
{% for %}
) or other tags (like{% with %}
), or even other templates using{% include %}
.
Following is now possible
{% component \"table\" %}\n {% for slot_name in slots %}\n {% fill name=slot_name %}\n {% endfill %}\n {% endfor %}\n{% endcomponent %}\n
- If you need to access the data or the default content of a default fill, you can set the
name
kwarg to\"default\"
.
Previously, a default fill would be defined simply by omitting the
{% fill %}
tags:{% component \"child\" %}\n Hello world\n{% endcomponent %}\n
But in that case you could not access the slot data or the default content, like it's possible for named fills:
{% component \"child\" %}\n {% fill name=\"header\" data=\"data\" %}\n Hello {{ data.user.name }}\n {% endfill %}\n{% endcomponent %}\n
Now, you can specify default tag by using
name=\"default\"
:{% component \"child\" %}\n {% fill name=\"default\" data=\"data\" %}\n Hello {{ data.user.name }}\n {% endfill %}\n{% endcomponent %}\n
- When inside
get_context_data()
or other component methods, the default fill can now be accessed asComponent.input.slots[\"default\"]
, e.g.:
class MyTable(Component):\n def get_context_data(self, *args, **kwargs):\n default_slot = self.input.slots[\"default\"]\n ...\n
- You can now dynamically pass all slots to a child component. This is similar to passing all slots in Vue:
"},{"location":"release_notes/#fix_14","title":"Fix","text":"class MyTable(Component):\n def get_context_data(self, *args, **kwargs):\n return {\n \"slots\": self.input.slots,\n }\n\n template: \"\"\"\n <div>\n {% component \"child\" %}\n {% for slot_name in slots %}\n {% fill name=slot_name data=\"data\" %}\n {% slot name=slot_name ...data / %}\n {% endfill %}\n {% endfor %}\n {% endcomponent %}\n </div>\n \"\"\"\n
-
Slots defined with
{% fill %}
tags are now properly accessible viaself.input.slots
inget_context_data()
-
Do not raise error if multiple slots with same name are flagged as default
-
Slots can now be defined within loops (
{% for %}
) or other tags (like{% with %}
), or even other templates using{% include %}
.
Previously, following would cause the kwarg
name
to be an empty string:
"},{"location":"release_notes/#refactor_8","title":"Refactor","text":"{% for slot_name in slots %}\n {% slot name=slot_name %}\n{% endfor %}\n
- When you define multiple slots with the same name inside a template, you now have to set the
default
andrequired
flags individually.
<div class=\"calendar-component\">\n <div class=\"header\">\n {% slot \"image\" default required %}Image here{% endslot %}\n </div>\n <div class=\"body\">\n {% slot \"image\" default required %}Image here{% endslot %}\n </div>\n</div>\n
This means you can also have multiple slots with the same name but different conditions.
E.g. in this example, we have a component that renders a user avatar - a small circular image with a profile picture of name initials.
If the component is given
image_src
orname_initials
variables, theimage
slot is optional. But if neither of those are provided, you MUST fill theimage
slot.<div class=\"avatar\">\n {% if image_src %}\n {% slot \"image\" default %}\n <img src=\"{{ image_src }}\" />\n {% endslot %}\n {% elif name_initials %}\n {% slot \"image\" default required %}\n <div style=\"\n border-radius: 25px;\n width: 50px;\n height: 50px;\n background: blue;\n \">\n {{ name_initials }}\n </div>\n {% endslot %}\n {% else %}\n {% slot \"image\" default required / %}\n {% endif %}\n</div>\n
- The slot fills that were passed to a component and which can be accessed as
Component.input.slots
can now be passed through the Django template, e.g. as inputs to other tags.
Internally, django-components handles slot fills as functions.
Previously, if you tried to pass a slot fill within a template, Django would try to call it as a function.
Now, something like this is possible:
class MyTable(Component):\n def get_context_data(self, *args, **kwargs):\n return {\n \"child_slot\": self.input.slots[\"child_slot\"],\n }\n\n template: \"\"\"\n <div>\n {% component \"child\" content=child_slot / %}\n </div>\n \"\"\"\n
NOTE: Using
{% slot %}
and{% fill %}
tags is still the preferred method, but the approach above may be necessary in some complex or edge cases.- The
is_filled
variable (and the{{ component_vars.is_filled }}
context variable) now returnsFalse
when you try to access a slot name which has not been defined:
Before:
{{ component_vars.is_filled.header }} -> True\n{{ component_vars.is_filled.footer }} -> False\n{{ component_vars.is_filled.nonexist }} -> \"\" (empty string)\n
After:
{{ component_vars.is_filled.header }} -> True\n{{ component_vars.is_filled.footer }} -> False\n{{ component_vars.is_filled.nonexist }} -> False\n
-
Components no longer raise an error if there are extra slot fills
-
Components will raise error when a slot is doubly-filled.
E.g. if we have a component with a default slot:
{% slot name=\"content\" default / %}\n
Now there is two ways how we can target this slot: Either using
name=\"default\"
orname=\"content\"
.In case you specify BOTH, the component will raise an error:
"},{"location":"release_notes/#v0100","title":"\ud83d\udea8\ud83d\udce2 v0.100","text":""},{"location":"release_notes/#breaking-changes_2","title":"BREAKING CHANGES","text":"{% component \"child\" %}\n {% fill slot=\"default\" %}\n Hello from default slot\n {% endfill %}\n {% fill slot=\"content\" data=\"data\" %}\n Hello from content slot\n {% endfill %}\n{% endcomponent %}\n
-
django_components.safer_staticfiles
app was removed. It is no longer needed. -
Installation changes:
- Instead of defining component directories in
STATICFILES_DIRS
, set them toCOMPONENTS.dirs
. -
You now must define
STATICFILES_FINDERS
-
See here how to migrate your settings.py
- Instead of defining component directories in
- Beside the top-level
/components
directory, you can now define also app-level components dirs, e.g.[app]/components
(SeeCOMPONENTS.app_dirs
).
- When you call
as_view()
on a component instance, that instance will be passed toView.as_view()
- Fixed template caching. You can now also manually create cached templates with
cached_template()
-
The previously undocumented
get_template
was made private. -
In it's place, there's a new
get_template
, which supersedesget_template_string
(will be removed in v1). The newget_template
is the same asget_template_string
, except it allows to return either a string or a Template instance. -
You now must use only one of
template
,get_template
,template_name
, orget_template_name
.
-
Run-time type validation for Python 3.11+ - If the
Component
class is typed, e.g.Component[Args, Kwargs, ...]
, the args, kwargs, slots, and data are validated against the given types. (See Runtime input validation with types) -
Render hooks - Set
on_render_before
andon_render_after
methods onComponent
to intercept or modify the template or context before rendering, or the rendered result afterwards. (See Component hooks) -
component_vars.is_filled
context variable can be accessed from withinon_render_before
andon_render_after
hooks asself.is_filled.my_slot
- Added support for dynamic components, where the component name is passed as a variable. (See Dynamic components)
- Changed
Component.input
to raiseRuntimeError
if accessed outside of render context. Previously it returnedNone
if unset.
-
django_components now automatically configures Django to support multi-line tags. (See Multi-line tags)
-
New setting
reload_on_template_change
. Set this toTrue
to reload the dev server on changes to component template files. (See Reload dev server on component file changes)
-
Spread operator
...dict
inside template tags. (See Spread operator) -
Use template tags inside string literals in component inputs. (See Use template tags inside component inputs)
-
Dynamic slots, fills and provides - The
name
argument for these can now be a variable, a template expression, or via spread operator -
Component library authors can now configure
CONTEXT_BEHAVIOR
andTAG_FORMATTER
settings independently from user settings.
Component
class is no longer a subclass ofView
. To configure theView
class, set theComponent.View
nested class. HTTP methods likeget
orpost
can still be defined directly onComponent
class, andComponent.as_view()
internally callsComponent.View.as_view()
. (See Modifying the View class)
-
The inputs (args, kwargs, slots, context, ...) that you pass to
Component.render()
can be accessed from withinget_context_data
,get_template
andget_template_name
viaself.input
. (See Accessing data passed to the component) -
Typing:
Component
class supports generics that specify types forComponent.render
(See Adding type hints with Generics)
-
All tags (
component
,slot
,fill
, ...) now support \"self-closing\" or \"inline\" form, where you can omit the closing tag:{# Before #}\n{% component \"button\" %}{% endcomponent %}\n{# After #}\n{% component \"button\" / %}\n
-
All tags now support the \"dictionary key\" or \"aggregate\" syntax (
kwarg:key=val
):{% component \"button\" attrs:class=\"hidden\" %}\n
-
You can change how the components are written in the template with TagFormatter.
The default is
django_components.component_formatter
:{% component \"button\" href=\"...\" disabled %}\n Click me!\n{% endcomponent %}\n
While
django_components.shorthand_component_formatter
allows you to write components like so:{% button href=\"...\" disabled %}\n Click me!\n{% endbutton %}\n
-
Autodiscovery module resolution changed. Following undocumented behavior was removed:
-
Previously, autodiscovery also imported any
[app]/components.py
files, and usedSETTINGS_MODULE
to search for component dirs.To migrate from:
-
[app]/components.py
- Define each module inCOMPONENTS.libraries
setting, or import each module inside theAppConfig.ready()
hook in respectiveapps.py
files. -
SETTINGS_MODULE
- Define component dirs usingSTATICFILES_DIRS
-
-
Previously, autodiscovery handled relative files in
STATICFILES_DIRS
. To align with Django,STATICFILES_DIRS
now must be full paths (Django docs).
-
- The order of arguments to
render_to_response
has changed, to align with the (now public)render
method ofComponent
class.
-
Component.render()
is public and documented -
Slots passed
render_to_response
andrender
can now be rendered also as functions.
- Vue-like provide/inject with the
{% provide %}
tag andinject()
method.
- Default value for the
COMPONENTS.context_behavior
setting was changes from\"isolated\"
to\"django\"
. If you did not set this value explicitly before, this may be a breaking change. See the rationale for change here.
-
The syntax for accessing default slot content has changed from
{% fill \"my_slot\" as \"alias\" %}\n {{ alias.default }}\n{% endfill %}\n
to
{% fill \"my_slot\" default=\"alias\" %}\n {{ alias }}\n{% endfill %}\n
-
{% html_attrs %}
tag for formatting data as HTML attributes -
prefix:key=val
construct for passing dicts to components
-
{% if_filled \"my_slot\" %}
tags were replaced with{{ component_vars.is_filled.my_slot }}
variables. -
Simplified settings -
slot_context_behavior
andcontext_behavior
were merged. See the documentation for more details.
- Changed the default way how context variables are resolved in slots. See the documentation for more details.
-
{% component_block %}
is now{% component %}
, and{% component %}
blocks need an ending{% endcomponent %}
tag.The new
python manage.py upgradecomponent
command can be used to upgrade a directory (use--path
argument to point to each dir) of templates that use components to the new syntax automatically.This change is done to simplify the API in anticipation of a 1.0 release of django_components. After 1.0 we intend to be stricter with big changes like this in point releases.
- Components as views, which allows you to handle requests and render responses from within a component. See the documentation for more details.
- 'implicit' slot filling and the
default
option forslot
tags.
- A second installable app
django_components.safer_staticfiles
. It provides the same behavior asdjango.contrib.staticfiles
but with extra security guarantees (more info below in Security Notes).
-
Changed the syntax for
{% slot %}
tags. From now on, we separate defining a slot ({% slot %}
) from filling a slot with content ({% fill %}
). This means you will likely need to change a lot of slot tags to fill.We understand this is annoying, but it's the only way we can get support for nested slots that fill in other slots, which is a very nice feature to have access to. Hoping that this will feel worth it!
-
All files inside components subdirectores are autoimported to simplify setup.
An existing project might start to get
AlreadyRegistered
errors because of this. To solve this, either remove your custom loading of components, or set\"autodiscover\": False
insettings.COMPONENTS
.
-
Renamed
Component.context
andComponent.template
toget_context_data
andget_template_name
. The old methods still work, but emit a deprecation warning.This change was done to sync naming with Django's class based views, and make using django-components more familiar to Django users.
Component.context
andComponent.template
will be removed when version 1.0 is released.
You can publish and share your components for others to use. Below you will find the steps to do so.
For live examples, see the Community examples.
"},{"location":"concepts/advanced/authoring_component_libraries/#writing-component-libraries","title":"Writing component libraries","text":"-
Create a Django project with a similar structure:
project/\n |-- myapp/\n |-- __init__.py\n |-- apps.py\n |-- templates/\n |-- table/\n |-- table.py\n |-- table.js\n |-- table.css\n |-- table.html\n |-- menu.py <--- single-file component\n |-- templatetags/\n |-- __init__.py\n |-- mytags.py\n
-
Create custom
Library
andComponentRegistry
instances inmytags.py
This will be the entrypoint for using the components inside Django templates.
Remember that Django requires the
Library
instance to be accessible under theregister
variable (See Django docs):from django.template import Library\nfrom django_components import ComponentRegistry, RegistrySettings\n\nregister = library = django.template.Library()\ncomp_registry = ComponentRegistry(\n library=library,\n settings=RegistrySettings(\n context_behavior=\"isolated\",\n tag_formatter=\"django_components.component_formatter\",\n ),\n)\n
As you can see above, this is also the place where we configure how our components should behave, using the
settings
argument. If omitted, default settings are used.For library authors, we recommend setting
context_behavior
to\"isolated\"
, so that the state cannot leak into the components, and so the components' behavior is configured solely through the inputs. This means that the components will be more predictable and easier to debug.Next, you can decide how will others use your components by setting the
tag_formatter
options.If omitted or set to
\"django_components.component_formatter\"
, your components will be used like this:{% component \"table\" items=items headers=headers %}\n{% endcomponent %}\n
Or you can use
\"django_components.component_shorthand_formatter\"
to use components like so:{% table items=items headers=headers %}\n{% endtable %}\n
Or you can define a custom TagFormatter.
Either way, these settings will be scoped only to your components. So, in the user code, there may be components side-by-side that use different formatters:
{% load mytags %}\n\n{# Component from your library \"mytags\", using the \"shorthand\" formatter #}\n{% table items=items headers=header %}\n{% endtable %}\n\n{# User-created components using the default settings #}\n{% component \"my_comp\" title=\"Abc...\" %}\n{% endcomponent %}\n
-
Write your components and register them with your instance of
ComponentRegistry
There's one difference when you are writing components that are to be shared, and that's that the components must be explicitly registered with your instance of
ComponentRegistry
from the previous step.For better user experience, you can also define the types for the args, kwargs, slots and data.
It's also a good idea to have a common prefix for your components, so they can be easily distinguished from users' components. In the example below, we use the prefix
my_
/My
.from typing import Dict, NotRequired, Optional, Tuple, TypedDict\n\nfrom django_components import Component, SlotFunc, register, types\n\nfrom myapp.templatetags.mytags import comp_registry\n\n# Define the types\nclass EmptyDict(TypedDict):\n pass\n\ntype MyMenuArgs = Tuple[int, str]\n\nclass MyMenuSlots(TypedDict):\n default: NotRequired[Optional[SlotFunc[EmptyDict]]]\n\nclass MyMenuProps(TypedDict):\n vertical: NotRequired[bool]\n klass: NotRequired[str]\n style: NotRequired[str]\n\n# Define the component\n# NOTE: Don't forget to set the `registry`!\n@register(\"my_menu\", registry=comp_registry)\nclass MyMenu(Component[MyMenuArgs, MyMenuProps, MyMenuSlots, Any, Any, Any]):\n def get_context_data(\n self,\n *args,\n attrs: Optional[Dict] = None,\n ):\n return {\n \"attrs\": attrs,\n }\n\n template: types.django_html = \"\"\"\n {# Load django_components template tags #}\n {% load component_tags %}\n\n <div {% html_attrs attrs class=\"my-menu\" %}>\n <div class=\"my-menu__content\">\n {% slot \"default\" default / %}\n </div>\n </div>\n \"\"\"\n
-
Import the components in
apps.py
Normally, users rely on autodiscovery and
COMPONENTS.dirs
to load the component files.Since you, as the library author, are not in control of the file system, it is recommended to load the components manually.
We recommend doing this in the
AppConfig.ready()
hook of yourapps.py
:from django.apps import AppConfig\n\nclass MyAppConfig(AppConfig):\n default_auto_field = \"django.db.models.BigAutoField\"\n name = \"myapp\"\n\n # This is the code that gets run when user adds myapp\n # to Django's INSTALLED_APPS\n def ready(self) -> None:\n # Import the components that you want to make available\n # inside the templates.\n from myapp.templates import (\n menu,\n table,\n )\n
Note that you can also include any other startup logic within
AppConfig.ready()
.
And that's it! The next step is to publish it.
"},{"location":"concepts/advanced/authoring_component_libraries/#publishing-component-libraries","title":"Publishing component libraries","text":"Once you are ready to share your library, you need to build a distribution and then publish it to PyPI.
django_components uses the
build
utility to build a distribution:python -m build --sdist --wheel --outdir dist/ .\n
And to publish to PyPI, you can use
twine
(See Python user guide)twine upload --repository pypi dist/* -u __token__ -p <PyPI_TOKEN>\n
Notes on publishing:
- If you use components where the HTML / CSS / JS files are separate, you may need to define
MANIFEST.in
to include those files with the distribution (see user guide).
After the package has been published, all that remains is to install it in other django projects:
-
Install the package:
pip install myapp django_components\n
-
Add the package to
INSTALLED_APPS
INSTALLED_APPS = [\n ...\n \"django_components\",\n \"myapp\",\n]\n
-
Optionally add the template tags to the
builtins
, so you don't have to call{% load mytags %}
in every template:TEMPLATES = [\n {\n ...,\n 'OPTIONS': {\n 'builtins': [\n 'myapp.templatetags.mytags',\n ]\n },\n },\n]\n
-
And, at last, you can use the components in your own project!
{% my_menu title=\"Abc...\" %}\n Hello World!\n{% endmy_menu %}\n
In previous examples you could repeatedly see us using
@register()
to \"register\" the components. In this section we dive deeper into what it actually means and how you can manage (add or remove) components.As a reminder, we may have a component like this:
from django_components import Component, register\n\n@register(\"calendar\")\nclass Calendar(Component):\n template_file = \"template.html\"\n\n # This component takes one parameter, a date string to show in the template\n def get_context_data(self, date):\n return {\n \"date\": date,\n }\n
which we then render in the template as:
{% component \"calendar\" date=\"1970-01-01\" %}\n{% endcomponent %}\n
As you can see,
"},{"location":"concepts/advanced/component_registry/#what-is-componentregistry","title":"What is ComponentRegistry","text":"@register
links up the component class with the{% component %}
template tag. So when the template tag comes across a component called\"calendar\"
, it can look up it's class and instantiate it.The
@register
decorator is a shortcut for working with theComponentRegistry
.ComponentRegistry
manages which components can be used in the template tags.Each
ComponentRegistry
instance is associated with an instance of Django'sLibrary
. And Libraries are inserted into Django template using the{% load %}
tags.The
@register
decorator accepts an optional kwargregistry
, which specifies, theComponentRegistry
to register components into. If omitted, the defaultComponentRegistry
instance defined in django_components is used.my_registry = ComponentRegistry()\n\n@register(registry=my_registry)\nclass MyComponent(Component):\n ...\n
The default
ComponentRegistry
is associated with theLibrary
that you load when you call{% load component_tags %}
inside your template, or when you adddjango_components.templatetags.component_tags
to the template builtins.So when you register or unregister a component to/from a component registry, then behind the scenes the registry automatically adds/removes the component's template tags to/from the Library, so you can call the component from within the templates such as
"},{"location":"concepts/advanced/component_registry/#working-with-componentregistry","title":"Working with ComponentRegistry","text":"{% component \"my_comp\" %}
.The default
ComponentRegistry
instance can be imported as:from django_components import registry\n
You can use the registry to manually add/remove/get components:
"},{"location":"concepts/advanced/component_registry/#registering-components-to-custom-componentregistry","title":"Registering components to custom ComponentRegistry","text":"from django_components import registry\n\n# Register components\nregistry.register(\"button\", ButtonComponent)\nregistry.register(\"card\", CardComponent)\n\n# Get all or single\nregistry.all() # {\"button\": ButtonComponent, \"card\": CardComponent}\nregistry.get(\"card\") # CardComponent\n\n# Unregister single component\nregistry.unregister(\"card\")\n\n# Unregister all components\nregistry.clear()\n
If you are writing a component library to be shared with others, you may want to manage your own instance of
ComponentRegistry
and register components onto a differentLibrary
instance than the default one.The
Library
instance can be set at instantiation ofComponentRegistry
. If omitted, then the default Library instance from django_components is used.from django.template import Library\nfrom django_components import ComponentRegistry\n\nmy_library = Library(...)\nmy_registry = ComponentRegistry(library=my_library)\n
When you have defined your own
ComponentRegistry
, you can either register the components withmy_registry.register()
, or pass the registry to the@component.register()
decorator via theregistry
kwarg:from path.to.my.registry import my_registry\n\n@register(\"my_component\", registry=my_registry)\nclass MyComponent(Component):\n ...\n
NOTE: The Library instance can be accessed under
"},{"location":"concepts/advanced/component_registry/#componentregistry-settings","title":"ComponentRegistry settings","text":"library
attribute ofComponentRegistry
.When you are creating an instance of
ComponentRegistry
, you can define the components' behavior within the template.The registry accepts these settings:
context_behavior
tag_formatter
from django.template import Library\nfrom django_components import ComponentRegistry, RegistrySettings\n\nregister = library = django.template.Library()\ncomp_registry = ComponentRegistry(\n library=library,\n settings=RegistrySettings(\n context_behavior=\"isolated\",\n tag_formatter=\"django_components.component_formatter\",\n ),\n)\n
These settings are the same as the ones you can set for django_components.
In fact, when you set
COMPONENT.tag_formatter
orCOMPONENT.context_behavior
, these are forwarded to the defaultComponentRegistry
.This makes it possible to have multiple registries with different settings in one projects, and makes sharing of component libraries possible.
"},{"location":"concepts/advanced/hooks/","title":"Lifecycle hooks","text":"New in version 0.96
Component hooks are functions that allow you to intercept the rendering process at specific positions.
"},{"location":"concepts/advanced/hooks/#available-hooks","title":"Available hooks","text":"on_render_before
def on_render_before(\n self: Component,\n context: Context,\n template: Template\n) -> None:\n
Hook that runs just before the component's template is rendered.
You can use this hook to access or modify the context or the template:
def on_render_before(self, context, template) -> None:\n # Insert value into the Context\n context[\"from_on_before\"] = \":)\"\n\n # Append text into the Template\n template.nodelist.append(TextNode(\"FROM_ON_BEFORE\"))\n
on_render_after
def on_render_after(\n self: Component,\n context: Context,\n template: Template,\n content: str\n) -> None | str | SafeString:\n
Hook that runs just after the component's template was rendered. It receives the rendered output as the last argument.
You can use this hook to access the context or the template, but modifying them won't have any effect.
To override the content that gets rendered, you can return a string or SafeString from this hook:
"},{"location":"concepts/advanced/hooks/#component-hooks-example","title":"Component hooks example","text":"def on_render_after(self, context, template, content):\n # Prepend text to the rendered content\n return \"Chocolate cookie recipe: \" + content\n
You can use hooks together with provide / inject to create components that accept a list of items via a slot.
In the example below, each
tab_item
component will be rendered on a separate tab page, but they are all defined in the default slot of thetabs
component.See here for how it was done
"},{"location":"concepts/advanced/html_tragments/","title":"HTML fragments","text":"{% component \"tabs\" %}\n {% component \"tab_item\" header=\"Tab 1\" %}\n <p>\n hello from tab 1\n </p>\n {% component \"button\" %}\n Click me!\n {% endcomponent %}\n {% endcomponent %}\n\n {% component \"tab_item\" header=\"Tab 2\" %}\n Hello this is tab 2\n {% endcomponent %}\n{% endcomponent %}\n
Django-components provides a seamless integration with HTML fragments (HTML over the wire), whether you're using HTMX, AlpineJS, or vanilla JavaScript.
When you define a component that has extra JS or CSS, and you use django-components to render the fragment, django-components will:
- Automatically load the associated JS and CSS
- Ensure that JS is loaded and executed only once even if the fragment is inserted multiple times
Info
What are HTML fragments and \"HTML over the wire\"?
It is one of the methods for updating the state in the browser UI upon user interaction.
How it works is that:
- User makes an action - clicks a button or submits a form
- The action causes a request to be made from the client to the server.
- Server processes the request (e.g. form submission), and responds with HTML of some part of the UI (e.g. a new entry in a table).
- A library like HTMX, AlpineJS, or custom function inserts the new HTML into the correct place.
Components support two modes of rendering - As a \"document\" or as a \"fragment\".
What's the difference?
"},{"location":"concepts/advanced/html_tragments/#document-mode","title":"Document mode","text":"Document mode assumes that the rendered components will be embedded into the HTML of the initial page load. This means that:
- The JS and CSS is embedded into the HTML as
<script>
and<style>
tags (see JS and CSS output locations) - Django-components injects a JS script for managing JS and CSS assets
A component is rendered as a \"document\" when:
- It is embedded inside a template as
{% component %}
- It is rendered with
Component.render()
orComponent.render_to_response()
with thetype
kwarg set to\"document\"
(default)
Example:
"},{"location":"concepts/advanced/html_tragments/#fragment-mode","title":"Fragment mode","text":"MyTable.render(\n kwargs={...},\n)\n\n# or\n\nMyTable.render(\n kwargs={...},\n type=\"document\",\n)\n
Fragment mode assumes that the main HTML has already been rendered and loaded on the page. The component renders HTML that will be inserted into the page as a fragment, at a LATER time:
- JS and CSS is not directly embedded to avoid duplicately executing the same JS scripts. So template tags like
{% component_js_dependencies %}
inside of fragments are ignored. - Instead, django-components appends the fragment's content with a JSON
<script>
to trigger a call to its asset manager JS script, which will load the JS and CSS smartly. - The asset manager JS script is assumed to be already loaded on the page.
A component is rendered as \"fragment\" when:
- It is rendered with
Component.render()
orComponent.render_to_response()
with thetype
kwarg set to\"fragment\"
Example:
"},{"location":"concepts/advanced/html_tragments/#live-examples","title":"Live examples","text":"MyTable.render(\n kwargs={...},\n type=\"fragment\",\n)\n
For live interactive examples, start our demo project (
sampleproject
).Then navigate to these URLs:
/fragment/base/alpine
/fragment/base/htmx
/fragment/base/js
"},{"location":"concepts/advanced/html_tragments/#2-define-fragment-html","title":"2. Define fragment HTML","text":"[root]/components/demo.pyfrom django_components import Component, types\n\n# HTML into which a fragment will be loaded using HTMX\nclass MyPage(Component):\n def get(self, request):\n return self.render_to_response()\n\n template = \"\"\"\n {% load component_tags %}\n <!DOCTYPE html>\n <html>\n <head>\n {% component_css_dependencies %}\n <script src=\"https://unpkg.com/htmx.org@1.9.12\"></script>\n </head>\n <body>\n <div id=\"target\">OLD</div>\n\n <button\n hx-get=\"/mypage/frag\"\n hx-swap=\"outerHTML\"\n hx-target=\"#target\"\n >\n Click me!\n </button>\n\n {% component_js_dependencies %}\n </body>\n </html>\n \"\"\"\n
"},{"location":"concepts/advanced/html_tragments/#3-create-view-and-urls","title":"3. Create view and URLs","text":"[app]/urls.pyclass Frag(Component):\n def get(self, request):\n return self.render_to_response(\n # IMPORTANT: Don't forget `type=\"fragment\"`\n type=\"fragment\",\n )\n\n template = \"\"\"\n <div class=\"frag\">\n 123\n <span id=\"frag-text\"></span>\n </div>\n \"\"\"\n\n js = \"\"\"\n document.querySelector('#frag-text').textContent = 'xxx';\n \"\"\"\n\n css = \"\"\"\n .frag {\n background: blue;\n }\n \"\"\"\n
"},{"location":"concepts/advanced/html_tragments/#example-alpinejs","title":"Example - AlpineJS","text":""},{"location":"concepts/advanced/html_tragments/#1-define-document-html_1","title":"1. Define document HTML","text":"[root]/components/demo.pyfrom django.urls import path\n\nfrom components.demo import MyPage, Frag\n\nurlpatterns = [\n path(\"mypage/\", MyPage.as_view())\n path(\"mypage/frag\", Frag.as_view()),\n]\n
"},{"location":"concepts/advanced/html_tragments/#2-define-fragment-html_1","title":"2. Define fragment HTML","text":"[root]/components/demo.pyfrom django_components import Component, types\n\n# HTML into which a fragment will be loaded using AlpineJS\nclass MyPage(Component):\n def get(self, request):\n return self.render_to_response()\n\n template = \"\"\"\n {% load component_tags %}\n <!DOCTYPE html>\n <html>\n <head>\n {% component_css_dependencies %}\n <script defer src=\"https://unpkg.com/alpinejs\"></script>\n </head>\n <body x-data=\"{\n htmlVar: 'OLD',\n loadFragment: function () {\n const url = '/mypage/frag';\n fetch(url)\n .then(response => response.text())\n .then(html => {\n this.htmlVar = html;\n });\n }\n }\">\n <div id=\"target\" x-html=\"htmlVar\">OLD</div>\n\n <button @click=\"loadFragment\">\n Click me!\n </button>\n\n {% component_js_dependencies %}\n </body>\n </html>\n \"\"\"\n
"},{"location":"concepts/advanced/html_tragments/#3-create-view-and-urls_1","title":"3. Create view and URLs","text":"[app]/urls.pyclass Frag(Component):\n def get(self, request):\n # IMPORTANT: Don't forget `type=\"fragment\"`\n return self.render_to_response(\n type=\"fragment\",\n )\n\n # NOTE: We wrap the actual fragment in a template tag with x-if=\"false\" to prevent it\n # from being rendered until we have registered the component with AlpineJS.\n template = \"\"\"\n <template x-if=\"false\" data-name=\"frag\">\n <div class=\"frag\">\n 123\n <span x-data=\"frag\" x-text=\"fragVal\">\n </span>\n </div>\n </template>\n \"\"\"\n\n js = \"\"\"\n Alpine.data('frag', () => ({\n fragVal: 'xxx',\n }));\n\n // Now that the component has been defined in AlpineJS, we can \"activate\"\n // all instances where we use the `x-data=\"frag\"` directive.\n document.querySelectorAll('[data-name=\"frag\"]').forEach((el) => {\n el.setAttribute('x-if', 'true');\n });\n \"\"\"\n\n css = \"\"\"\n .frag {\n background: blue;\n }\n \"\"\"\n
"},{"location":"concepts/advanced/html_tragments/#example-vanilla-js","title":"Example - Vanilla JS","text":""},{"location":"concepts/advanced/html_tragments/#1-define-document-html_2","title":"1. Define document HTML","text":"[root]/components/demo.pyfrom django.urls import path\n\nfrom components.demo import MyPage, Frag\n\nurlpatterns = [\n path(\"mypage/\", MyPage.as_view())\n path(\"mypage/frag\", Frag.as_view()),\n]\n
"},{"location":"concepts/advanced/html_tragments/#2-define-fragment-html_2","title":"2. Define fragment HTML","text":"[root]/components/demo.pyfrom django_components import Component, types\n\n# HTML into which a fragment will be loaded using JS\nclass MyPage(Component):\n def get(self, request):\n return self.render_to_response()\n\n template = \"\"\"\n {% load component_tags %}\n <!DOCTYPE html>\n <html>\n <head>\n {% component_css_dependencies %}\n </head>\n <body>\n <div id=\"target\">OLD</div>\n\n <button>\n Click me!\n </button>\n <script>\n const url = `/mypage/frag`;\n document.querySelector('#loader').addEventListener('click', function () {\n fetch(url)\n .then(response => response.text())\n .then(html => {\n document.querySelector('#target').outerHTML = html;\n });\n });\n </script>\n\n {% component_js_dependencies %}\n </body>\n </html>\n \"\"\"\n
"},{"location":"concepts/advanced/html_tragments/#3-create-view-and-urls_2","title":"3. Create view and URLs","text":"[app]/urls.pyclass Frag(Component):\n def get(self, request):\n return self.render_to_response(\n # IMPORTANT: Don't forget `type=\"fragment\"`\n type=\"fragment\",\n )\n\n template = \"\"\"\n <div class=\"frag\">\n 123\n <span id=\"frag-text\"></span>\n </div>\n \"\"\"\n\n js = \"\"\"\n document.querySelector('#frag-text').textContent = 'xxx';\n \"\"\"\n\n css = \"\"\"\n .frag {\n background: blue;\n }\n \"\"\"\n
"},{"location":"concepts/advanced/provide_inject/","title":"Prop drilling and provide / inject","text":"from django.urls import path\n\nfrom components.demo import MyPage, Frag\n\nurlpatterns = [\n path(\"mypage/\", MyPage.as_view())\n path(\"mypage/frag\", Frag.as_view()),\n]\n
New in version 0.80:
Django components supports the provide / inject or ContextProvider pattern with the combination of:
{% provide %}
taginject()
method of theComponent
class
Prop drilling refers to a scenario in UI development where you need to pass data through many layers of a component tree to reach the nested components that actually need the data.
Normally, you'd use props to send data from a parent component to its children. However, this straightforward method becomes cumbersome and inefficient if the data has to travel through many levels or if several components scattered at different depths all need the same piece of information.
This results in a situation where the intermediate components, which don't need the data for their own functioning, end up having to manage and pass along these props. This clutters the component tree and makes the code verbose and harder to manage.
A neat solution to avoid prop drilling is using the \"provide and inject\" technique.
With provide / inject, a parent component acts like a data hub for all its descendants. This setup allows any component, no matter how deeply nested it is, to access the required data directly from this centralized provider without having to messily pass props down the chain. This approach significantly cleans up the code and makes it easier to maintain.
This feature is inspired by Vue's Provide / Inject and React's Context / useContext.
"},{"location":"concepts/advanced/provide_inject/#how-to-use-provide-inject","title":"How to use provide / inject","text":"As the name suggest, using provide / inject consists of 2 steps
- Providing data
- Injecting provided data
For examples of advanced uses of provide / inject, see this discussion.
"},{"location":"concepts/advanced/provide_inject/#using-provide-tag","title":"Using{% provide %}
tag","text":"First we use the
{% provide %}
tag to define the data we want to \"provide\" (make available).{% provide \"my_data\" key=\"hi\" another=123 %}\n {% component \"child\" / %} <--- Can access \"my_data\"\n{% endprovide %}\n\n{% component \"child\" / %} <--- Cannot access \"my_data\"\n
Notice that the
provide
tag REQUIRES a name as a first argument. This is the key by which we can then access the data passed to this tag.provide
tag name must resolve to a valid identifier (AKA a valid Python variable name).Once you've set the name, you define the data you want to \"provide\" by passing it as keyword arguments. This is similar to how you pass data to the
{% with %}
tag.NOTE: Kwargs passed to
{% provide %}
are NOT added to the context. In the example below, the{{ key }}
won't render anything:{% provide \"my_data\" key=\"hi\" another=123 %}\n {{ key }}\n{% endprovide %}\n
Similarly to slots and fills, also provide's name argument can be set dynamically via a variable, a template expression, or a spread operator:
"},{"location":"concepts/advanced/provide_inject/#using-inject-method","title":"Using{% provide name=name ... %}\n ...\n{% provide %}\n</table>\n
inject()
method","text":"To \"inject\" (access) the data defined on the
provide
tag, you can use theinject()
method inside ofget_context_data()
.For a component to be able to \"inject\" some data, the component (
{% component %}
tag) must be nested inside the{% provide %}
tag.In the example from previous section, we've defined two kwargs:
key=\"hi\" another=123
. That means that if we now inject\"my_data\"
, we get an object with 2 attributes -key
andanother
.class ChildComponent(Component):\n def get_context_data(self):\n my_data = self.inject(\"my_data\")\n print(my_data.key) # hi\n print(my_data.another) # 123\n return {}\n
First argument to
inject
is the key (or name) of the provided data. This must match the string that you used in theprovide
tag. If no provider with given key is found,inject
raises aKeyError
.To avoid the error, you can pass a second argument to
inject
to which will act as a default value, similar todict.get(key, default)
:class ChildComponent(Component):\n def get_context_data(self):\n my_data = self.inject(\"invalid_key\", DEFAULT_DATA)\n assert my_data == DEFAUKT_DATA\n return {}\n
The instance returned from
inject()
is a subclass ofNamedTuple
, so the instance is immutable. This ensures that the data returned frominject
will always have all the keys that were passed to theprovide
tag.NOTE:
"},{"location":"concepts/advanced/provide_inject/#full-example","title":"Full example","text":"inject()
works strictly only inget_context_data
. If you try to call it from elsewhere, it will raise an error.@register(\"child\")\nclass ChildComponent(Component):\n template = \"\"\"\n <div> {{ my_data.key }} </div>\n <div> {{ my_data.another }} </div>\n \"\"\"\n\n def get_context_data(self):\n my_data = self.inject(\"my_data\", \"default\")\n return {\"my_data\": my_data}\n\ntemplate_str = \"\"\"\n {% load component_tags %}\n {% provide \"my_data\" key=\"hi\" another=123 %}\n {% component \"child\" / %}\n {% endprovide %}\n\"\"\"\n
renders:
"},{"location":"concepts/advanced/rendering_js_css/","title":"Rendering JS / CSS","text":""},{"location":"concepts/advanced/rendering_js_css/#js-and-css-output-locations","title":"JS and CSS output locations","text":"<div>hi</div>\n<div>123</div>\n
If:
- Your components use JS and CSS via any of:
Component.css
Component.js
Component.Media.css
Component.Media.js
- And you use the
ComponentDependencyMiddleware
middleware
Then, by default, the components' JS and CSS will be automatically inserted into the HTML:
- CSS styles will be inserted at the end of the
<head>
- JS scripts will be inserted at the end of the
<body>
If you want to place the dependencies elsewhere in the HTML, you can override the locations by inserting following Django template tags:
{% component_js_dependencies %}
- Set new location(s) for JS scripts{% component_css_dependencies %}
- Set new location(s) for CSS styles
So if you have a component with JS and CSS:
from django_components import Component, types\n\nclass MyButton(Component):\n template: types.django_html = \"\"\"\n <button class=\"my-button\">\n Click me!\n </button>\n \"\"\"\n js: types.js = \"\"\"\n for (const btnEl of document.querySelectorAll(\".my-button\")) {\n btnEl.addEventListener(\"click\", () => {\n console.log(\"BUTTON CLICKED!\");\n });\n }\n \"\"\"\n css: types.css \"\"\"\n .my-button {\n background: green;\n }\n \"\"\"\n\n class Media:\n js = [\"/extra/script.js\"]\n css = [\"/extra/style.css\"]\n
Then the JS from
MyButton.js
andMyButton.Media.js
will be rendered at the default place, or in{% component_js_dependencies %}
.And the CSS from
MyButton.css
andMyButton.Media.css
will be rendered at the default place, or in{% component_css_dependencies %}
.And if you don't specify
{% component_dependencies %}
tags, it is the equivalent of:
"},{"location":"concepts/advanced/rendering_js_css/#setting-up-the-middleware","title":"Setting up the middleware","text":"<!doctype html>\n<html>\n <head>\n <title>MyPage</title>\n ...\n {% component_css_dependencies %}\n </head>\n <body>\n <main>\n ...\n </main>\n {% component_js_dependencies %}\n </body>\n</html>\n
ComponentDependencyMiddleware
is a Django middleware designed to manage and inject CSS / JS dependencies of rendered components dynamically. It ensures that only the necessary stylesheets and scripts are loaded in your HTML responses, based on the components used in your Django templates.To set it up, add the middleware to your
MIDDLEWARE
insettings.py
:
"},{"location":"concepts/advanced/rendering_js_css/#render_dependencies-and-rendering-js-css-without-the-middleware","title":"MIDDLEWARE = [\n # ... other middleware classes ...\n 'django_components.middleware.ComponentDependencyMiddleware'\n # ... other middleware classes ...\n]\n
render_dependencies
and rendering JS / CSS without the middleware","text":"For most scenarios, using the
ComponentDependencyMiddleware
middleware will be just fine.However, this section is for you if you want to:
- Render HTML that will NOT be sent as a server response
- Insert pre-rendered HTML into another component
- Render HTML fragments (partials)
Every time there is an HTML string that has parts which were rendered using components, and any of those components has JS / CSS, then this HTML string MUST be processed with
render_dependencies()
.It is actually
"},{"location":"concepts/advanced/rendering_js_css/#render-js-css-without-the-middleware","title":"Render JS / CSS without the middleware","text":"render_dependencies()
that finds all used components in the HTML string, and inserts the component's JS and CSS into{% component_dependencies %}
tags, or at the default locations.The truth is that the
ComponentDependencyMiddleware
middleware just callsrender_dependencies()
, passing in the HTML content. So if you render a template that contained{% component %}
tags, you MUST pass the result throughrender_dependencies()
. And the middleware is just one of the options.Here is how you can achieve the same, without the middleware, using
render_dependencies()
:from django.template.base import Template\nfrom django.template.context import Context\nfrom django_component import render_dependencies\n\ntemplate = Template(\"\"\"\n {% load component_tags %}\n <!doctype html>\n <html>\n <head>\n <title>MyPage</title>\n </head>\n <body>\n <main>\n {% component \"my_button\" %}\n Click me!\n {% endcomponent %}\n </main>\n </body>\n </html>\n\"\"\")\n\nrendered = template.render(Context())\nrendered = render_dependencies(rendered)\n
Same applies if you render a template using Django's
django.shortcuts.render
:from django.shortcuts import render\n\ndef my_view(request):\n rendered = render(request, \"pages/home.html\")\n rendered = render_dependencies(rendered)\n return rendered\n
Alternatively, when you render HTML with
Component.render()
orComponent.render_to_response()
, these, by default, callrender_dependencies()
for you, so you don't have to:
"},{"location":"concepts/advanced/rendering_js_css/#inserting-pre-rendered-html-into-another-component","title":"Inserting pre-rendered HTML into another component","text":"from django_components import Component\n\nclass MyButton(Component):\n ...\n\n# No need to call `render_dependencies()`\nrendered = MyButton.render()\n
In previous section we've shown that
render_dependencies()
does NOT need to be called when you render a component viaComponent.render()
.API of django_components makes it possible to compose components in a \"React-like\" way, where we pre-render a piece of HTML and then insert it into a larger structure.
To do this, you must add
render_dependencies=False
to the nested components:card_actions = CardActions.render(\n kwargs={\"editable\": editable},\n render_dependencies=False,\n)\n\ncard = Card.render(\n slots={\"actions\": card_actions},\n render_dependencies=False,\n)\n\npage = MyPage.render(\n slots={\"card\": card},\n)\n
Why is
render_dependencies=False
required?This is a technical limitation of the current implementation.
As mentioned earlier, each time we call
Component.render()
, we also callrender_dependencies()
.However, there is a problem here - When we call
render_dependencies()
insideCardActions.render()
, we extract and REMOVE the info on components' JS and CSS from the HTML. But the template ofCardActions
contains no{% component_depedencies %}
tags, and nor<head>
nor<body>
HTML tags. So the component's JS and CSS will NOT be inserted, and will be lost.To work around this, you must set
"},{"location":"concepts/advanced/rendering_js_css/#summary","title":"Summary","text":"render_dependencies=False
when rendering pieces of HTML withComponent.render()
and inserting them into larger structures.- Every time you render HTML that contained components, you have to call
render_dependencies()
on the rendered output. - There are several ways to call
render_dependencies()
:- Using the
ComponentDependencyMiddleware
middleware - Rendering the HTML by calling
Component.render()
withrender_dependencies=True
(default) - Rendering the HTML by calling
Component.render_to_response()
(always renders dependencies) - Directly passing rendered HTML to
render_dependencies()
- Using the
- If you pre-render one component to pass it into another, the pre-rendered component must be rendered with
render_dependencies=False
.
New in version 0.89
By default, components are rendered using the pair of
{% component %}
/{% endcomponent %}
template tags:{% component \"button\" href=\"...\" disabled %}\nClick me!\n{% endcomponent %}\n\n{# or #}\n\n{% component \"button\" href=\"...\" disabled / %}\n
You can change this behaviour in the settings under the
COMPONENTS.tag_formatter
.For example, if you set the tag formatter to
django_components.component_shorthand_formatter
then the components' names will be used as the template tags:
"},{"location":"concepts/advanced/tag_formatter/#available-tagformatters","title":"Available TagFormatters","text":"{% button href=\"...\" disabled %}\n Click me!\n{% endbutton %}\n\n{# or #}\n\n{% button href=\"...\" disabled / %}\n
django_components provides following predefined TagFormatters:
ComponentFormatter
(django_components.component_formatter
)
Default
Uses the
component
andendcomponent
tags, and the component name is gives as the first positional argument.Example as block:
{% component \"button\" href=\"...\" %}\n {% fill \"content\" %}\n ...\n {% endfill %}\n{% endcomponent %}\n
Example as inlined tag:
{% component \"button\" href=\"...\" / %}\n
ShorthandComponentFormatter
(django_components.component_shorthand_formatter
)
Uses the component name as start tag, and
end<component_name>
as an end tag.Example as block:
{% button href=\"...\" %}\n Click me!\n{% endbutton %}\n
Example as inlined tag:
"},{"location":"concepts/advanced/tag_formatter/#writing-your-own-tagformatter","title":"Writing your own TagFormatter","text":""},{"location":"concepts/advanced/tag_formatter/#background","title":"Background","text":"{% button href=\"...\" / %}\n
First, let's discuss how TagFormatters work, and how components are rendered in django_components.
When you render a component with
{% component %}
(or your own tag), the following happens:component
must be registered as a Django's template tag- Django triggers django_components's tag handler for tag
component
. - The tag handler passes the tag contents for pre-processing to
TagFormatter.parse()
.
So if you render this:
{% component \"button\" href=\"...\" disabled %}\n{% endcomponent %}\n
Then
TagFormatter.parse()
will receive a following input:[\"component\", '\"button\"', 'href=\"...\"', 'disabled']\n
TagFormatter
extracts the component name and the remaining input.
So, given the above,
TagFormatter.parse()
returns the following:TagResult(\n component_name=\"button\",\n tokens=['href=\"...\"', 'disabled']\n)\n
- The tag handler resumes, using the tokens returned from
TagFormatter
.
So, continuing the example, at this point the tag handler practically behaves as if you rendered:
{% component href=\"...\" disabled %}\n
- Tag handler looks up the component
button
, and passes the args, kwargs, and slots to it.
TagFormatter
handles following parts of the process above:-
Generates start/end tags, given a component. This is what you then call from within your template as
{% component %}
. -
When you
{% component %}
, tag formatter pre-processes the tag contents, so it can link back the custom template tag to the right component.
To do so, subclass from
TagFormatterABC
and implement following method:start_tag
end_tag
parse
For example, this is the implementation of
ShorthandComponentFormatter
class ShorthandComponentFormatter(TagFormatterABC):\n # Given a component name, generate the start template tag\n def start_tag(self, name: str) -> str:\n return name # e.g. 'button'\n\n # Given a component name, generate the start template tag\n def end_tag(self, name: str) -> str:\n return f\"end{name}\" # e.g. 'endbutton'\n\n # Given a tag, e.g.\n # `{% button href=\"...\" disabled %}`\n #\n # The parser receives:\n # `['button', 'href=\"...\"', 'disabled']`\n def parse(self, tokens: List[str]) -> TagResult:\n tokens = [*tokens]\n name = tokens.pop(0)\n return TagResult(\n name, # e.g. 'button'\n tokens # e.g. ['href=\"...\"', 'disabled']\n )\n
That's it! And once your
"},{"location":"concepts/advanced/template_tags/","title":"Custom template tags","text":"TagFormatter
is ready, don't forget to update the settings!Template tags introduced by django-components, such as
{% component %}
and{% slot %}
, offer additional features over the default Django template tags:- Self-closing tags
{% mytag / %}
- Allowing the use of
:
,-
(and more) in keys - Spread operator
...
- Using template tags as inputs to other template tags
- Flat definition of dictionaries
attr:key=val
- Function-like input validation
You too can easily create custom template tags that use the above features.
"},{"location":"concepts/advanced/template_tags/#defining-template-tags-with-template_tag","title":"Defining template tags with@template_tag
","text":"The simplest way to create a custom template tag is using the
template_tag
decorator. This decorator allows you to define a template tag by just writing a function that returns the rendered content.from django.template import Context, Library\nfrom django_components import BaseNode, template_tag\n\nlibrary = Library()\n\n@template_tag(\n library,\n tag=\"mytag\",\n end_tag=\"endmytag\",\n allowed_flags=[\"required\"]\n)\ndef mytag(node: BaseNode, context: Context, name: str, **kwargs) -> str:\n return f\"Hello, {name}!\"\n
This will allow you to use the tag in your templates like this:
"},{"location":"concepts/advanced/template_tags/#parameters","title":"Parameters","text":"{% mytag name=\"John\" %}\n{% endmytag %}\n\n{# or with self-closing syntax #}\n{% mytag name=\"John\" / %}\n\n{# or with flags #}\n{% mytag name=\"John\" required %}\n{% endmytag %}\n
The
@template_tag
decorator accepts the following parameters:library
: The Django template library to register the tag withtag
: The name of the template tag (e.g.\"mytag\"
for{% mytag %}
)end_tag
: Optional. The name of the end tag (e.g.\"endmytag\"
for{% endmytag %}
)allowed_flags
: Optional. List of flags that can be used with the tag (e.g.[\"required\"]
for{% mytag required %}
)
The function decorated with
@template_tag
must accept at least two arguments:node
: The node instance (we'll explain this in detail in the next section)context
: The Django template context
Any additional parameters in your function's signature define what inputs your template tag accepts. For example:
@template_tag(library, tag=\"greet\")\ndef greet(\n node: BaseNode,\n context: Context,\n name: str, # required positional argument\n count: int = 1, # optional positional argument\n *, # keyword-only arguments marker\n msg: str, # required keyword argument\n mode: str = \"default\", # optional keyword argument\n) -> str:\n return f\"{msg}, {name}!\" * count\n
This allows the tag to be used like:
{# All parameters #}\n{% greet \"John\" count=2 msg=\"Hello\" mode=\"custom\" %}\n\n{# Only required parameters #}\n{% greet \"John\" msg=\"Hello\" %}\n\n{# Missing required parameter - will raise error #}\n{% greet \"John\" %} {# Error: missing 'msg' #}\n
When you pass input to a template tag, it behaves the same way as if you passed the input to a function:
- If required parameters are missing, an error is raised
- If unexpected parameters are passed, an error is raised
To accept keys that are not valid Python identifiers (e.g.
data-id
), or would conflict with Python keywords (e.g.is
), you can use the**kwargs
syntax:@template_tag(library, tag=\"greet\")\ndef greet(\n node: BaseNode,\n context: Context,\n **kwargs,\n) -> str:\n attrs = kwargs.copy()\n is_var = attrs.pop(\"is\", None)\n attrs_str = \" \".join(f'{k}=\"{v}\"' for k, v in attrs.items())\n\n return mark_safe(f\"\"\"\n <div {attrs_str}>\n Hello, {is_var}!\n </div>\n \"\"\")\n
This allows you to use the tag like this:
"},{"location":"concepts/advanced/template_tags/#defining-template-tags-with-basenode","title":"Defining template tags with{% greet is=\"John\" data-id=\"123\" %}\n
BaseNode
","text":"For more control over your template tag, you can subclass
BaseNode
directly instead of using the decorator. This gives you access to additional features like the node's internal state and parsing details.
"},{"location":"concepts/advanced/template_tags/#node-properties","title":"Node properties","text":"from django_components import BaseNode\n\nclass GreetNode(BaseNode):\n tag = \"greet\"\n end_tag = \"endgreet\"\n allowed_flags = [\"required\"]\n\n def render(self, context: Context, name: str, **kwargs) -> str:\n # Access node properties\n if self.flags[\"required\"]:\n return f\"Required greeting: Hello, {name}!\"\n return f\"Hello, {name}!\"\n\n# Register the node\nGreetNode.register(library)\n
When using
BaseNode
, you have access to several useful properties:node_id
: A unique identifier for this node instanceflags
: Dictionary of flag values (e.g.{\"required\": True}
)params
: List of raw parameters passed to the tagnodelist
: The template nodes between the start and end tagsactive_flags
: List of flags that are currently set to True
This is what the
"},{"location":"concepts/advanced/template_tags/#rendering-content-between-tags","title":"Rendering content between tags","text":"node
parameter in the@template_tag
decorator gives you access to - it's the instance of the node class that was automatically created for your template tag.When your tag has an end tag, you can access and render the content between the tags using
nodelist
:
"},{"location":"concepts/advanced/template_tags/#unregistering-nodes","title":"Unregistering nodes","text":"class WrapNode(BaseNode):\n tag = \"wrap\"\n end_tag = \"endwrap\"\n\n def render(self, context: Context, tag: str = \"div\", **attrs) -> str:\n # Render the content between tags\n inner = self.nodelist.render(context)\n attrs_str = \" \".join(f'{k}=\"{v}\"' for k, v in attrs.items())\n return f\"<{tag} {attrs_str}>{inner}</{tag}>\"\n\n# Usage:\n{% wrap tag=\"section\" class=\"content\" %}\n Hello, world!\n{% endwrap %}\n
You can unregister a node from a library using the
unregister
method:GreetNode.unregister(library)\n
This is particularly useful in testing when you want to clean up after registering temporary tags.
"},{"location":"concepts/advanced/typing_and_validation/","title":"Typing and validation","text":""},{"location":"concepts/advanced/typing_and_validation/#adding-type-hints-with-generics","title":"Adding type hints with Generics","text":"New in version 0.92
The
Component
class optionally accepts type parameters that allow you to specify the types of args, kwargs, slots, and data:class Button(Component[Args, Kwargs, Slots, Data, JsData, CssData]):\n ...\n
Args
- Must be aTuple
orAny
Kwargs
- Must be aTypedDict
orAny
Data
- Must be aTypedDict
orAny
Slots
- Must be aTypedDict
orAny
Here's a full example:
from typing import NotRequired, Tuple, TypedDict, SlotContent, SlotFunc\n\n# Positional inputs\nArgs = Tuple[int, str]\n\n# Kwargs inputs\nclass Kwargs(TypedDict):\n variable: str\n another: int\n maybe_var: NotRequired[int] # May be ommited\n\n# Data returned from `get_context_data`\nclass Data(TypedDict):\n variable: str\n\n# The data available to the `my_slot` scoped slot\nclass MySlotData(TypedDict):\n value: int\n\n# Slots\nclass Slots(TypedDict):\n # Use SlotFunc for slot functions.\n # The generic specifies the `data` dictionary\n my_slot: NotRequired[SlotFunc[MySlotData]]\n # SlotContent == Union[str, SafeString]\n another_slot: SlotContent\n\nclass Button(Component[Args, Kwargs, Slots, Data, JsData, CssData]):\n def get_context_data(self, variable, another):\n return {\n \"variable\": variable,\n }\n
When you then call
Component.render
orComponent.render_to_response
, you will get type hints:
"},{"location":"concepts/advanced/typing_and_validation/#usage-for-python-311","title":"Usage for Python <3.11","text":"Button.render(\n # Error: First arg must be `int`, got `float`\n args=(1.25, \"abc\"),\n # Error: Key \"another\" is missing\n kwargs={\n \"variable\": \"text\",\n },\n)\n
On Python 3.8-3.10, use
typing_extensions
from typing_extensions import TypedDict, NotRequired\n
Additionally on Python 3.8-3.9, also import
annotations
:from __future__ import annotations\n
Moreover, on 3.10 and less, you may not be able to use
NotRequired
, and instead you will need to mark either all keys are required, or all keys as optional, using TypeDict'stotal
kwarg.See PEP-655 for more info.
"},{"location":"concepts/advanced/typing_and_validation/#passing-additional-args-or-kwargs","title":"Passing additional args or kwargs","text":"You may have a function that supports any number of args or kwargs:
def get_context_data(self, *args, **kwargs):\n ...\n
This is not supported with the typed components.
As a workaround:
- For
*args
, set a positional argument that accepts a list of values:
# Tuple of one member of list of strings\nArgs = Tuple[List[str]]\n
- For
*kwargs
, set a keyword argument that accepts a dictionary of values:
"},{"location":"concepts/advanced/typing_and_validation/#handling-no-args-or-no-kwargs","title":"Handling no args or no kwargs","text":"class Kwargs(TypedDict):\n variable: str\n another: int\n # Pass any extra keys under `extra`\n extra: Dict[str, any]\n
To declare that a component accepts no Args, Kwargs, etc, you can use
EmptyTuple
andEmptyDict
types:
"},{"location":"concepts/advanced/typing_and_validation/#runtime-input-validation-with-types","title":"Runtime input validation with types","text":"from django_components import Component, EmptyDict, EmptyTuple\n\nArgs = EmptyTuple\nKwargs = Data = Slots = EmptyDict\n\nclass Button(Component[Args, Kwargs, Slots, Data, JsData, CssData]):\n ...\n
New in version 0.96
NOTE: Kwargs, slots, and data validation is supported only for Python >=3.11
In Python 3.11 and later, when you specify the component types, you will get also runtime validation of the inputs you pass to
Component.render
orComponent.render_to_response
.So, using the example from before, if you ignored the type errors and still ran the following code:
Button.render(\n # Error: First arg must be `int`, got `float`\n args=(1.25, \"abc\"),\n # Error: Key \"another\" is missing\n kwargs={\n \"variable\": \"text\",\n },\n)\n
This would raise a
TypeError
:Component 'Button' expected positional argument at index 0 to be <class 'int'>, got 1.25 of type <class 'float'>\n
In case you need to skip these errors, you can either set the faulty member to
Any
, e.g.:# Changed `int` to `Any`\nArgs = Tuple[Any, str]\n
Or you can replace
Args
withAny
altogether, to skip the validation of args:# Replaced `Args` with `Any`\nclass Button(Component[Any, Kwargs, Slots, Data, JsData, CssData]):\n ...\n
Same applies to kwargs, data, and slots.
"},{"location":"concepts/fundamentals/access_component_input/","title":"Accessing component inputs","text":"When you call
Component.render
orComponent.render_to_response
, the inputs to these methods can be accessed from within the instance underself.input
.This means that you can use
self.input
inside:get_context_data
get_template_name
get_template
on_render_before
on_render_after
self.input
is only defined during the execution ofComponent.render
, and raises aRuntimeError
when called outside of this context.self.input
has the same fields as the input toComponent.render
:class TestComponent(Component):\n def get_context_data(self, var1, var2, variable, another, **attrs):\n assert self.input.args == (123, \"str\")\n assert self.input.kwargs == {\"variable\": \"test\", \"another\": 1}\n assert self.input.slots == {\"my_slot\": \"MY_SLOT\"}\n assert isinstance(self.input.context, Context)\n\n return {\n \"variable\": variable,\n }\n\nrendered = TestComponent.render(\n kwargs={\"variable\": \"test\", \"another\": 1},\n args=(123, \"str\"),\n slots={\"my_slot\": \"MY_SLOT\"},\n)\n
NOTE: The slots in
"},{"location":"concepts/fundamentals/autodiscovery/","title":"Autodiscovery","text":"self.input.slots
are normalized to slot functions.Every component that you want to use in the template with the
{% component %}
tag needs to be registered with theComponentRegistry
. Normally, we use the@register
decorator for that:from django_components import Component, register\n\n@register(\"calendar\")\nclass Calendar(Component):\n ...\n
But for the component to be registered, the code needs to be executed - and for that, the file needs to be imported as a module.
One way to do that is by importing all your components in
apps.py
:from django.apps import AppConfig\n\nclass MyAppConfig(AppConfig):\n name = \"my_app\"\n\n def ready(self) -> None:\n from components.card.card import Card\n from components.list.list import List\n from components.menu.menu import Menu\n from components.button.button import Button\n ...\n
However, there's a simpler way!
By default, the Python files in the
COMPONENTS.dirs
directories (and app-level[app]/components/
) are auto-imported in order to auto-register the components.Autodiscovery occurs when Django is loaded, during the
AppConfig.ready
hook of theapps.py
file.If you are using autodiscovery, keep a few points in mind:
- Avoid defining any logic on the module-level inside the
components
dir, that you would not want to run anyway. - Components inside the auto-imported files still need to be registered with
@register
- Auto-imported component files must be valid Python modules, they must use suffix
.py
, and module name should follow PEP-8. - Subdirectories and files starting with an underscore
_
(except__init__.py
) are ignored.
Autodiscovery can be disabled in the settings.
"},{"location":"concepts/fundamentals/autodiscovery/#manually-trigger-autodiscovery","title":"Manually trigger autodiscovery","text":"Autodiscovery can be also triggered manually, using the
autodiscover
function. This is useful if you want to run autodiscovery at a custom point of the lifecycle:from django_components import autodiscover\n\nautodiscover()\n
To get the same list of modules that
autodiscover()
would return, but without importing them, useget_component_files()
:
"},{"location":"concepts/fundamentals/component_context_scope/","title":"Component context and scope","text":"from django_components import get_component_files\n\nmodules = get_component_files(\".py\")\n
By default, context variables are passed down the template as in regular Django - deeper scopes can access the variables from the outer scopes. So if you have several nested forloops, then inside the deep-most loop you can access variables defined by all previous loops.
With this in mind, the
{% component %}
tag behaves similarly to{% include %}
tag - inside the component tag, you can access all variables that were defined outside of it.And just like with
{% include %}
, if you don't want a specific component template to have access to the parent context, addonly
to the{% component %}
tag:{% component \"calendar\" date=\"2015-06-19\" only / %}\n
NOTE:
{% csrf_token %}
tags need access to the top-level context, and they will not function properly if they are rendered in a component that is called with theonly
modifier.If you find yourself using the
only
modifier often, you can set the context_behavior option to\"isolated\"
, which automatically applies theonly
modifier. This is useful if you want to make sure that components don't accidentally access the outer context.Components can also access the outer context in their context methods like
"},{"location":"concepts/fundamentals/component_context_scope/#example-of-accessing-outer-context","title":"Example of Accessing Outer Context","text":"get_context_data
by accessing the propertyself.outer_context
.<div>\n {% component \"calender\" / %}\n</div>\n
Assuming that the rendering context has variables such as
date
, you can useself.outer_context
to access them from withinget_context_data
. Here's how you might implement it:class Calender(Component):\n\n ...\n\n def get_context_data(self):\n outer_field = self.outer_context[\"date\"]\n return {\n \"date\": outer_fields,\n }\n
However, as a best practice, it\u2019s recommended not to rely on accessing the outer context directly through
"},{"location":"concepts/fundamentals/component_context_scope/#context-behavior","title":"Context behavior","text":"self.outer_context
. Instead, explicitly pass the variables to the component. For instance, continue passing the variables in the component tag as shown in the previous examples.django_components supports both Django and Vue-like behavior when it comes to passing data to and through components. This can be configured in context_behavior.
This has two modes:
-
\"django\"
The default Django template behavior.
Inside the
{% fill %}
tag, the context variables you can access are a union of:- All the variables that were OUTSIDE the fill tag, including any\\
{% with %}
tags. - Any loops (
{% for ... %}
) that the{% fill %}
tag is part of. - Data returned from
Component.get_context_data()
of the component that owns the fill tag.
- All the variables that were OUTSIDE the fill tag, including any\\
-
\"isolated\"
Similar behavior to Vue or React, this is useful if you want to make sure that components don't accidentally access variables defined outside of the component.
Inside the
{% fill %}
tag, you can ONLY access variables from 2 places:- Any loops (
{% for ... %}
) that the{% fill %}
tag is part of. Component.get_context_data()
of the component which defined the template (AKA the \"root\" component).
- Any loops (
Warning
Notice that the component whose
get_context_data()
we use inside{% fill %}
is NOT the same across the two modes!Consider this example:
class Outer(Component):\n template = \\\"\\\"\\\"\n <div>\n {% component \"inner\" %}\n {% fill \"content\" %}\n {{ my_var }}\n {% endfill %}\n {% endcomponent %}\n </div>\n \\\"\\\"\\\"\n
-
\"django\"
-my_var
has access to data fromget_context_data()
of bothInner
andOuter
. If there are variables defined in both, thenInner
overshadowsOuter
. -
\"isolated\"
-my_var
has access to data fromget_context_data()
of ONLYOuter
.
Given this template:
@register(\"root_comp\")\nclass RootComp(Component):\n template = \"\"\"\n {% with cheese=\"feta\" %}\n {% component 'my_comp' %}\n {{ my_var }} # my_var\n {{ cheese }} # cheese\n {% endcomponent %}\n {% endwith %}\n \"\"\"\n\n def get_context_data(self):\n return { \"my_var\": 123 }\n
Then if
get_context_data()
of the component\"my_comp\"
returns following data:{ \"my_var\": 456 }\n
Then the template will be rendered as:
456 # my_var\nfeta # cheese\n
Because
\"my_comp\"
overshadows the outer variable\"my_var\"
, so{{ my_var }}
equals456
.And variable
"},{"location":"concepts/fundamentals/component_context_scope/#example-isolated","title":"Example \"isolated\"","text":"\"cheese\"
equalsfeta
, because the fill CAN access all the data defined in the outer layers, like the{% with %}
tag.Given this template:
class RootComp(Component):\n template = \"\"\"\n {% with cheese=\"feta\" %}\n {% component 'my_comp' %}\n {{ my_var }} # my_var\n {{ cheese }} # cheese\n {% endcomponent %}\n {% endwith %}\n \"\"\"\n\n def get_context_data(self):\n return { \"my_var\": 123 }\n
Then if
get_context_data()
of the component\"my_comp\"
returns following data:{ \"my_var\": 456 }\n
Then the template will be rendered as:
123 # my_var\n # cheese\n
Because variables
\"my_var\"
and\"cheese\"
are searched only insideRootComponent.get_context_data()
. But since\"cheese\"
is not defined there, it's empty.Info
Notice that the variables defined with the
"},{"location":"concepts/fundamentals/components_as_views/","title":"Components as views","text":"{% with %}
tag are ignored inside the{% fill %}
tag with the\"isolated\"
mode.New in version 0.34
Note: Since 0.92, Component no longer subclasses View. To configure the View class, set the nested
Component.View
classComponents can now be used as views:
-
Components define the
Component.as_view()
class method that can be used the same asView.as_view()
. -
By default, you can define GET, POST or other HTTP handlers directly on the Component, same as you do with View. For example, you can override
get
andpost
to handle GET and POST requests, respectively. -
In addition,
Component
now has arender_to_response
method that renders the component template based on the provided context and slots' data and returns anHttpResponse
object.
Here's an example of a calendar component defined as a view:
# In a file called [project root]/components/calendar.py\nfrom django_components import Component, ComponentView, register\n\n@register(\"calendar\")\nclass Calendar(Component):\n\n template = \"\"\"\n <div class=\"calendar-component\">\n <div class=\"header\">\n {% slot \"header\" / %}\n </div>\n <div class=\"body\">\n Today's date is <span>{{ date }}</span>\n </div>\n </div>\n \"\"\"\n\n # Handle GET requests\n def get(self, request, *args, **kwargs):\n context = {\n \"date\": request.GET.get(\"date\", \"2020-06-06\"),\n }\n slots = {\n \"header\": \"Calendar header\",\n }\n # Return HttpResponse with the rendered content\n return self.render_to_response(\n context=context,\n slots=slots,\n )\n
Then, to use this component as a view, you should create a
urls.py
file in your components directory, and add a path to the component's view:# In a file called [project root]/components/urls.py\nfrom django.urls import path\nfrom components.calendar.calendar import Calendar\n\nurlpatterns = [\n path(\"calendar/\", Calendar.as_view()),\n]\n
Component.as_view()
is a shorthand for callingView.as_view()
and passing the component instance as one of the arguments.Remember to add
__init__.py
to your components directory, so that Django can find theurls.py
file.Finally, include the component's urls in your project's
urls.py
file:# In a file called [project root]/urls.py\nfrom django.urls import include, path\n\nurlpatterns = [\n path(\"components/\", include(\"components.urls\")),\n]\n
Note: Slots content are automatically escaped by default to prevent XSS attacks. To disable escaping, set
escape_slots_content=False
in therender_to_response
method. If you do so, you should make sure that any content you pass to the slots is safe, especially if it comes from user input.If you're planning on passing an HTML string, check Django's use of
"},{"location":"concepts/fundamentals/components_as_views/#modifying-the-view-class","title":"Modifying the View class","text":"format_html
andmark_safe
.The View class that handles the requests is defined on
Component.View
.When you define a GET or POST handlers on the
Component
class, like so:class MyComponent(Component):\n def get(self, request, *args, **kwargs):\n return self.render_to_response(\n context={\n \"date\": request.GET.get(\"date\", \"2020-06-06\"),\n },\n )\n\n def post(self, request, *args, **kwargs) -> HttpResponse:\n variable = request.POST.get(\"variable\")\n return self.render_to_response(\n kwargs={\"variable\": variable}\n )\n
Then the request is still handled by
Component.View.get()
orComponent.View.post()
methods. However, by default,Component.View.get()
points toComponent.get()
, and so on.class ComponentView(View):\n component: Component = None\n ...\n\n def get(self, request, *args, **kwargs):\n return self.component.get(request, *args, **kwargs)\n\n def post(self, request, *args, **kwargs):\n return self.component.post(request, *args, **kwargs)\n\n ...\n
If you want to define your own
View
class, you need to:- Set the class as
Component.View
- Subclass from
ComponentView
, so the View instance has access to the component instance.
In the example below, we added extra logic into
View.setup()
.Note that the POST handler is still defined at the top. This is because
View
subclassesComponentView
, which defines thepost()
method that callsComponent.post()
.If you were to overwrite the
View.post()
method, thenComponent.post()
would be ignored.
"},{"location":"concepts/fundamentals/components_in_python/","title":"Components in Python","text":"from django_components import Component, ComponentView\n\nclass MyComponent(Component):\n\n def post(self, request, *args, **kwargs) -> HttpResponse:\n variable = request.POST.get(\"variable\")\n return self.component.render_to_response(\n kwargs={\"variable\": variable}\n )\n\n class View(ComponentView):\n def setup(self, request, *args, **kwargs):\n super(request, *args, **kwargs)\n\n do_something_extra(request, *args, **kwargs)\n
New in version 0.81
Components can be rendered outside of Django templates, calling them as regular functions (\"React-style\").
The component class defines
render
andrender_to_response
class methods. These methods accept positional args, kwargs, and slots, offering the same flexibility as the{% component %}
tag:class SimpleComponent(Component):\n template = \"\"\"\n {% load component_tags %}\n hello: {{ hello }}\n foo: {{ foo }}\n kwargs: {{ kwargs|safe }}\n slot_first: {% slot \"first\" required / %}\n \"\"\"\n\n def get_context_data(self, arg1, arg2, **kwargs):\n return {\n \"hello\": arg1,\n \"foo\": arg2,\n \"kwargs\": kwargs,\n }\n\nrendered = SimpleComponent.render(\n args=[\"world\", \"bar\"],\n kwargs={\"kw1\": \"test\", \"kw2\": \"ooo\"},\n slots={\"first\": \"FIRST_SLOT\"},\n context={\"from_context\": 98},\n)\n
Renders:
"},{"location":"concepts/fundamentals/components_in_python/#inputs-of-render-and-render_to_response","title":"Inputs ofhello: world\nfoo: bar\nkwargs: {'kw1': 'test', 'kw2': 'ooo'}\nslot_first: FIRST_SLOT\n
render
andrender_to_response
","text":"Both
render
andrender_to_response
accept the same input:Component.render(\n context: Mapping | django.template.Context | None = None,\n args: List[Any] | None = None,\n kwargs: Dict[str, Any] | None = None,\n slots: Dict[str, str | SafeString | SlotFunc] | None = None,\n escape_slots_content: bool = True\n) -> str:\n
-
args
- Positional args for the component. This is the same as calling the component as{% component \"my_comp\" arg1 arg2 ... %}
-
kwargs
- Keyword args for the component. This is the same as calling the component as{% component \"my_comp\" key1=val1 key2=val2 ... %}
-
slots
- Component slot fills. This is the same as pasing{% fill %}
tags to the component. Accepts a dictionary of{ slot_name: slot_content }
whereslot_content
can be a string orSlotFunc
. -
escape_slots_content
- Whether the content fromslots
should be escaped.True
by default to prevent XSS attacks. If you disable escaping, you should make sure that any content you pass to the slots is safe, especially if it comes from user input. -
context
- A context (dictionary or Django's Context) within which the component is rendered. The keys on the context can be accessed from within the template. -
NOTE: In \"isolated\" mode, context is NOT accessible, and data MUST be passed via component's args and kwargs.
-
request
- A Django request object. This is used to enable Django templatecontext_processors
to run, allowing for template tags like{% csrf_token %}
and variables like{{ debug }}
. - Similar behavior can be achieved with provide / inject.
- This is used internally to convert
context
to a RequestContext. It does nothing ifcontext
is already aContext
instance.
SlotFunc
","text":"When rendering components with slots in
render
orrender_to_response
, you can pass either a string or a function.The function has following signature:
def render_func(\n context: Context,\n data: Dict[str, Any],\n slot_ref: SlotRef,\n) -> str | SafeString:\n return nodelist.render(ctx)\n
context
- Django's Context available to the Slot Node.data
- Data passed to the{% slot %}
tag. See Scoped Slots.slot_ref
- The default slot content. See Accessing original content of slots.- NOTE: The slot is lazily evaluated. To render the slot, convert it to string with
str(slot_ref)
.
Example:
"},{"location":"concepts/fundamentals/components_in_python/#response-class-of-render_to_response","title":"Response class ofdef footer_slot(ctx, data, slot_ref):\n return f\"\"\"\n SLOT_DATA: {data['abc']}\n ORIGINAL: {slot_ref}\n \"\"\"\n\nMyComponent.render_to_response(\n slots={\n \"footer\": footer_slot,\n },\n)\n
render_to_response
","text":"While
render
method returns a plain string,render_to_response
wraps the rendered content in a \"Response\" class. By default, this isdjango.http.HttpResponse
.If you want to use a different Response class in
render_to_response
, set theComponent.response_class
attribute:
"},{"location":"concepts/fundamentals/defining_js_css_html_files/","title":"Defining HTML / JS / CSS files","text":"class MyResponse(HttpResponse):\n def __init__(self, *args, **kwargs) -> None:\n super().__init__(*args, **kwargs)\n # Configure response\n self.headers = ...\n self.status = ...\n\nclass SimpleComponent(Component):\n response_class = MyResponse\n template: types.django_html = \"HELLO\"\n\nresponse = SimpleComponent.render_to_response()\nassert isinstance(response, MyResponse)\n
As you could have seen in the tutorial, there's multiple ways how you can associate HTML / JS / CSS with a component:
- You can set
Component.template
,Component.css
andComponent.js
to define the main HTML / CSS / JS for a component as inlined code. - You can set
Component.template_file
,Component.css_file
andComponent.js_file
to define the main HTML / CSS / JS for a component in separate files. - You can link additional CSS / JS files using
Component.Media.js
andComponent.Media.css
.
Warning
You cannot use both inlined code and separate file for a single language type:
- You can only either set
Component.template
orComponent.template_file
- You can only either set
Component.css
orComponent.css_file
- You can only either set
Component.js
orComponent.js_file
However, you can freely mix these for different languages:
class MyTable(Component):\n template: types.django_html = \"\"\"\n <div class=\"welcome\">\n Hi there!\n </div>\n \"\"\"\n js_file = \"my_table.js\"\n css_file = \"my_table.css\"\n
Note
django-component's management of files is inspired by Django's
Media
class.To be familiar with how Django handles static files, we recommend reading also:
- How to manage static files (e.g. images, JavaScript, CSS)
As seen in the getting started example, to associate HTML / JS / CSS files with a component, you can set them as
[project root]/components/calendar/calendar.pyComponent.template_file
,Component.js_file
andComponent.css_file
respectively:from django_components import Component, register\n\n@register(\"calendar\")\nclass Calendar(Component):\n template_file = \"template.html\"\n css_file = \"style.css\"\n js_file = \"script.js\"\n
In the example above, we defined the files relative to the directory where the component file is defined.
Alternatively, you can specify the file paths relative to the directories set in
COMPONENTS.dirs
orCOMPONENTS.app_dirs
.If you specify the paths relative to component's directory, django-componenents does the conversion automatically for you.
Thus, assuming that
[project root]/components/calendar/calendar.pyCOMPONENTS.dirs
contains path[project root]/components
, the example above is the same as writing:from django_components import Component, register\n\n@register(\"calendar\")\nclass Calendar(Component):\n template_file = \"calendar/template.html\"\n css_file = \"calendar/style.css\"\n js_file = \"calendar/script.js\"\n
Important
File path resolution in-depth
At component class creation, django-components checks all file paths defined on the component (e.g.
Component.template_file
).For each file path, it checks if the file path is relative to the component's directory. And such file exists, the component's file path is re-written to be defined relative to a first matching directory in
COMPONENTS.dirs
orCOMPONENTS.app_dirs
.Example:
[root]/components/mytable/mytable.pyclass MyTable(Component):\n template_file = \"mytable.html\"\n
- Component
MyTable
is defined in file[root]/components/mytable/mytable.py
. - The component's directory is thus
[root]/components/mytable/
. - Because
MyTable.template_file
ismytable.html
, django-components tries to resolve it as[root]/components/mytable/mytable.html
. - django-components checks the filesystem. If there's no such file, nothing happens.
- If there IS such file, django-components tries to rewrite the path.
- django-components searches
COMPONENTS.dirs
andCOMPONENTS.app_dirs
for a first directory that contains[root]/components/mytable/mytable.html
. - It comes across
[root]/components/
, which DOES contain the path tomytable.html
. - Thus, it rewrites
template_file
frommytable.html
tomytable/mytable.html
.
NOTE: In case of ambiguity, the preference goes to resolving the files relative to the component's directory.
"},{"location":"concepts/fundamentals/defining_js_css_html_files/#defining-additional-js-and-css-files","title":"Defining additional JS and CSS files","text":"Each component can have only a single template, and single main JS and CSS. However, you can define additional JS or CSS using the nested
Component.Media
class.This
Media
class behaves similarly to Django's Media class:- Paths are generally handled as static file paths, and resolved URLs are rendered to HTML with
media_class.render_js()
ormedia_class.render_css()
. - A path that starts with
http
,https
, or/
is considered a URL, skipping the static file resolution. This path is still rendered to HTML withmedia_class.render_js()
ormedia_class.render_css()
. - A
SafeString
, or a function (with__html__
method) is considered an already-formatted HTML tag, skipping both static file resolution and rendering withmedia_class.render_js()
ormedia_class.render_css()
. - You can set
extend
to configure whether to inherit JS / CSS from parent components. See Controlling Media Inheritance.
However, there's a few differences from Django's Media class:
- Our Media class accepts various formats for the JS and CSS files: either a single file, a list, or (CSS-only) a dictonary (See
ComponentMediaInput
). - Individual JS / CSS files can be any of
str
,bytes
,Path
,SafeString
, or a function (SeeComponentMediaInputPath
).
"},{"location":"concepts/fundamentals/defining_js_css_html_files/#configuring-css-media-types","title":"Configuring CSS Media Types","text":"class MyTable(Component):\n class Media:\n js = [\n \"path/to/script.js\",\n \"https://unpkg.com/alpinejs@3.14.7/dist/cdn.min.js\", # AlpineJS\n ]\n css = {\n \"all\": [\n \"path/to/style.css\",\n \"https://unpkg.com/tailwindcss@^2/dist/tailwind.min.css\", # TailwindCSS\n ],\n \"print\": [\"path/to/style2.css\"],\n }\n
You can define which stylesheets will be associated with which CSS Media types. You do so by defining CSS files as a dictionary.
See the corresponding Django Documentation.
Again, you can set either a single file or a list of files per media type:
class MyComponent(Component):\n class Media:\n css = {\n \"all\": \"path/to/style1.css\",\n \"print\": [\"path/to/style2.css\", \"path/to/style3.css\"],\n }\n
Note
When you define CSS as a string or a list, the
all
media type is implied.So these two examples are the same:
class MyComponent(Component):\n class Media:\n css = \"path/to/style1.css\"\n
"},{"location":"concepts/fundamentals/defining_js_css_html_files/#supported-types-for-file-paths","title":"Supported types for file paths","text":"class MyComponent(Component):\n class Media:\n css = {\n \"all\": [\"path/to/style1.css\"],\n }\n
File paths can be any of:
str
bytes
PathLike
(__fspath__
method)SafeData
(__html__
method)Callable
that returns any of the above, evaluated at class creation (__new__
)
See
ComponentMediaInputPath
.
"},{"location":"concepts/fundamentals/defining_js_css_html_files/#paths-as-objects","title":"Paths as objects","text":"from pathlib import Path\n\nfrom django.utils.safestring import mark_safe\n\nclass SimpleComponent(Component):\n class Media:\n css = [\n mark_safe('<link href=\"/static/calendar/style1.css\" rel=\"stylesheet\" />'),\n Path(\"calendar/style1.css\"),\n \"calendar/style2.css\",\n b\"calendar/style3.css\",\n lambda: \"calendar/style4.css\",\n ]\n js = [\n mark_safe('<script src=\"/static/calendar/script1.js\"></script>'),\n Path(\"calendar/script1.js\"),\n \"calendar/script2.js\",\n b\"calendar/script3.js\",\n lambda: \"calendar/script4.js\",\n ]\n
In the example above, you can see that when we used Django's
mark_safe()
to mark a string as aSafeString
, we had to define the full<script>
/<link>
tag.This is an extension of Django's Paths as objects feature, where \"safe\" strings are taken as is, and accessed only at render time.
Because of that, the paths defined as \"safe\" strings are NEVER resolved, neither relative to component's directory, nor relative to
COMPONENTS.dirs
.\"Safe\" strings can be used to lazily resolve a path, or to customize the
<script>
or<link>
tag for individual paths:In the example below, we make use of \"safe\" strings to add
type=\"module\"
to the script tag that will fetchcalendar/script2.js
. In this case, we implemented a \"safe\" string by defining a__html__
method.
"},{"location":"concepts/fundamentals/defining_js_css_html_files/#customize-how-paths-are-rendered-into-html-tags","title":"Customize how paths are rendered into HTML tags","text":"class ModuleJsPath:\n def __init__(self, static_path: str) -> None:\n self.static_path = static_path\n\n def __html__(self):\n full_path = static(self.static_path)\n return format_html(\n f'<script type=\"module\" src=\"{full_path}\"></script>'\n )\n\n@register(\"calendar\")\nclass Calendar(Component):\n template_file = \"calendar/template.html\"\n\n def get_context_data(self, date):\n return {\n \"date\": date,\n }\n\n class Media:\n css = \"calendar/style1.css\"\n js = [\n # <script> tag constructed by Media class\n \"calendar/script1.js\",\n # Custom <script> tag\n ModuleJsPath(\"calendar/script2.js\"),\n ]\n
Sometimes you may need to change how all CSS
<link>
or JS<script>
tags are rendered for a given component. You can achieve this by providing your own subclass of Django'sMedia
class to component'smedia_class
attribute.Normally, the JS and CSS paths are passed to
Media
class, which decides how the paths are resolved and how the<link>
and<script>
tags are constructed.To change how the tags are constructed, you can override the
Media.render_js
andMedia.render_css
methods:
"},{"location":"concepts/fundamentals/defining_js_css_html_files/#accessing-components-html-js-css","title":"Accessing component's HTML / JS / CSS","text":"from django.forms.widgets import Media\nfrom django_components import Component, register\n\nclass MyMedia(Media):\n # Same as original Media.render_js, except\n # the `<script>` tag has also `type=\"module\"`\n def render_js(self):\n tags = []\n for path in self._js:\n if hasattr(path, \"__html__\"):\n tag = path.__html__()\n else:\n tag = format_html(\n '<script type=\"module\" src=\"{}\"></script>',\n self.absolute_path(path)\n )\n return tags\n\n@register(\"calendar\")\nclass Calendar(Component):\n template_file = \"calendar/template.html\"\n css_file = \"calendar/style.css\"\n js_file = \"calendar/script.js\"\n\n class Media:\n css = \"calendar/style1.css\"\n js = \"calendar/script2.js\"\n\n # Override the behavior of Media class\n media_class = MyMedia\n
Component's HTML / CSS / JS is resolved and loaded lazily.
This means that, when you specify any of
template_file
,js_file
,css_file
, orMedia.js/css
, these file paths will be resolved only once you either:-
Access any of the following attributes on the component:
media
,template
,template_file
,js
,js_file
,css
,css_file
-
Render the component.
Once the component's media files have been loaded once, they will remain in-memory on the Component class:
- HTML from
Component.template_file
will be available underComponent.template
- CSS from
Component.css_file
will be available underComponent.css
- JS from
Component.js_file
will be available underComponent.js
Thus, whether you define HTML via
Component.template_file
orComponent.template
, you can always access the HTML content underComponent.template
. And the same applies for JS and CSS.Example:
# When we create Calendar component, the files like `calendar/template.html`\n# are not yet loaded!\n@register(\"calendar\")\nclass Calendar(Component):\n template_file = \"calendar/template.html\"\n css_file = \"calendar/style.css\"\n js_file = \"calendar/script.js\"\n\n class Media:\n css = \"calendar/style1.css\"\n js = \"calendar/script2.js\"\n\n# It's only at this moment that django-components reads the files like `calendar/template.html`\nprint(Calendar.css)\n# Output:\n# .calendar {\n# width: 200px;\n# background: pink;\n# }\n
Warning
Do NOT modify HTML / CSS / JS after it has been loaded
django-components assumes that the component's media files like
js_file
orMedia.js/css
are static.If you need to dynamically change these media files, consider instead defining multiple Components.
Modifying these files AFTER the component has been loaded at best does nothing. However, this is an untested behavior, which may lead to unexpected errors.
"},{"location":"concepts/fundamentals/defining_js_css_html_files/#accessing-components-media-files","title":"Accessing component's Media files","text":"To access the files that you defined under
Component.Media
, useComponent.media
(lowercase). This is consistent behavior with Django's Media class.
"},{"location":"concepts/fundamentals/defining_js_css_html_files/#componentmedia-vs-componentmedia","title":"class MyComponent(Component):\n class Media:\n js = \"path/to/script.js\"\n css = \"path/to/style.css\"\n\nprint(MyComponent.media)\n# Output:\n# <script src=\"/static/path/to/script.js\"></script>\n# <link href=\"/static/path/to/style.css\" media=\"all\" rel=\"stylesheet\">\n
Component.Media
vsComponent.media
","text":"When working with component media files, there are a few important concepts to understand:
-
Component.Media
- Is the \"raw\" media definition, or the input, which holds only the component's own media definition
- This class is NOT instantiated, it merely holds the JS / CSS files.
-
Component.media
- Returns all resolved media files, including those inherited from parent components
- Is an instance of
Component.media_class
class ParentComponent(Component):\n class Media:\n js = [\"parent.js\"]\n\nclass ChildComponent(ParentComponent):\n class Media:\n js = [\"child.js\"]\n\n# Access only this component's media\nprint(ChildComponent.Media.js) # [\"child.js\"]\n\n# Access all inherited media\nprint(ChildComponent.media._js) # [\"parent.js\", \"child.js\"]\n
Note
You should not manually modify
Component.media
orComponent.Media
after the component has been resolved, as this may lead to unexpected behavior.If you want to modify the class that is instantiated for
"},{"location":"concepts/fundamentals/defining_js_css_html_files/#controlling-media-inheritance","title":"Controlling Media Inheritance","text":"Component.media
, you can configureComponent.media_class
(See example).By default, the media files are inherited from the parent component.
class ParentComponent(Component):\n class Media:\n js = [\"parent.js\"]\n\nclass MyComponent(ParentComponent):\n class Media:\n js = [\"script.js\"]\n\nprint(MyComponent.media._js) # [\"parent.js\", \"script.js\"]\n
You can set the component NOT to inherit from the parent component by setting the
extend
attribute toFalse
:class ParentComponent(Component):\n class Media:\n js = [\"parent.js\"]\n\nclass MyComponent(ParentComponent):\n class Media:\n extend = False # Don't inherit parent media\n js = [\"script.js\"]\n\nprint(MyComponent.media._js) # [\"script.js\"]\n
Alternatively, you can specify which components to inherit from. In such case, the media files are inherited ONLY from the specified components, and NOT from the original parent components:
class ParentComponent(Component):\n class Media:\n js = [\"parent.js\"]\n\nclass MyComponent(ParentComponent):\n class Media:\n # Only inherit from these, ignoring the files from the parent\n extend = [OtherComponent1, OtherComponent2]\n\n js = [\"script.js\"]\n\nprint(MyComponent.media._js) # [\"script.js\", \"other1.js\", \"other2.js\"]\n
Info
The
extend
behaves consistently with Django's Media class, with one exception:- When you set
extend
to a list, the list is expected to contain Component classes (or other classes that have a nestedMedia
class).
New in version 0.74:
You can use the
html_attrs
tag to render HTML attributes, given a dictionary of values.So if you have a template:
<div class=\"{{ classes }}\" data-id=\"{{ my_id }}\">\n</div>\n
You can simplify it with
html_attrs
tag:<div {% html_attrs attrs %}>\n</div>\n
where
attrs
is:attrs = {\n \"class\": classes,\n \"data-id\": my_id,\n}\n
This feature is inspired by
"},{"location":"concepts/fundamentals/html_attributes/#removing-atttributes","title":"Removing atttributes","text":"merge_attrs
tag of django-web-components and \"fallthrough attributes\" feature of Vue.Attributes that are set to
None
orFalse
are NOT rendered.So given this input:
attrs = {\n \"class\": \"text-green\",\n \"required\": False,\n \"data-id\": None,\n}\n
And template:
<div {% html_attrs attrs %}>\n</div>\n
Then this renders:
"},{"location":"concepts/fundamentals/html_attributes/#boolean-attributes","title":"Boolean attributes","text":"<div class=\"text-green\"></div>\n
In HTML, boolean attributes are usually rendered with no value. Consider the example below where the first button is disabled and the second is not:
<button disabled>Click me!</button> <button>Click me!</button>\n
HTML rendering with
html_attrs
tag orattributes_to_string
works the same way, wherekey=True
is rendered simply askey
, andkey=False
is not render at all.So given this input:
attrs = {\n \"disabled\": True,\n \"autofocus\": False,\n}\n
And template:
<div {% html_attrs attrs %}>\n</div>\n
Then this renders:
"},{"location":"concepts/fundamentals/html_attributes/#default-attributes","title":"Default attributes","text":"<div disabled></div>\n
Sometimes you may want to specify default values for attributes. You can pass a second argument (or kwarg
defaults
) to set the defaults.<div {% html_attrs attrs defaults %}>\n ...\n</div>\n
In the example above, if
attrs
contains e.g. theclass
key,html_attrs
will render:class=\"{{ attrs.class }}\"
Otherwise,
html_attrs
will render:
"},{"location":"concepts/fundamentals/html_attributes/#appending-attributes","title":"Appending attributes","text":"class=\"{{ defaults.class }}\"
For the
class
HTML attribute, it's common that we want to join multiple values, instead of overriding them. For example, if you're authoring a component, you may want to ensure that the component will ALWAYS have a specific class. Yet, you may want to allow users of your component to supply their own classes.We can achieve this by adding extra kwargs. These values will be appended, instead of overwriting the previous value.
So if we have a variable
attrs
:attrs = {\n \"class\": \"my-class pa-4\",\n}\n
And on
html_attrs
tag, we set the keyclass
:<div {% html_attrs attrs class=\"some-class\" %}>\n</div>\n
Then these will be merged and rendered as:
<div data-value=\"my-class pa-4 some-class\"></div>\n
To simplify merging of variables, you can supply the same key multiple times, and these will be all joined together:
{# my_var = \"class-from-var text-red\" #}\n<div {% html_attrs attrs class=\"some-class another-class\" class=my_var %}>\n</div>\n
Renders:
"},{"location":"concepts/fundamentals/html_attributes/#rules-for-html_attrs","title":"Rules for<div\n data-value=\"my-class pa-4 some-class another-class class-from-var text-red\"\n></div>\n
html_attrs
","text":"- Both
attrs
anddefaults
can be passed as positional args
{% html_attrs attrs defaults key=val %}
or as kwargs
{% html_attrs key=val defaults=defaults attrs=attrs %}
-
Both
attrs
anddefaults
are optional (can be omitted) -
Both
attrs
anddefaults
are dictionaries, and we can define them the same way we define dictionaries for thecomponent
tag. So either asattrs=attrs
orattrs:key=value
. -
All other kwargs are appended and can be repeated.
html_attrs
","text":"Assuming that:
class_from_var = \"from-var\"\n\nattrs = {\n \"class\": \"from-attrs\",\n \"type\": \"submit\",\n}\n\ndefaults = {\n \"class\": \"from-defaults\",\n \"role\": \"button\",\n}\n
Then:
- Empty tag
{% html_attr %}
renders (empty string):
- Only kwargs
{% html_attr class=\"some-class\" class=class_from_var data-id=\"123\" %}
renders:
class=\"some-class from-var\" data-id=\"123\"
- Only attrs
{% html_attr attrs %}
renders:
class=\"from-attrs\" type=\"submit\"
- Attrs as kwarg
{% html_attr attrs=attrs %}
renders:
class=\"from-attrs\" type=\"submit\"
- Only defaults (as kwarg)
{% html_attr defaults=defaults %}
renders:
class=\"from-defaults\" role=\"button\"
- Attrs using the
prefix:key=value
construct{% html_attr attrs:class=\"from-attrs\" attrs:type=\"submit\" %}
renders:
class=\"from-attrs\" type=\"submit\"
- Defaults using the
prefix:key=value
construct{% html_attr defaults:class=\"from-defaults\" %}
renders:
class=\"from-defaults\" role=\"button\"
- All together (1) - attrs and defaults as positional args:
{% html_attrs attrs defaults class=\"added_class\" class=class_from_var data-id=123 %}
renders:
class=\"from-attrs added_class from-var\" type=\"submit\" role=\"button\" data-id=123
- All together (2) - attrs and defaults as kwargs args:
{% html_attrs class=\"added_class\" class=class_from_var data-id=123 attrs=attrs defaults=defaults %}
renders:
class=\"from-attrs added_class from-var\" type=\"submit\" role=\"button\" data-id=123
- All together (3) - mixed:
{% html_attrs attrs defaults:class=\"default-class\" class=\"added_class\" class=class_from_var data-id=123 %}
renders:
"},{"location":"concepts/fundamentals/html_attributes/#full-example-for-html_attrs","title":"Full example forclass=\"from-attrs added_class from-var\" type=\"submit\" data-id=123
html_attrs
","text":"@register(\"my_comp\")\nclass MyComp(Component):\n template: t.django_html = \"\"\"\n <div\n {% html_attrs attrs\n defaults:class=\"pa-4 text-red\"\n class=\"my-comp-date\"\n class=class_from_var\n data-id=\"123\"\n %}\n >\n Today's date is <span>{{ date }}</span>\n </div>\n \"\"\"\n\n def get_context_data(self, date: Date, attrs: dict):\n return {\n \"date\": date,\n \"attrs\": attrs,\n \"class_from_var\": \"extra-class\"\n }\n\n@register(\"parent\")\nclass Parent(Component):\n template: t.django_html = \"\"\"\n {% component \"my_comp\"\n date=date\n attrs:class=\"pa-0 border-solid border-red\"\n attrs:data-json=json_data\n attrs:@click=\"(e) => onClick(e, 'from_parent')\"\n / %}\n \"\"\"\n\n def get_context_data(self, date: Date):\n return {\n \"date\": datetime.now(),\n \"json_data\": json.dumps({\"value\": 456})\n }\n
Note: For readability, we've split the tags across multiple lines.
Inside
MyComp
, we defined a default attributedefaults:class=\"pa-4 text-red\"
So if
attrs
includes keyclass
, the default above will be ignored.MyComp
also definesclass
key twice. It means that whether theclass
attribute is taken fromattrs
ordefaults
, the twoclass
values will be appended to it.So by default,
MyComp
renders:<div class=\"pa-4 text-red my-comp-date extra-class\" data-id=\"123\">...</div>\n
Next, let's consider what will be rendered when we call
MyComp
fromParent
component.MyComp
accepts aattrs
dictionary, that is passed tohtml_attrs
, so the contents of that dictionary are rendered as the HTML attributes.In
Parent
, we make use of passing dictionary key-value pairs as kwargs to define individual attributes as if they were regular kwargs.So all kwargs that start with
attrs:
will be collected into anattrs
dict.attrs:class=\"pa-0 border-solid border-red\"\n attrs:data-json=json_data\n attrs:@click=\"(e) => onClick(e, 'from_parent')\"\n
And
get_context_data
ofMyComp
will receiveattrs
input with following keys:attrs = {\n \"class\": \"pa-0 border-solid\",\n \"data-json\": '{\"value\": 456}',\n \"@click\": \"(e) => onClick(e, 'from_parent')\",\n}\n
attrs[\"class\"]
overrides the default value forclass
, whereas other keys will be merged.So in the end
MyComp
will render:
"},{"location":"concepts/fundamentals/html_attributes/#rendering-html-attributes-outside-of-templates","title":"Rendering HTML attributes outside of templates","text":"<div\n class=\"pa-0 border-solid my-comp-date extra-class\"\n data-id=\"123\"\n data-json='{\"value\": 456}'\n @click=\"(e) => onClick(e, 'from_parent')\"\n>\n ...\n</div>\n
If you need to use serialize HTML attributes outside of Django template and the
html_attrs
tag, you can useattributes_to_string
:
"},{"location":"concepts/fundamentals/single_file_components/","title":"Single-file components","text":"from django_components.attributes import attributes_to_string\n\nattrs = {\n \"class\": \"my-class text-red pa-4\",\n \"data-id\": 123,\n \"required\": True,\n \"disabled\": False,\n \"ignored-attr\": None,\n}\n\nattributes_to_string(attrs)\n# 'class=\"my-class text-red pa-4\" data-id=\"123\" required'\n
Components can be defined in a single file, which is useful for small components. To do this, you can use the
template
,js
, andcss
class attributes instead of thetemplate_file
,js_file
, andcss_file
.For example, here's the calendar component from the Getting started tutorial, defined in a single file:
[project root]/components/calendar.pyfrom django_components import Component, register, types\n\n@register(\"calendar\")\nclass Calendar(Component):\n def get_context_data(self, date):\n return {\n \"date\": date,\n }\n\n template: types.django_html = \"\"\"\n <div class=\"calendar\">\n Today's date is <span>{{ date }}</span>\n </div>\n \"\"\"\n\n css: types.css = \"\"\"\n .calendar {\n width: 200px;\n background: pink;\n }\n .calendar span {\n font-weight: bold;\n }\n \"\"\"\n\n js: types.js = \"\"\"\n (function(){\n if (document.querySelector(\".calendar\")) {\n document.querySelector(\".calendar\").onclick = () => {\n alert(\"Clicked calendar!\");\n };\n }\n })()\n \"\"\"\n
This makes it easy to create small components without having to create a separate template, CSS, and JS file.
To add syntax highlighting to these snippets, head over to Syntax highlighting.
"},{"location":"concepts/fundamentals/slots/","title":"Slots","text":"New in version 0.26:
- The
slot
tag now serves only to declare new slots inside the component template. - To override the content of a declared slot, use the newly introduced
fill
tag instead. - Whereas unfilled slots used to raise a warning, filling a slot is now optional by default.
- To indicate that a slot must be filled, the new
required
option should be added at the end of theslot
tag.
Components support something called 'slots'. When a component is used inside another template, slots allow the parent template to override specific parts of the child component by passing in different content. This mechanism makes components more reusable and composable. This behavior is similar to slots in Vue.
In the example below we introduce two block tags that work hand in hand to make this work. These are...
{% slot <name> %}
/{% endslot %}
: Declares a new slot in the component template.{% fill <name> %}
/{% endfill %}
: (Used inside a{% component %}
tag pair.) Fills a declared slot with the specified content.
Let's update our calendar component to support more customization. We'll add
slot
tag pairs to its template, template.html.<div class=\"calendar-component\">\n <div class=\"header\">\n {% slot \"header\" %}Calendar header{% endslot %}\n </div>\n <div class=\"body\">\n {% slot \"body\" %}Today's date is <span>{{ date }}</span>{% endslot %}\n </div>\n</div>\n
When using the component, you specify which slots you want to fill and where you want to use the defaults from the template. It looks like this:
{% component \"calendar\" date=\"2020-06-06\" %}\n {% fill \"body\" %}\n Can you believe it's already <span>{{ date }}</span>??\n {% endfill %}\n{% endcomponent %}\n
Since the 'header' fill is unspecified, it's taken from the base template. If you put this in a template, and pass in
date=2020-06-06
, this is what gets rendered:
"},{"location":"concepts/fundamentals/slots/#named-slots","title":"Named slots","text":"<div class=\"calendar-component\">\n <div class=\"header\">\n Calendar header\n </div>\n <div class=\"body\">\n Can you believe it's already <span>2020-06-06</span>??\n </div>\n</div>\n
As seen in the previouse section, you can use
{% fill slot_name %}
to insert content into a specific slot.You can define fills for multiple slot simply by defining them all within the
{% component %} {% endcomponent %}
tags:{% component \"calendar\" date=\"2020-06-06\" %}\n {% fill \"header\" %}\n Hi this is header!\n {% endfill %}\n {% fill \"body\" %}\n Can you believe it's already <span>{{ date }}</span>??\n {% endfill %}\n{% endcomponent %}\n
You can also use
{% for %}
,{% with %}
, or other non-component tags (even{% include %}
) to construct the{% fill %}
tags, as long as these other tags do not leave any text behind!
"},{"location":"concepts/fundamentals/slots/#default-slot","title":"Default slot","text":"{% component \"table\" %}\n {% for slot_name in slots %}\n {% fill name=slot_name %}\n {{ slot_name }}\n {% endfill %}\n {% endfor %}\n\n {% with slot_name=\"abc\" %}\n {% fill name=slot_name %}\n {{ slot_name }}\n {% endfill %}\n {% endwith %}\n{% endcomponent %}\n
Added in version 0.28
As you can see, component slots lets you write reusable containers that you fill in when you use a component. This makes for highly reusable components that can be used in different circumstances.
It can become tedious to use
fill
tags everywhere, especially when you're using a component that declares only one slot. To make things easier,slot
tags can be marked with an optional keyword:default
.When added to the tag (as shown below), this option lets you pass filling content directly in the body of a
component
tag pair \u2013 without using afill
tag. Choose carefully, though: a component template may contain at most one slot that is marked asdefault
. Thedefault
option can be combined with other slot options, e.g.required
.Here's the same example as before, except with default slots and implicit filling.
The template:
<div class=\"calendar-component\">\n <div class=\"header\">\n {% slot \"header\" %}Calendar header{% endslot %}\n </div>\n <div class=\"body\">\n {% slot \"body\" default %}Today's date is <span>{{ date }}</span>{% endslot %}\n </div>\n</div>\n
Including the component (notice how the
fill
tag is omitted):{% component \"calendar\" date=\"2020-06-06\" %}\n Can you believe it's already <span>{{ date }}</span>??\n{% endcomponent %}\n
The rendered result (exactly the same as before):
<div class=\"calendar-component\">\n <div class=\"header\">Calendar header</div>\n <div class=\"body\">Can you believe it's already <span>2020-06-06</span>??</div>\n</div>\n
You may be tempted to combine implicit fills with explicit
fill
tags. This will not work. The following component template will raise an error when rendered.{# DON'T DO THIS #}\n{% component \"calendar\" date=\"2020-06-06\" %}\n {% fill \"header\" %}Totally new header!{% endfill %}\n Can you believe it's already <span>{{ date }}</span>??\n{% endcomponent %}\n
Instead, you can use a named fill with name
default
to target the default fill:{# THIS WORKS #}\n{% component \"calendar\" date=\"2020-06-06\" %}\n {% fill \"header\" %}Totally new header!{% endfill %}\n {% fill \"default\" %}\n Can you believe it's already <span>{{ date }}</span>??\n {% endfill %}\n{% endcomponent %}\n
NOTE: If you doubly-fill a slot, that is, that both
"},{"location":"concepts/fundamentals/slots/#accessing-default-slot-in-python","title":"Accessing default slot in Python","text":"{% fill \"default\" %}
and{% fill \"header\" %}
would point to the same slot, this will raise an error when rendered.Since the default slot is stored under the slot name
default
, you can access the default slot like so:
"},{"location":"concepts/fundamentals/slots/#render-fill-in-multiple-places","title":"Render fill in multiple places","text":"class MyTable(Component):\n def get_context_data(self, *args, **kwargs):\n default_slot = self.input.slots[\"default\"]\n return {\n \"default_slot\": default_slot,\n }\n
Added in version 0.70
You can render the same content in multiple places by defining multiple slots with identical names:
<div class=\"calendar-component\">\n <div class=\"header\">\n {% slot \"image\" %}Image here{% endslot %}\n </div>\n <div class=\"body\">\n {% slot \"image\" %}Image here{% endslot %}\n </div>\n</div>\n
So if used like:
{% component \"calendar\" date=\"2020-06-06\" %}\n {% fill \"image\" %}\n <img src=\"...\" />\n {% endfill %}\n{% endcomponent %}\n
This renders:
"},{"location":"concepts/fundamentals/slots/#default-and-required-slots","title":"Default and required slots","text":"<div class=\"calendar-component\">\n <div class=\"header\">\n <img src=\"...\" />\n </div>\n <div class=\"body\">\n <img src=\"...\" />\n </div>\n</div>\n
If you use a slot multiple times, you can still mark the slot as
default
orrequired
. For that, you must mark each slot individually, e.g.:<div class=\"calendar-component\">\n <div class=\"header\">\n {% slot \"image\" default required %}Image here{% endslot %}\n </div>\n <div class=\"body\">\n {% slot \"image\" default required %}Image here{% endslot %}\n </div>\n</div>\n
Which you can then use as regular default slot:
{% component \"calendar\" date=\"2020-06-06\" %}\n <img src=\"...\" />\n{% endcomponent %}\n
Since each slot is tagged individually, you can have multiple slots with the same name but different conditions.
E.g. in this example, we have a component that renders a user avatar - a small circular image with a profile picture or name initials.
If the component is given
image_src
orname_initials
variables, theimage
slot is optional. But if neither of those are provided, you MUST fill theimage
slot.
"},{"location":"concepts/fundamentals/slots/#accessing-original-content-of-slots","title":"Accessing original content of slots","text":"<div class=\"avatar\">\n {% if image_src %}\n {% slot \"image\" default %}\n <img src=\"{{ image_src }}\" />\n {% endslot %}\n {% elif name_initials %}\n {% slot \"image\" default %}\n <div style=\"\n border-radius: 25px;\n width: 50px;\n height: 50px;\n background: blue;\n \">\n {{ name_initials }}\n </div>\n {% endslot %}\n {% else %}\n {% slot \"image\" default required / %}\n {% endif %}\n</div>\n
Added in version 0.26
NOTE: In version 0.77, the syntax was changed from
{% fill \"my_slot\" as \"alias\" %} {{ alias.default }}\n
to
{% fill \"my_slot\" default=\"slot_default\" %} {{ slot_default }}\n
Sometimes you may want to keep the original slot, but only wrap or prepend/append content to it. To do so, you can access the default slot via the
default
kwarg.Similarly to the
data
attribute, you specify the variable name through which the default slot will be made available.For instance, let's say you're filling a slot called 'body'. To render the original slot, assign it to a variable using the
'default'
keyword. You then render this variable to insert the default content:{% component \"calendar\" date=\"2020-06-06\" %}\n {% fill \"body\" default=\"body_default\" %}\n {{ body_default }}. Have a great day!\n {% endfill %}\n{% endcomponent %}\n
This produces:
<div class=\"calendar-component\">\n <div class=\"header\">\n Calendar header\n </div>\n <div class=\"body\">\n Today's date is <span>2020-06-06</span>. Have a great day!\n </div>\n</div>\n
To access the original content of a default slot, set the name to
default
:
"},{"location":"concepts/fundamentals/slots/#conditional-slots","title":"Conditional slots","text":"{% component \"calendar\" date=\"2020-06-06\" %}\n {% fill \"default\" default=\"slot_default\" %}\n {{ slot_default }}. Have a great day!\n {% endfill %}\n{% endcomponent %}\n
Added in version 0.26.
NOTE: In version 0.70,
{% if_filled %}
tags were replaced with{{ component_vars.is_filled }}
variables. If your slot name contained special characters, see the section Accessingis_filled
of slot names with special characters.In certain circumstances, you may want the behavior of slot filling to depend on whether or not a particular slot is filled.
For example, suppose we have the following component template:
<div class=\"frontmatter-component\">\n <div class=\"title\">\n {% slot \"title\" %}Title{% endslot %}\n </div>\n <div class=\"subtitle\">\n {% slot \"subtitle\" %}{# Optional subtitle #}{% endslot %}\n </div>\n</div>\n
By default the slot named 'subtitle' is empty. Yet when the component is used without explicit fills, the div containing the slot is still rendered, as shown below:
<div class=\"frontmatter-component\">\n <div class=\"title\">Title</div>\n <div class=\"subtitle\"></div>\n</div>\n
This may not be what you want. What if instead the outer 'subtitle' div should only be included when the inner slot is in fact filled?
The answer is to use the
{{ component_vars.is_filled.<name> }}
variable. You can use this together with Django's{% if/elif/else/endif %}
tags to define a block whose contents will be rendered only if the component slot with the corresponding 'name' is filled.This is what our example looks like with
component_vars.is_filled
.<div class=\"frontmatter-component\">\n <div class=\"title\">\n {% slot \"title\" %}Title{% endslot %}\n </div>\n {% if component_vars.is_filled.subtitle %}\n <div class=\"subtitle\">\n {% slot \"subtitle\" %}{# Optional subtitle #}{% endslot %}\n </div>\n {% endif %}\n</div>\n
Here's our example with more complex branching.
<div class=\"frontmatter-component\">\n <div class=\"title\">\n {% slot \"title\" %}Title{% endslot %}\n </div>\n {% if component_vars.is_filled.subtitle %}\n <div class=\"subtitle\">\n {% slot \"subtitle\" %}{# Optional subtitle #}{% endslot %}\n </div>\n {% elif component_vars.is_filled.title %}\n ...\n {% elif component_vars.is_filled.<name> %}\n ...\n {% endif %}\n</div>\n
Sometimes you're not interested in whether a slot is filled, but rather that it isn't. To negate the meaning of
component_vars.is_filled
, simply treat it as boolean and negate it withnot
:
"},{"location":"concepts/fundamentals/slots/#accessing-is_filled-of-slot-names-with-special-characters","title":"Accessing{% if not component_vars.is_filled.subtitle %}\n<div class=\"subtitle\">\n {% slot \"subtitle\" / %}\n</div>\n{% endif %}\n
is_filled
of slot names with special characters","text":"To be able to access a slot name via
component_vars.is_filled
, the slot name needs to be composed of only alphanumeric characters and underscores (e.g.this__isvalid_123
).However, you can still define slots with other special characters. In such case, the slot name in
component_vars.is_filled
is modified to replace all invalid characters into_
.So a slot named
\"my super-slot :)\"
will be available ascomponent_vars.is_filled.my_super_slot___
.Same applies when you are accessing
is_filled
from within the Python, e.g.:
"},{"location":"concepts/fundamentals/slots/#conditional-fills","title":"Conditional fills","text":"class MyTable(Component):\n def on_render_before(self, context, template) -> None:\n # \u2705 Works\n if self.is_filled[\"my_super_slot___\"]:\n # Do something\n\n # \u274c Does not work\n if self.is_filled[\"my super-slot :)\"]:\n # Do something\n
Similarly, you can use
{% if %}
and{% for %}
when defining the{% fill %}
tags, to conditionally fill the slots when using the componnet:In the example below, the
{% fill \"footer\" %}
fill is used only if the condition is true. If falsy, the fill is ignored, and so themy_table
component will use its default content for thefooter
slot.{% component \"my_table\" %}\n {% if editable %}\n {% fill \"footer\" %}\n <input name=\"name\" />\n {% endfill %}\n {% endif %}\n{% endcomponent %}\n
You can even combine
{% if %}
and{% for %}
:
"},{"location":"concepts/fundamentals/slots/#scoped-slots","title":"Scoped slots","text":"{% component \"my_table\" %}\n {% for header in headers %}\n {% if header != \"hyperlink\" %}\n {# Generate fill name like `header.my_column` #}\n {% fill name=\"header.\"|add:header\" %}\n <b>{{ header }}</b>\n {% endfill %}\n {% endif %}\n {% endfor %}\n{% endcomponent %}\n
Added in version 0.76:
Consider a component with slot(s). This component may do some processing on the inputs, and then use the processed variable in the slot's default template:
@register(\"my_comp\")\nclass MyComp(Component):\n template = \"\"\"\n <div>\n {% slot \"content\" default %}\n input: {{ input }}\n {% endslot %}\n </div>\n \"\"\"\n\n def get_context_data(self, input):\n processed_input = do_something(input)\n return {\"input\": processed_input}\n
You may want to design a component so that users of your component can still access the
input
variable, so they don't have to recompute it.This behavior is called \"scoped slots\". This is inspired by Vue scoped slots and scoped slots of django-web-components.
Using scoped slots consists of two steps:
- Passing data to
slot
tag - Accessing data in
fill
tag
To pass the data to the
slot
tag, simply pass them as keyword attributes (key=value
):
"},{"location":"concepts/fundamentals/slots/#accessing-slot-data-in-fill","title":"Accessing slot data in fill","text":"@register(\"my_comp\")\nclass MyComp(Component):\n template = \"\"\"\n <div>\n {% slot \"content\" default input=input %}\n input: {{ input }}\n {% endslot %}\n </div>\n \"\"\"\n\n def get_context_data(self, input):\n processed_input = do_something(input)\n return {\n \"input\": processed_input,\n }\n
Next, we head over to where we define a fill for this slot. Here, to access the slot data we set the
data
attribute to the name of the variable through which we want to access the slot data. In the example below, we set it todata
:{% component \"my_comp\" %}\n {% fill \"content\" data=\"slot_data\" %}\n {{ slot_data.input }}\n {% endfill %}\n{% endcomponent %}\n
To access slot data on a default slot, you have to explictly define the
{% fill %}
tags.So this works:
{% component \"my_comp\" %}\n {% fill \"content\" data=\"slot_data\" %}\n {{ slot_data.input }}\n {% endfill %}\n{% endcomponent %}\n
While this does not:
{% component \"my_comp\" data=\"data\" %}\n {{ data.input }}\n{% endcomponent %}\n
Note: You cannot set the
data
attribute anddefault
attribute) to the same name. This raises an error:
"},{"location":"concepts/fundamentals/slots/#slot-data-of-default-slots","title":"Slot data of default slots","text":"{% component \"my_comp\" %}\n {% fill \"content\" data=\"slot_var\" default=\"slot_var\" %}\n {{ slot_var.input }}\n {% endfill %}\n{% endcomponent %}\n
To access data of a default slot, you can specify
{% fill name=\"default\" %}
:
"},{"location":"concepts/fundamentals/slots/#dynamic-slots-and-fills","title":"Dynamic slots and fills","text":"{% component \"my_comp\" %}\n {% fill \"default\" data=\"slot_data\" %}\n {{ slot_data.input }}\n {% endfill %}\n{% endcomponent %}\n
Until now, we were declaring slot and fill names statically, as a string literal, e.g.
{% slot \"content\" / %}\n
However, sometimes you may want to generate slots based on the given input. One example of this is a table component like that of Vuetify, which creates a header and an item slots for each user-defined column.
In django_components you can achieve the same, simply by using a variable (or a template expression) instead of a string literal:
<table>\n <tr>\n {% for header in headers %}\n <th>\n {% slot \"header-{{ header.key }}\" value=header.title %}\n {{ header.title }}\n {% endslot %}\n </th>\n {% endfor %}\n </tr>\n</table>\n
When using the component, you can either set the fill explicitly:
{% component \"table\" headers=headers items=items %}\n {% fill \"header-name\" data=\"data\" %}\n <b>{{ data.value }}</b>\n {% endfill %}\n{% endcomponent %}\n
Or also use a variable:
{% component \"table\" headers=headers items=items %}\n {# Make only the active column bold #}\n {% fill \"header-{{ active_header_name }}\" data=\"data\" %}\n <b>{{ data.value }}</b>\n {% endfill %}\n{% endcomponent %}\n
NOTE: It's better to use static slot names whenever possible for clarity. The dynamic slot names should be reserved for advanced use only.
Lastly, in rare cases, you can also pass the slot name via the spread operator. This is possible, because the slot name argument is actually a shortcut for a
name
keyword argument.So this:
{% slot \"content\" / %}\n
is the same as:
{% slot name=\"content\" / %}\n
So it's possible to define a
name
key on a dictionary, and then spread that onto the slot tag:
"},{"location":"concepts/fundamentals/slots/#pass-through-all-the-slots","title":"Pass through all the slots","text":"{# slot_props = {\"name\": \"content\"} #}\n{% slot ...slot_props / %}\n
You can dynamically pass all slots to a child component. This is similar to passing all slots in Vue:
"},{"location":"concepts/fundamentals/subclassing_components/","title":"Subclassing components","text":"class MyTable(Component):\n def get_context_data(self, *args, **kwargs):\n return {\n \"slots\": self.input.slots,\n }\n\n template: \"\"\"\n <div>\n {% component \"child\" %}\n {% for slot_name in slots %}\n {% fill name=slot_name data=\"data\" %}\n {% slot name=slot_name ...data / %}\n {% endfill %}\n {% endfor %}\n {% endcomponent %}\n </div>\n \"\"\"\n
In larger projects, you might need to write multiple components with similar behavior. In such cases, you can extract shared behavior into a standalone component class to keep things DRY.
When subclassing a component, there's a couple of things to keep in mind:
"},{"location":"concepts/fundamentals/subclassing_components/#template-js-and-css-inheritance","title":"Template, JS, and CSS Inheritance","text":"When it comes to the pairs:
Component.template
/Component.template_file
Component.js
/Component.js_file
Component.css
/Component.css_file
inheritance follows these rules:
- If a child component class defines either member of a pair (e.g., either
template
ortemplate_file
), it takes precedence and the parent's definition is ignored completely. - For example, if a child component defines
template_file
, the parent'stemplate
ortemplate_file
will be ignored. - This applies independently to each pair - you can inherit the JS while overriding the template, for instance.
For example:
"},{"location":"concepts/fundamentals/subclassing_components/#media-class-inheritance","title":"Media Class Inheritance","text":"class BaseCard(Component):\n template = \"\"\"\n <div class=\"card\">\n <div class=\"card-content\">{{ content }}</div>\n </div>\n \"\"\"\n css = \"\"\"\n .card {\n border: 1px solid gray;\n }\n \"\"\"\n js = \"console.log('Base card loaded');\"\n\n# This class overrides parent's template, but inherits CSS and JS\nclass SpecialCard(BaseCard):\n template = \"\"\"\n <div class=\"card special\">\n <div class=\"card-content\">\u2728 {{ content }} \u2728</div>\n </div>\n \"\"\"\n\n# This class overrides parent's template and CSS, but inherits JS\nclass CustomCard(BaseCard):\n template_file = \"custom_card.html\"\n css = \"\"\"\n .card {\n border: 2px solid gold;\n }\n \"\"\"\n
The
Component.Media
nested class follows Django's media inheritance rules:- If both parent and child define a
Media
class, the child's media will automatically include both its own and the parent's JS and CSS files. - This behavior can be configured using the
extend
attribute in the Media class, similar to Django's forms. Read more on this in Controlling Media Inheritance.
For example:
"},{"location":"concepts/fundamentals/subclassing_components/#regular-python-inheritance","title":"Regular Python Inheritance","text":"class BaseModal(Component):\n template = \"<div>Modal content</div>\"\n\n class Media:\n css = [\"base_modal.css\"]\n js = [\"base_modal.js\"] # Contains core modal functionality\n\nclass FancyModal(BaseModal):\n class Media:\n # Will include both base_modal.css/js AND fancy_modal.css/js\n css = [\"fancy_modal.css\"] # Additional styling\n js = [\"fancy_modal.js\"] # Additional animations\n\nclass SimpleModal(BaseModal):\n class Media:\n extend = False # Don't inherit parent's media\n css = [\"simple_modal.css\"] # Only this CSS will be included\n js = [\"simple_modal.js\"] # Only this JS will be included\n
All other attributes and methods (including the
Component.View
class and its methods) follow standard Python inheritance rules.For example:
"},{"location":"concepts/fundamentals/template_tag_syntax/","title":"Template tag syntax","text":"class BaseForm(Component):\n template = \"\"\"\n <form>\n {{ form_content }}\n <button type=\"submit\">\n {{ submit_text }}\n </button>\n </form>\n \"\"\"\n\n def get_context_data(self, **kwargs):\n return {\n \"form_content\": self.get_form_content(),\n \"submit_text\": \"Submit\"\n }\n\n def get_form_content(self):\n return \"<input type='text' name='data'>\"\n\nclass ContactForm(BaseForm):\n # Extend parent's \"context\"\n # but override \"submit_text\"\n def get_context_data(self, **kwargs):\n context = super().get_context_data(**kwargs)\n context[\"submit_text\"] = \"Send Message\" \n return context\n\n # Completely override parent's get_form_content\n def get_form_content(self):\n return \"\"\"\n <input type='text' name='name' placeholder='Your Name'>\n <input type='email' name='email' placeholder='Your Email'>\n <textarea name='message' placeholder='Your Message'></textarea>\n \"\"\"\n
All template tags in django_component, like
"},{"location":"concepts/fundamentals/template_tag_syntax/#self-closing-tags","title":"Self-closing tags","text":"{% component %}
or{% slot %}
, and so on, support extra syntax that makes it possible to write components like in Vue or React (JSX).When you have a tag like
{% component %}
or{% slot %}
, but it has no content, you can simply append a forward slash/
at the end, instead of writing out the closing tags like{% endcomponent %}
or{% endslot %}
:So this:
{% component \"button\" %}{% endcomponent %}\n
becomes
"},{"location":"concepts/fundamentals/template_tag_syntax/#special-characters","title":"Special characters","text":"{% component \"button\" / %}\n
New in version 0.71:
Keyword arguments can contain special characters
# @ . - _
, so keywords like so are still valid:<body>\n {% component \"calendar\" my-date=\"2015-06-19\" @click.native=do_something #some_id=True / %}\n</body>\n
These can then be accessed inside
get_context_data
so:
"},{"location":"concepts/fundamentals/template_tag_syntax/#spread-operator","title":"Spread operator","text":"@register(\"calendar\")\nclass Calendar(Component):\n # Since # . @ - are not valid identifiers, we have to\n # use `**kwargs` so the method can accept these args.\n def get_context_data(self, **kwargs):\n return {\n \"date\": kwargs[\"my-date\"],\n \"id\": kwargs[\"#some_id\"],\n \"on_click\": kwargs[\"@click.native\"]\n }\n
New in version 0.93:
Instead of passing keyword arguments one-by-one:
{% component \"calendar\" title=\"How to abc\" date=\"2015-06-19\" author=\"John Wick\" / %}\n
You can use a spread operator
...dict
to apply key-value pairs from a dictionary:post_data = {\n \"title\": \"How to...\",\n \"date\": \"2015-06-19\",\n \"author\": \"John Wick\",\n}\n
{% component \"calendar\" ...post_data / %}\n
This behaves similar to JSX's spread operator or Vue's
v-bind
.Spread operators are treated as keyword arguments, which means that:
- Spread operators must come after positional arguments.
- You cannot use spread operators for positional-only arguments.
Other than that, you can use spread operators multiple times, and even put keyword arguments in-between or after them:
{% component \"calendar\" ...post_data id=post.id ...extra / %}\n
In a case of conflicts, the values added later (right-most) overwrite previous values.
"},{"location":"concepts/fundamentals/template_tag_syntax/#use-template-tags-inside-component-inputs","title":"Use template tags inside component inputs","text":"New in version 0.93
When passing data around, sometimes you may need to do light transformations, like negating booleans or filtering lists.
Normally, what you would have to do is to define ALL the variables inside
get_context_data()
. But this can get messy if your components contain a lot of logic.@register(\"calendar\")\nclass Calendar(Component):\n def get_context_data(self, id: str, editable: bool):\n return {\n \"editable\": editable,\n \"readonly\": not editable,\n \"input_id\": f\"input-{id}\",\n \"icon_id\": f\"icon-{id}\",\n ...\n }\n
Instead, template tags in django_components (
{% component %}
,{% slot %}
,{% provide %}
, etc) allow you to treat literal string values as templates:{% component 'blog_post'\n \"As positional arg {# yay #}\"\n title=\"{{ person.first_name }} {{ person.last_name }}\"\n id=\"{% random_int 10 20 %}\"\n readonly=\"{{ editable|not }}\"\n author=\"John Wick {# TODO: parametrize #}\"\n/ %}\n
In the example above:
- Component
test
receives a positional argument with value\"As positional arg \"
. The comment is omitted. - Kwarg
title
is passed as a string, e.g.John Doe
- Kwarg
id
is passed asint
, e.g.15
- Kwarg
readonly
is passed asbool
, e.g.False
- Kwarg
author
is passed as a string, e.g.John Wick
(Comment omitted)
This is inspired by django-cotton.
"},{"location":"concepts/fundamentals/template_tag_syntax/#passing-data-as-string-vs-original-values","title":"Passing data as string vs original values","text":"Sometimes you may want to use the template tags to transform or generate the data that is then passed to the component.
The data doesn't necessarily have to be strings. In the example above, the kwarg
id
was passed as an integer, NOT a string.Although the string literals for components inputs are treated as regular Django templates, there is one special case:
When the string literal contains only a single template tag, with no extra text, then the value is passed as the original type instead of a string.
Here,
page
is an integer:{% component 'blog_post' page=\"{% random_int 10 20 %}\" / %}\n
Here,
page
is a string:{% component 'blog_post' page=\" {% random_int 10 20 %} \" / %}\n
And same applies to the
{{ }}
variable tags:Here,
items
is a list:{% component 'cat_list' items=\"{{ cats|slice:':2' }}\" / %}\n
Here,
items
is a string:
"},{"location":"concepts/fundamentals/template_tag_syntax/#evaluating-python-expressions-in-template","title":"Evaluating Python expressions in template","text":"{% component 'cat_list' items=\"{{ cats|slice:':2' }} See more\" / %}\n
You can even go a step further and have a similar experience to Vue or React, where you can evaluate arbitrary code expressions:
<MyForm value={isEnabled ? inputValue : null} />\n
Similar is possible with
django-expr
, which adds anexpr
tag and filter that you can use to evaluate Python expressions from within the template:{% component \"my_form\"\n value=\"{% expr 'input_value if is_enabled else None' %}\"\n/ %}\n
Note: Never use this feature to mix business logic and template logic. Business logic should still be in the view!
"},{"location":"concepts/fundamentals/template_tag_syntax/#pass-dictonary-by-its-key-value-pairs","title":"Pass dictonary by its key-value pairs","text":"New in version 0.74:
Sometimes, a component may expect a dictionary as one of its inputs.
Most commonly, this happens when a component accepts a dictionary of HTML attributes (usually called
attrs
) to pass to the underlying template.In such cases, we may want to define some HTML attributes statically, and other dynamically. But for that, we need to define this dictionary on Python side:
@register(\"my_comp\")\nclass MyComp(Component):\n template = \"\"\"\n {% component \"other\" attrs=attrs / %}\n \"\"\"\n\n def get_context_data(self, some_id: str):\n attrs = {\n \"class\": \"pa-4 flex\",\n \"data-some-id\": some_id,\n \"@click.stop\": \"onClickHandler\",\n }\n return {\"attrs\": attrs}\n
But as you can see in the case above, the event handler
@click.stop
and stylingpa-4 flex
are disconnected from the template. If the component grew in size and we moved the HTML to a separate file, we would have hard time reasoning about the component's template.Luckily, there's a better way.
When we want to pass a dictionary to a component, we can define individual key-value pairs as component kwargs, so we can keep all the relevant information in the template. For that, we prefix the key with the name of the dict and
:
. So keyclass
of inputattrs
becomesattrs:class
. And our example becomes:@register(\"my_comp\")\nclass MyComp(Component):\n template = \"\"\"\n {% component \"other\"\n attrs:class=\"pa-4 flex\"\n attrs:data-some-id=some_id\n attrs:@click.stop=\"onClickHandler\"\n / %}\n \"\"\"\n\n def get_context_data(self, some_id: str):\n return {\"some_id\": some_id}\n
Sweet! Now all the relevant HTML is inside the template, and we can move it to a separate file with confidence:
{% component \"other\"\n attrs:class=\"pa-4 flex\"\n attrs:data-some-id=some_id\n attrs:@click.stop=\"onClickHandler\"\n/ %}\n
Note: It is NOT possible to define nested dictionaries, so
attrs:my_key:two=2
would be interpreted as:
"},{"location":"concepts/fundamentals/template_tag_syntax/#multiline-tags","title":"Multiline tags","text":"{\"attrs\": {\"my_key:two\": 2}}\n
By default, Django expects a template tag to be defined on a single line.
However, this can become unwieldy if you have a component with a lot of inputs:
{% component \"card\" title=\"Joanne Arc\" subtitle=\"Head of Kitty Relations\" date_last_active=\"2024-09-03\" ... %}\n
Instead, when you install django_components, it automatically configures Django to suport multi-line tags.
So we can rewrite the above as:
{% component \"card\"\n title=\"Joanne Arc\"\n subtitle=\"Head of Kitty Relations\"\n date_last_active=\"2024-09-03\"\n ...\n%}\n
Much better!
To disable this behavior, set
"},{"location":"getting_started/adding_js_and_css/","title":"Adding JS and CSS","text":"COMPONENTS.multiline_tag
toFalse
Next we will add CSS and JavaScript to our template.
Info
In django-components, using JS and CSS is as simple as defining them on the Component class. You don't have to insert the
<script>
and<link>
tags into the HTML manually.Behind the scenes, django-components keeps track of which components use which JS and CSS files. Thus, when a component is rendered on the page, the page will contain only the JS and CSS used by the components, and nothing more!
"},{"location":"getting_started/adding_js_and_css/#1-update-project-structure","title":"1. Update project structure","text":"Start by creating empty
calendar.js
andcalendar.css
files:
"},{"location":"getting_started/adding_js_and_css/#2-write-css","title":"2. Write CSS","text":"sampleproject/\n\u251c\u2500\u2500 calendarapp/\n\u251c\u2500\u2500 components/\n\u2502 \u2514\u2500\u2500 calendar/\n\u2502 \u251c\u2500\u2500 calendar.py\n\u2502 \u251c\u2500\u2500 calendar.js \ud83c\udd95\n\u2502 \u251c\u2500\u2500 calendar.css \ud83c\udd95\n\u2502 \u2514\u2500\u2500 calendar.html\n\u251c\u2500\u2500 sampleproject/\n\u251c\u2500\u2500 manage.py\n\u2514\u2500\u2500 requirements.txt\n
Inside
[project root]/components/calendar/calendar.csscalendar.css
, write:.calendar {\n width: 200px;\n background: pink;\n}\n.calendar span {\n font-weight: bold;\n}\n
Be sure to prefix your rules with unique CSS class like
calendar
, so the CSS doesn't clash with other rules.Note
Soon, django-components will automatically scope your CSS by default, so you won't have to worry about CSS class clashes.
This CSS will be inserted into the page as an inlined
<style>
tag, at the position defined by{% component_css_dependencies %}
, or at the end of the inside the<head>
tag (See JS and CSS output locations).So in your HTML, you may see something like this:
"},{"location":"getting_started/adding_js_and_css/#3-write-js","title":"3. Write JS","text":"<html>\n <head>\n ...\n <style>\n .calendar {\n width: 200px;\n background: pink;\n }\n .calendar span {\n font-weight: bold;\n }\n </style>\n </head>\n <body>\n ...\n </body>\n</html>\n
Next we write a JavaScript file that specifies how to interact with this component.
You are free to use any javascript framework you want.
[project root]/components/calendar/calendar.js(function () {\n document.querySelector(\".calendar\").onclick = () => {\n alert(\"Clicked calendar!\");\n };\n})();\n
A good way to make sure the JS of this component doesn't clash with other components is to define all JS code inside an anonymous self-invoking function (
(() => { ... })()
). This makes all variables defined only be defined inside this component and not affect other components.Note
Soon, django-components will automatically wrap your JS in a self-invoking function by default (except for JS defined with
<script type=\"module\">
).Similarly to CSS, JS will be inserted into the page as an inlined
<script>
tag, at the position defined by{% component_js_dependencies %}
, or at the end of the inside the<body>
tag (See JS and CSS output locations).So in your HTML, you may see something like this:
"},{"location":"getting_started/adding_js_and_css/#rules-of-js-execution","title":"Rules of JS execution","text":"<html>\n <head>\n ...\n </head>\n <body>\n ...\n <script>\n (function () {\n document.querySelector(\".calendar\").onclick = () => {\n alert(\"Clicked calendar!\");\n };\n })();\n </script>\n </body>\n</html>\n
-
JS is executed in the order in which the components are found in the HTML
By default, the JS is inserted as a synchronous script (
<script> ... </script>
)So if you define multiple components on the same page, their JS will be executed in the order in which the components are found in the HTML.
So if we have a template like so:
<html>\n <head>\n ...\n </head>\n <body>\n {% component \"calendar\" / %}\n {% component \"table\" / %}\n </body>\n</html>\n
Then the JS file of the component
calendar
will be executed first, and the JS file of componenttable
will be executed second. -
JS will be executed only once, even if there is multiple instances of the same component
In this case, the JS of
calendar
will STILL execute first (because it was found first), and will STILL execute only once, even though it's present twice:<html>\n <head>\n ...\n </head>\n <body>\n {% component \"calendar\" / %}\n {% component \"table\" / %}\n {% component \"calendar\" / %}\n </body>\n</html>\n
Finally, we return to our Python component in
calendar.py
to tie this together.To link JS and CSS defined in other files, use
[project root]/components/calendar/calendar.pyjs_file
andcss_file
attributes:from django_components import Component\n\nclass Calendar(Component):\n template_file = \"calendar.html\"\n js_file = \"calendar.js\" # <--- new\n css_file = \"calendar.css\" # <--- new\n\n def get_context_data(self):\n return {\n \"date\": \"1970-01-01\",\n }\n
And that's it! If you were to embed this component in an HTML, django-components will automatically embed the associated JS and CSS.
Note
Similarly to the template file, the JS and CSS file paths can be either:
- Relative to the Python component file (as seen above),
- Relative to any of the component directories as defined by
COMPONENTS.dirs
and/orCOMPONENTS.app_dirs
(e.g.[your apps]/components
dir and[project root]/components
) - Relative to any of the directories defined by
STATICFILES_DIRS
.
Your components may depend on third-party packages or styling, or other shared logic. To load these additional dependencies, you can use a nested
Media
class.This
Media
class behaves similarly to Django's Media class, with a few differences:- Our Media class accepts various formats for the JS and CSS files: either a single file, a list, or (CSS-only) a dictonary (see below).
- Individual JS / CSS files can be any of
str
,bytes
,Path
,SafeString
, or a function. - If you set
Media.extend
to a list, it should be a list ofComponent
classes.
Learn more about using Media.
[project root]/components/calendar/calendar.pyfrom django_components import Component\n\nclass Calendar(Component):\n template_file = \"calendar.html\"\n js_file = \"calendar.js\"\n css_file = \"calendar.css\"\n\n class Media: # <--- new\n js = [\n \"path/to/shared.js\",\n \"https://unpkg.com/alpinejs@3.14.7/dist/cdn.min.js\", # AlpineJS\n ]\n css = [\n \"path/to/shared.css\",\n \"https://unpkg.com/tailwindcss@^2/dist/tailwind.min.css\", # Tailwind\n ]\n\n def get_context_data(self):\n return {\n \"date\": \"1970-01-01\",\n }\n
Note
Same as with the \"primary\" JS and CSS, the file paths files can be either:
- Relative to the Python component file (as seen above),
- Relative to any of the component directories as defined by
COMPONENTS.dirs
and/orCOMPONENTS.app_dirs
(e.g.[your apps]/components
dir and[project root]/components
)
Info
The
Media
nested class is shaped based on Django's Media class.As such, django-components allows multiple formats to define the nested Media class:
# Single files\nclass Media:\n js = \"calendar.js\"\n css = \"calendar.css\"\n\n# Lists of files\nclass Media:\n js = [\"calendar.js\", \"calendar2.js\"]\n css = [\"calendar.css\", \"calendar2.css\"]\n\n# Dictionary of media types for CSS\nclass Media:\n js = [\"calendar.js\", \"calendar2.js\"]\n css = {\n \"all\": [\"calendar.css\", \"calendar2.css\"],\n }\n
If you define a list of JS files, they will be executed one-by-one, left-to-right.
"},{"location":"getting_started/adding_js_and_css/#rules-of-execution-of-scripts-in-mediajs","title":"Rules of execution of scripts inMedia.js
","text":"The scripts defined in
Media.js
still follow the rules outlined above:- JS is executed in the order in which the components are found in the HTML.
- JS will be executed only once, even if there is multiple instances of the same component.
Additionally to
Media.js
applies that:- JS in
Media.js
is executed before the component's primary JS. - JS in
Media.js
is executed in the same order as it was defined. - If there is multiple components that specify the same JS path or URL in
Media.js
, this JS will be still loaded and executed only once.
Putting all of this together, our
Calendar
component above would render HTML like so:<html>\n <head>\n ...\n <!-- CSS from Media.css -->\n <link href=\"/static/path/to/shared.css\" media=\"all\" rel=\"stylesheet\" />\n <link\n href=\"https://unpkg.com/tailwindcss@^2/dist/tailwind.min.css\"\n media=\"all\"\n rel=\"stylesheet\"\n />\n <!-- CSS from Component.css_file -->\n <style>\n .calendar {\n width: 200px;\n background: pink;\n }\n .calendar span {\n font-weight: bold;\n }\n </style>\n </head>\n <body>\n ...\n <!-- JS from Media.js -->\n <script src=\"/static/path/to/shared.js\"></script>\n <script src=\"https://unpkg.com/alpinejs@3.14.7/dist/cdn.min.js\"></script>\n <!-- JS from Component.js_file -->\n <script>\n (function () {\n document.querySelector(\".calendar\").onclick = () => {\n alert(\"Clicked calendar!\");\n };\n })();\n </script>\n </body>\n</html>\n
Now that we have a fully-defined component, next let's use it in a Django template \u27a1\ufe0f.
"},{"location":"getting_started/adding_slots/","title":"Adding slots","text":"Our calendar component's looking great! But we just got a new assignment from our colleague - The calendar date needs to be shown on 3 different pages:
- On one page, it needs to be shown as is
- On the second, the date needs to be bold
- On the third, the date needs to be in italics
As a reminder, this is what the component's template looks like:
<div class=\"calendar\">\n Today's date is <span>{{ date }}</span>\n</div>\n
There's many ways we could approach this:
- Expose the date in a slot
- Style
.calendar > span
differently on different pages - Pass a variable to the component that decides how the date is rendered
- Create a new component
First two options are more flexible, because the custom styling is not baked into a component's implementation. And for the sake of demonstration, we'll solve this challenge with slots.
"},{"location":"getting_started/adding_slots/#1-what-are-slots","title":"1. What are slots","text":"Components support something called Slots.
When a component is used inside another template, slots allow the parent template to override specific parts of the child component by passing in different content.
This mechanism makes components more reusable and composable.
This behavior is similar to slots in Vue.
In the example below we introduce two tags that work hand in hand to make this work. These are...
{% slot <name> %}
/{% endslot %}
: Declares a new slot in the component template.{% fill <name> %}
/{% endfill %}
: (Used inside a{% component %}
tag pair.) Fills a declared slot with the specified content.
Let's update our calendar component to support more customization. We'll add
{% slot %}
tag to the template:<div class=\"calendar\">\n Today's date is\n {% slot \"date\" default %} {# <--- new #}\n <span>{{ date }}</span>\n {% endslot %}\n</div>\n
Notice that:
-
We named the slot
date
- so we can fill this slot by using{% fill \"date\" %}
-
We also made it the default slot.
-
We placed our original implementation inside the
{% slot %}
tag - this is what will be rendered when the slot is NOT overriden.
Now we can use
{% fill %}
tags inside the{% component %}
tags to override thedate
slot to generate the bold and italics variants:{# Default #}\n{% component \"calendar\" date=\"2024-12-13\" / %}\n\n{# Bold #}\n{% component \"calendar\" date=\"2024-12-13\" %}\n <b> 2024-12-13 </b>\n{% endcomponent %}\n\n{# Italics #}\n{% component \"calendar\" date=\"2024-12-13\" %}\n <i> 2024-12-13 </i>\n{% endcomponent %}\n
Which will render as:
<!-- Default -->\n<div class=\"calendar\">\n Today's date is <span>2024-12-13</span>\n</div>\n\n<!-- Bold -->\n<div class=\"calendar\">\n Today's date is <b>2024-12-13</b>\n</div>\n\n<!-- Italics -->\n<div class=\"calendar\">\n Today's date is <i>2024-12-13</i>\n</div>\n
Info
Since we used the
default
flag on{% slot \"date\" %}
inside our calendar component, we can target thedate
component in multiple ways:-
Explicitly by it's name
{% component \"calendar\" date=\"2024-12-13\" %}\n {% fill \"date\" %}\n <i> 2024-12-13 </i>\n {% endfill %}\n{% endcomponent %}\n
-
Implicitly as the default slot (Omitting the
{% fill %}
tag){% component \"calendar\" date=\"2024-12-13\" %}\n <i> 2024-12-13 </i>\n{% endcomponent %}\n
-
Explicitly as the default slot (Setting fill name to
default
){% component \"calendar\" date=\"2024-12-13\" %}\n {% fill \"default\" %}\n <i> 2024-12-13 </i>\n {% endfill %}\n{% endcomponent %}\n
There is a mistake in our code!
2024-12-13
is Friday, so that's fine. But if we updated the to2024-12-14
, which is Saturday, our template from previous step would render this:<!-- Default -->\n<div class=\"calendar\">\n Today's date is <span>2024-12-16</span>\n</div>\n\n<!-- Bold -->\n<div class=\"calendar\">\n Today's date is <b>2024-12-14</b>\n</div>\n\n<!-- Italics -->\n<div class=\"calendar\">\n Today's date is <i>2024-12-14</i>\n</div>\n
The first instance rendered
2024-12-16
, while the rest rendered2024-12-14
!Why? Remember that in the
[project root]/components/calendar/calendar.pyget_context_data()
method of our Calendar component, we pre-process the date. If the date falls on Saturday or Sunday, we shift it to next Monday:from datetime import date\n\nfrom django_components import Component, register\n\n# If date is Sat or Sun, shift it to next Mon, so the date is always workweek.\ndef to_workweek_date(d: date):\n ...\n\n@register(\"calendar\")\nclass Calendar(Component):\n template_file = \"calendar.html\"\n ...\n def get_context_data(self, date: date, extra_class: str | None = None):\n workweek_date = to_workweek_date(date)\n return {\n \"date\": workweek_date,\n \"extra_class\": extra_class,\n }\n
And the issue is that in our template, we used the
"},{"location":"getting_started/adding_slots/#5-adding-data-to-slots","title":"5. Adding data to slots","text":"date
value that we used as input, which is NOT the same as thedate
variable used inside Calendar's template.We want to use the same
date
variable that's used inside Calendar's template.Luckily, django-components allows passing data to the slot, also known as Scoped slots.
This consists of two steps:
- Pass the
date
variable to the{% slot %}
tag - Access the
date
variable in the{% fill %}
tag by using the specialdata
kwarg
Let's update the Calendar's template:
<div class=\"calendar\">\n Today's date is\n {% slot \"date\" default date=date %} {# <--- changed #}\n <span>{{ date }}</span>\n {% endslot %}\n</div>\n
Info
The
{% slot %}
tag has one special kwarg,name
. When you write{% slot \"date\" / %}\n
It's the same as:
{% slot name=\"date\" / %}\n
Other than the
name
kwarg, you can pass any extra kwargs to the{% slot %}
tag, and these will be exposed as the slot's data.
"},{"location":"getting_started/adding_slots/#6-accessing-slot-data-in-fills","title":"6. Accessing slot data in fills","text":"{% slot name=\"date\" kwarg1=123 kwarg2=\"text\" kwarg3=my_var / %}\n
Now, on the
{% fill %}
tags, we can use thedata
kwarg to specify the variable under which the slot data will be available.The variable from the
data
kwarg contains all the extra kwargs passed to the{% slot %}
tag.So if we set
data=\"slot_data\"
, then we can access the date variable underslot_data.date
:{# Default #}\n{% component \"calendar\" date=\"2024-12-13\" / %}\n\n{# Bold #}\n{% component \"calendar\" date=\"2024-12-13\" %}\n {% fill \"date\" data=\"slot_data\" %}\n <b> {{ slot_data.date }} </b>\n {% endfill %}\n{% endcomponent %}\n\n{# Italics #}\n{% component \"calendar\" date=\"2024-12-13\" %}\n {% fill \"date\" data=\"slot_data\" %}\n <i> {{ slot_data.date }} </i>\n {% endfill %}\n{% endcomponent %}\n
By using the
date
variable from the slot, we'll render the correct date each time:<!-- Default -->\n<div class=\"calendar\">\n Today's date is <span>2024-12-16</span>\n</div>\n\n<!-- Bold -->\n<div class=\"calendar\">\n Today's date is <b>2024-12-16</b>\n</div>\n\n<!-- Italics -->\n<div class=\"calendar\">\n Today's date is <i>2024-12-16</i>\n</div>\n
Info
When to use slots vs variables?
Generally, slots are more flexible - you can access the slot data, even the original slot content. Thus, slots behave more like functions that render content based on their context.
On the other hand, variables are static - the variable you pass to a component is what will be used.
Moreover, slots are treated as part of the template - for example the CSS scoping (work in progress) is applied to the slot content too.
"},{"location":"getting_started/components_in_templates/","title":"Components in templates","text":"By the end of this section, we want to be able to use our components in Django templates like so:
"},{"location":"getting_started/components_in_templates/#1-register-component","title":"1. Register component","text":"{% load component_tags %}\n<!DOCTYPE html>\n<html>\n <head>\n <title>My example calendar</title>\n </head>\n <body>\n {% component \"calendar\" / %}\n </body>\n<html>\n
First, however, we need to register our component class with
ComponentRegistry
.To register a component with a
[project root]/components/calendar/calendar.pyComponentRegistry
, we will use the@register
decorator, and give it a name under which the component will be accessible from within the template:from django_components import Component, register # <--- new\n\n@register(\"calendar\") # <--- new\nclass Calendar(Component):\n template_file = \"calendar.html\"\n js_file = \"calendar.js\"\n css_file = \"calendar.css\"\n\n def get_context_data(self):\n return {\n \"date\": \"1970-01-01\",\n }\n
This will register the component to the default registry. Default registry is loaded into the template by calling
{% load component_tags %}
inside the template.Info
Why do we have to register components?
We want to use our component as a template tag (
{% ... %}
) in Django template.In Django, template tags are managed by the
Library
instances. Whenever you include{% load xxx %}
in your template, you are loading aLibrary
instance into your template.ComponentRegistry
acts like a router and connects the registered components with the associatedLibrary
.That way, when you include
{% load component_tags %}
in your template, you are able to \"call\" components like{% component \"calendar\" / %}
.ComponentRegistries
also make it possible to group and share components as standalone packages. Learn more here.Note
You can create custom
ComponentRegistry
instances, which will use differentLibrary
instances. In that case you will have to load different libraries depending on which components you want to use:Example 1 - Using component defined in the default registry
{% load component_tags %}\n<div>\n {% component \"calendar\" / %}\n</div>\n
Example 2 - Using component defined in a custom registry
{% load my_custom_tags %}\n<div>\n {% my_component \"table\" / %}\n</div>\n
Note that, because the tag name
"},{"location":"getting_started/components_in_templates/#2-load-and-use-the-component-in-template","title":"2. Load and use the component in template","text":"component
is use by the default ComponentRegistry, the custom registry was configured to use the tagmy_component
instead. Read more hereThe component is now registered under the name
calendar
. All that remains to do is to load and render the component inside a template:{% load component_tags %} {# Load the default registry #}\n<!DOCTYPE html>\n<html>\n <head>\n <title>My example calendar</title>\n </head>\n <body>\n {% component \"calendar\" / %} {# Render the component #}\n </body>\n<html>\n
Info
Component tags should end with
/
if they do not contain any Slot fills. But you can also use{% endcomponent %}
instead:{% component \"calendar\" %}{% endcomponent %}\n
We defined the Calendar's template as
<div class=\"calendar\">\n Today's date is <span>{{ date }}</span>\n</div>\n
and the variable
date
as\"1970-01-01\"
.Thus, the final output will look something like this:
<!DOCTYPE html>\n<html>\n <head>\n <title>My example calendar</title>\n <style>\n .calendar {\n width: 200px;\n background: pink;\n }\n .calendar span {\n font-weight: bold;\n }\n </style>\n </head>\n <body>\n <div class=\"calendar\">\n Today's date is <span>1970-01-01</span>\n </div>\n <script>\n (function () {\n document.querySelector(\".calendar\").onclick = () => {\n alert(\"Clicked calendar!\");\n };\n })();\n </script>\n </body>\n<html>\n
This makes it possible to organize your front-end around reusable components, instead of relying on template tags and keeping your CSS and Javascript in the static directory.
Info
Remember that you can use
{% component_js_dependencies %}
and{% component_css_dependencies %}
to change where the<script>
and<style>
tags will be rendered (See JS and CSS output locations).Info
How does django-components pick up registered components?
Notice that it was enough to add
@register
to the component. We didn't need to import the component file anywhere to execute it.This is because django-components automatically imports all Python files found in the component directories during an event called Autodiscovery.
So with Autodiscovery, it's the same as if you manually imported the component files on the
ready()
hook:class MyApp(AppConfig):\n default_auto_field = \"django.db.models.BigAutoField\"\n name = \"myapp\"\n\n def ready(self):\n import myapp.components.calendar\n import myapp.components.table\n ...\n
You can now render the components in templates!
Currently our component always renders the same content. Let's parametrise it, so that our Calendar component is configurable from within the template \u27a1\ufe0f
"},{"location":"getting_started/parametrising_components/","title":"Parametrising components","text":"So far, our Calendar component will always render the date
1970-01-01
. Let's make it more useful and flexible by being able to pass in custom date.What we want is to be able to use the Calendar component within the template like so:
"},{"location":"getting_started/parametrising_components/#1-understading-component-inputs","title":"1. Understading component inputs","text":"{% component \"calendar\" date=\"2024-12-13\" extra_class=\"text-red\" / %}\n
In section Create your first component, we defined the
[project root]/components/calendar/calendar.pyget_context_data()
method that defines what variables will be available within the template:from django_components import Component, register\n\n@register(\"calendar\")\nclass Calendar(Component):\n template_file = \"calendar.html\"\n ...\n def get_context_data(self):\n return {\n \"date\": \"1970-01-01\",\n }\n
What we didn't say is that
get_context_data()
actually receives the args and kwargs that were passed to a component.So if we call a component with a
date
andextra_class
keywords:{% component \"calendar\" date=\"2024-12-13\" extra_class=\"text-red\" / %}\n
This is the same as calling:
Calendar.get_context_data(date=\"2024-12-13\", extra_class=\"text-red\")\n
And same applies to positional arguments, or mixing args and kwargs, where:
{% component \"calendar\" \"2024-12-13\" extra_class=\"text-red\" / %}\n
is same as
"},{"location":"getting_started/parametrising_components/#2-define-inputs-for-get_context_data","title":"2. Define inputs forCalendar.get_context_data(\"2024-12-13\", extra_class=\"text-red\")\n
get_context_data
","text":"Let's put this to test. We want to pass
[project root]/components/calendar/calendar.pydate
andextra_class
kwargs to the component. And so, we can write theget_context_data()
method such that it expects those parameters:from datetime import date\n\nfrom django_components import Component, register\n\n@register(\"calendar\")\nclass Calendar(Component):\n template_file = \"calendar.html\"\n ...\n def get_context_data(self, date: date, extra_class: str | None = None):\n return {\n \"date\": date,\n \"extra_class\": extra_class,\n }\n
Info
Since
get_context_data()
is just a regular Python function, type hints annotations work the same way as anywhere else.Warning
Since
get_context_data()
is just a regular Python function, it will raise TypeError if it receives incorrect parameters.Since
extra_class
is optional in the function signature, it's optional also in the template. So both following calls are valid:{% component \"calendar\" \"2024-12-13\" / %}\n{% component \"calendar\" \"2024-12-13\" extra_class=\"text-red\" / %}\n
However,
date
is required. Thus we MUST provide it. Same with regular Python functions,date
can be set either as positional or keyword argument. But either way it MUST be set:
"},{"location":"getting_started/parametrising_components/#3-process-inputs-in-get_context_data","title":"3. Process inputs in\u2705\n{% component \"calendar\" \"2024-12-13\" / %}\n{% component \"calendar\" extra_class=\"text-red\" date=\"2024-12-13\" / %}\n\n\u274c\n{% component \"calendar\" extra_class=\"text-red\" / %}\n
get_context_data
","text":"The
get_context_data()
method is powerful, because it allows us to decouple component inputs from the template variables. In other words, we can pre-process the component inputs, and massage them into a shape that's most appropriate for what the template needs. And it also allows us to pass in static data into the template.Imagine our component receives data from the database that looks like below (taken from Django).
cities = [\n {\"name\": \"Mumbai\", \"population\": \"19,000,000\", \"country\": \"India\"},\n {\"name\": \"Calcutta\", \"population\": \"15,000,000\", \"country\": \"India\"},\n {\"name\": \"New York\", \"population\": \"20,000,000\", \"country\": \"USA\"},\n {\"name\": \"Chicago\", \"population\": \"7,000,000\", \"country\": \"USA\"},\n {\"name\": \"Tokyo\", \"population\": \"33,000,000\", \"country\": \"Japan\"},\n]\n
We need to group the list items by size into following buckets by population:
- 0-10,000,000
- 10,000,001-20,000,000
- 20,000,001-30,000,000
- +30,000,001
So we want to end up with following data:
cities_by_pop = [\n {\n \"name\": \"0-10,000,000\",\n \"items\": [\n {\"name\": \"Chicago\", \"population\": \"7,000,000\", \"country\": \"USA\"},\n ]\n },\n {\n \"name\": \"10,000,001-20,000,000\",\n \"items\": [\n {\"name\": \"Calcutta\", \"population\": \"15,000,000\", \"country\": \"India\"},\n {\"name\": \"Mumbai\", \"population\": \"19,000,000\", \"country\": \"India\"},\n {\"name\": \"New York\", \"population\": \"20,000,000\", \"country\": \"USA\"},\n ]\n },\n {\n \"name\": \"30,000,001-40,000,000\",\n \"items\": [\n {\"name\": \"Tokyo\", \"population\": \"33,000,000\", \"country\": \"Japan\"},\n ]\n },\n]\n
Without the
get_context_data()
method, we'd have to either:- Pre-process the data in Python before passing it to the components.
- Define a Django filter or template tag to take the data and process it on the spot.
Instead, with
get_context_data()
, we can keep this transformation private to this component, and keep the rest of the codebase clean.def group_by_pop(data):\n ...\n\n@register(\"population_table\")\nclass PopulationTable(Component):\n template_file = \"population_table.html\"\n\n def get_context_data(self, data):\n return {\n \"data\": group_by_pop(data),\n }\n
Similarly we can make use of
[project root]/components/calendar/calendar.pyget_context_data()
to pre-process the date that was given to the component:
"},{"location":"getting_started/parametrising_components/#4-pass-inputs-to-components","title":"4. Pass inputs to components","text":"from datetime import date\n\nfrom django_components import Component, register\n\n# If date is Sat or Sun, shift it to next Mon, so the date is always workweek.\ndef to_workweek_date(d: date):\n ...\n\n@register(\"calendar\")\nclass Calendar(Component):\n template_file = \"calendar.html\"\n ...\n def get_context_data(self, date: date, extra_class: str | None = None):\n workweek_date = to_workweek_date(date) # <--- new\n return {\n \"date\": workweek_date, # <--- changed\n \"extra_class\": extra_class,\n }\n
Once we're happy with
Calendar.get_contex_data()
, we can update our templates to use the parametrized version of the component:<div>\n {% component \"calendar\" date=\"2024-12-13\" / %}\n {% component \"calendar\" date=\"1970-01-01\" / %}\n</div>\n
Next, you will learn how to use slots give your components even more flexibility \u27a1\ufe0f
"},{"location":"getting_started/your_first_component/","title":"Create your first component","text":"A component in django-components can be as simple as a Django template and Python code to declare the component:
calendar.html
calendar.py<div class=\"calendar\">\n Today's date is <span>{{ date }}</span>\n</div>\n
from django_components import Component\n\nclass Calendar(Component):\n template_file = \"calendar.html\"\n
Or a combination of Django template, Python, CSS, and Javascript:
calendar.html
calendar.css<div class=\"calendar\">\n Today's date is <span>{{ date }}</span>\n</div>\n
calendar.js.calendar {\n width: 200px;\n background: pink;\n}\n
calendar.pydocument.querySelector(\".calendar\").onclick = function () {\n alert(\"Clicked calendar!\");\n};\n
from django_components import Component\n\nclass Calendar(Component):\n template_file = \"calendar.html\"\n js_file = \"calendar.js\"\n css_file = \"calendar.css\"\n
Alternatively, you can \"inline\" HTML, JS, and CSS right into the component class:
from django_components import Component\n\nclass Calendar(Component):\n template = \"\"\"\n <div class=\"calendar\">\n Today's date is <span>{{ date }}</span>\n </div>\n \"\"\"\n\n css = \"\"\"\n .calendar {\n width: 200px;\n background: pink;\n }\n \"\"\"\n\n js = \"\"\"\n document.querySelector(\".calendar\").onclick = function () {\n alert(\"Clicked calendar!\");\n };\n \"\"\"\n
Note
If you \"inline\" the HTML, JS and CSS code into the Python class, you can set up syntax highlighting for better experience. However, autocompletion / intellisense does not work with syntax highlighting.
We'll start by creating a component that defines only a Django template:
"},{"location":"getting_started/your_first_component/#1-create-project-structure","title":"1. Create project structure","text":"Start by creating empty
calendar.py
andcalendar.html
files:
"},{"location":"getting_started/your_first_component/#2-write-django-template","title":"2. Write Django template","text":"sampleproject/\n\u251c\u2500\u2500 calendarapp/\n\u251c\u2500\u2500 components/ \ud83c\udd95\n\u2502 \u2514\u2500\u2500 calendar/ \ud83c\udd95\n\u2502 \u251c\u2500\u2500 calendar.py \ud83c\udd95\n\u2502 \u2514\u2500\u2500 calendar.html \ud83c\udd95\n\u251c\u2500\u2500 sampleproject/\n\u251c\u2500\u2500 manage.py\n\u2514\u2500\u2500 requirements.txt\n
Inside
[project root]/components/calendar/calendar.htmlcalendar.html
, write:<div class=\"calendar\">\n Today's date is <span>{{ date }}</span>\n</div>\n
In this example we've defined one template variable
date
. You can use any and as many variables as you like. These variables will be defined in the Python file inget_context_data()
when creating an instance of this component.Note
The template will be rendered with whatever template backend you've specified in your Django settings file.
Currently django-components supports only the default
"},{"location":"getting_started/your_first_component/#3-create-new-component-in-python","title":"3. Create new Component in Python","text":"\"django.template.backends.django.DjangoTemplates\"
template backend!In
calendar.py
, create a subclass of Component to create a new component.To link the HTML template with our component, set
[project root]/components/calendar/calendar.pytemplate_file
to the name of the HTML file.from django_components import Component\n\nclass Calendar(Component):\n template_file = \"calendar.html\"\n
Note
The path to the template file can be either:
- Relative to the component's python file (as seen above),
- Relative to any of the component directories as defined by
COMPONENTS.dirs
and/orCOMPONENTS.app_dirs
(e.g.[your apps]/components
dir and[project root]/components
)
In
calendar.html
, we've used the variabledate
. So we need to define it for the template to work.This is done using
[project root]/components/calendar/calendar.pyComponent.get_context_data()
. It's a function that returns a dictionary. The entries in this dictionary will become available within the template as variables, e.g. as{{ date }}
.from django_components import Component\n\nclass Calendar(Component):\n template_file = \"calendar.html\"\n\n def get_context_data(self):\n return {\n \"date\": \"1970-01-01\",\n }\n
Now, when we render the component with
Component.render()
method:Calendar.render()\n
It will output
<div class=\"calendar\">\n Today's date is <span>1970-01-01</span>\n</div>\n
And voil\u00e1!! We've created our first component.
Next, let's add JS and CSS to this component \u27a1\ufe0f.
"},{"location":"guides/devguides/dependency_mgmt/","title":"JS and CSS rendering","text":"Aim of this doc is to share the intuition on how we manage the JS and CSS (\"dependencies\") associated with components, and how we render them.
"},{"location":"guides/devguides/dependency_mgmt/#starting-conditions","title":"Starting conditions","text":"-
First of all, when we consider a component, it has two kind of dependencies - the \"inlined\" JS and CSS, and additional linked JS and CSS via
Media.js/css
:from django_components import Component, types\n\nclass MyTable(Component):\n # Inlined JS\n js: types.js = \"\"\"\n console.log(123);\n \"\"\"\n\n # Inlined CSS\n css: types.css = \"\"\"\n .my-table {\n color: red;\n }\n \"\"\"\n\n # Linked JS / CSS\n class Media:\n js = [\n \"script-one.js\", # STATIC file relative to component file\n \"/script-two.js\", # URL path\n \"https://example.com/script-three.js\", # URL\n ]\n\n css = [\n \"style-one.css\", # STATIC file relative to component file\n \"/style-two.css\", # URL path\n \"https://example.com/style-three.css\", # URL\n ]\n
-
Second thing to keep in mind is that all component's are eventually rendered into a string. And so, if we want to associate extra info with a rendered component, it has to be serialized to a string.
This is because a component may be embedded in a Django Template with the
{% component %}
tag, which, when rendered, is turned into a string:template = Template(\"\"\"\n {% load component_tags %}\n <div>\n {% component \"my_table\" / %}\n </div>\n\"\"\")\n\nhtml_str = template.render(Context({}))\n
And for this reason, we take the same approach also when we render a component with
Component.render()
- It returns a string. -
Thirdly, we also want to add support for JS / CSS variables. That is, that a variable defined on the component would be somehow accessible from within the JS script / CSS style.
A simple approach to this would be to modify the inlined JS / CSS directly, and insert them for each component. But if you had extremely large JS / CSS, and e.g. only a single JS / CSS variable that you want to insert, it would be wasteful to create a copy of the JS / CSS scripts for each component instance.
So instead, a preferred approach here is to defined and insert the inlined JS / CSS only once, and have some kind of mechanism on how we make correct the JS / CSS variables available only to the correct components.
-
Last important thing is that we want the JS / CSS dependencies to work also with HTML fragments.
So normally, e.g. when a user hits URL of a web page, the server renders full HTML document, with
<!doctype>
,<html>
,<head>
, and<body>
. In such case, we know about ALL JS and CSS dependencies at render time, so we can e.g. insert them into<head>
and<body>
ourselves.However this renders only the initial state. HTML fragments is a common pattern where interactivity is added to the web page by fetching and replacing bits of HTML on the main HTML document after some user action.
In the case of HTML fragments, the HTML is NOT a proper document, but only the HTML that will be inserted somewhere into the DOM.
The challenge here is that Django template for the HTML fragment MAY contain components, and these components MAY have inlined or linked JS and CSS.
def fragment_view(request):\n template = Template(\"\"\"\n {% load component_tags %}\n <div>\n {% component \"my_table\" / %}\n </div>\n \"\"\")\n\n fragment_str = template.render(Context({}))\n return HttpResponse(fragment_str, status=200)\n
User may use different libraries to fetch and insert the HTML fragments (e.g. HTMX, AlpineJS, ...). From our perspective, the only thing that we can reliably say is that we expect that the HTML fragment WILL be eventually inserted into the DOM.
So to include the corresponding JS and CSS, a simple approach could be to append them to the HTML as
<style>
and<script>
, e.g.:<!-- Original content -->\n<div>...</div>\n<!-- Associated CSS files -->\n<link href=\"http://...\" />\n<style>\n .my-class {\n color: red;\n }\n</style>\n<!-- Associated JS files -->\n<script src=\"http://...\"></script>\n<script>\n console.log(123);\n</script>\n
But this has a number of issues:
- The JS scripts would run for each instance of the component.
- Bloating of the HTML file, as each inlined JS or CSS would be included fully for each component.
- While this sound OK, this could really bloat the HTML files if we used a UI component library for the basic building blocks like buttons, lists, cards, etc.
So the solution should address all the points above. To achieve that, we manage the JS / CSS dependencies ourselves in the browser. So when a full HTML document is loaded, we keep track of which JS and CSS have been loaded. And when an HTML fragment is inserted, we check which JS / CSS dependencies it has, and load only those that have NOT been loaded yet.
This is how we achieve that:
-
When a component is rendered, it inserts an HTML comment containing metadata about the rendered component.
So a template like this
{% load component_tags %}\n<div>\n {% component \"my_table\" / %}\n</div>\n{% component \"button\" %}\n Click me!\n{% endcomponent %}\n
May actually render:
<div>\n <!-- _RENDERED \"my_table_10bc2c,c020ad\" -->\n <table>\n ...\n </table>\n</div>\n<!-- _RENDERED \"button_309dcf,31c0da\" -->\n<button>Click me!</button>\n
Each
<!-- _RENDERED -->
comment includes comma-separated data - a unique hash for the component class, e.g.my_table_10bc2c
, and the component ID, e.g.c020ad
.This way, we or the user can freely pass the rendered around or transform it, treating it as a string to add / remove / replace bits. As long as the
<!-- _RENDERED -->
comments remain in the rendered string, we will be able to deduce which JS and CSS dependencies the component needs. -
Post-process the rendered HTML, extracting the
<!-- _RENDERED -->
comments, and instead inserting the corresponding JS and CSS dependencies.If we dealt only with JS, then we could get away with processing the
<!-- _RENDERED -->
comments on the client (browser). However, the CSS needs to be processed still on the server, so the browser receives CSS styles already inserted as<style>
or<link>
HTML tags. Because if we do not do that, we get a flash of unstyled content, as there will be a delay between when the HTML page loaded and when the CSS was fetched and loaded.So, assuming that a user has already rendered their template, which still contains
<!-- _RENDERED -->
comments, we need to extract and process these comments.There's multiple ways to achieve this:
-
The approach recommended to the users is to use the
ComponentDependencyMiddleware
middleware, which scans all outgoing HTML, and post-processes the<!-- _RENDERED -->
comments. -
If users are using
Component.render()
orComponent.render_to_response()
, these post-process the<!-- _RENDERED -->
comments by default. -
NOTE: Users are able to opt out of the post-processing by setting
render_dependencies=False
. -
For advanced use cases, users may use
render_dependencies()
directly. This is the function that bothComponentDependencyMiddleware
andComponent.render()
call internally.
render_dependencies()
, whether called directly, via middleware or other way, does the following:-
Find all
<!-- _RENDERED -->
comments, and for each comment: -
Look up the corresponding component class.
-
Get the component's inlined JS / CSS from
Component.js/css
, and linked JS / CSS fromComponent.Media.js/css
. -
Generate JS script that loads the JS / CSS dependencies.
-
Insert the JS scripts either at the end of
<body>
, or in place of{% component_dependencies %}
/{% component_js_dependencies %}
tags. -
To avoid the flash of unstyled content, we need place the styles into the HTML instead of dynamically loading them from within a JS script. The CSS is placed either at the end of
<head>
, or in place of{% component_dependencies %}
/{% component_css_dependencies %}
-
We cache the component's inlined JS and CSS, so they can be fetched via an URL, so the inlined JS / CSS an be treated the same way as the JS / CSS dependencies set in
Component.Media.js/css
.- NOTE: While this is currently not entirely necessary, it opens up the doors for allowing plugins to post-process the inlined JS and CSS. Because after it has been post-processed, we need to store it somewhere.
-
-
Server returns the post-processed HTML.
-
In the browser, the generated JS script from step 2.4 is executed. It goes through all JS and CSS dependencies it was given. If some JS / CSS was already loaded, it is NOT fetched again. Otherwise it generates the corresponding
<script>
or<link>
HTML tags to load the JS / CSS dependencies.In the browser, the \"dependency manager JS\" may look like this:
// Load JS or CSS script if not loaded already\nComponents.loadJs('<script src=\"/abc/xyz/script.js\">');\nComponents.loadCss('<link href=\"/abc/xyz/style.css\">');\n\n// Or mark one as already-loaded, so it is ignored when\n// we call `loadJs`\nComponents.markScriptLoaded(\"js\", \"/abc/def\");\n
Note that
loadJs() / loadCss()
receive whole<script> / <link>
tags, not just the URL. This is because when Django'sMedia
class renders JS and CSS, it formats it as<script>
and<link>
tags. And we allow users to modify how the JS and CSS should be rendered into the<script>
and<link>
tags.So, if users decided to add an extra attribute to their
<script>
tags, e.g.<script defer src=\"http://...\"></script>
, then this way we make sure that thedefer
attribute will be present on the<script>
tag when it is inserted into the DOM at the time of loading the JS script. -
To be able to fetch component's inlined JS and CSS, django-components adds a URL path under:
/components/cache/<str:comp_cls_hash>.<str:script_type>/
E.g.
/components/cache/my_table_10bc2c.js/
This endpoint takes the component's unique hash, e.g.
my_table_10bc2c
, and looks up the component's inlined JS or CSS.
Thus, with this approach, we ensure that:
- All JS / CSS dependencies are loaded / executed only once.
- The approach is compatible with HTML fragments
- The approach is compatible with JS / CSS variables.
- Inlined JS / CSS may be post-processed by plugins
This doc serves as a primer on how component slots and fills are resolved.
"},{"location":"guides/devguides/slot_rendering/#flow","title":"Flow","text":"-
Imagine you have a template. Some kind of text, maybe HTML:
| ------\n| ---------\n| ----\n| -------\n
-
The template may contain some vars, tags, etc
| -- {{ my_var }} --\n| ---------\n| ----\n| -------\n
-
The template also contains some slots, etc
| -- {{ my_var }} --\n| ---------\n| -- {% slot \"myslot\" %} ---\n| -- {% endslot %} ---\n| ----\n| -- {% slot \"myslot2\" %} ---\n| -- {% endslot %} ---\n| -------\n
-
Slots may be nested
| -- {{ my_var }} --\n| -- ABC\n| -- {% slot \"myslot\" %} ---\n| ----- DEF {{ my_var }}\n| ----- {% slot \"myslot_inner\" %}\n| -------- GHI {{ my_var }}\n| ----- {% endslot %}\n| -- {% endslot %} ---\n| ----\n| -- {% slot \"myslot2\" %} ---\n| ---- JKL {{ my_var }}\n| -- {% endslot %} ---\n| -------\n
-
Some slots may be inside fills for other components
| -- {{ my_var }} --\n| -- ABC\n| -- {% slot \"myslot\" %}---\n| ----- DEF {{ my_var }}\n| ----- {% slot \"myslot_inner\" %}\n| -------- GHI {{ my_var }}\n| ----- {% endslot %}\n| -- {% endslot %} ---\n| ------\n| -- {% component \"mycomp\" %} ---\n| ---- {% slot \"myslot\" %} ---\n| ------- JKL {{ my_var }}\n| ------- {% slot \"myslot_inner\" %}\n| ---------- MNO {{ my_var }}\n| ------- {% endslot %}\n| ---- {% endslot %} ---\n| -- {% endcomponent %} ---\n| ----\n| -- {% slot \"myslot2\" %} ---\n| ---- PQR {{ my_var }}\n| -- {% endslot %} ---\n| -------\n
-
The names of the slots and fills may be defined using variables
| -- {% slot slot_name %} ---\n| ---- STU {{ my_var }}\n| -- {% endslot %} ---\n| -------\n
-
The slot and fill names may be defined using for loops or other variables defined within the template (e.g.
{% with %}
tag or{% ... as var %}
syntax)| -- {% for slot_name in slots %} ---\n| ---- {% slot slot_name %} ---\n| ------ STU {{ slot_name }}\n| ---- {% endslot %} ---\n| -- {% endfor %} ---\n| -------\n
-
Variables for names and for loops allow us implement \"passthrough slots\" - that is, taking all slots that our component received, and passing them to a child component, dynamically.
| -- {% component \"mycomp\" %} ---\n| ---- {% for slot_name in slots %} ---\n| ------ {% fill slot_name %} ---\n| -------- {% slot slot_name %} ---\n| ---------- XYZ {{ slot_name }}\n| --------- {% endslot %}\n| ------- {% endfill %}\n| ---- {% endfor %} ---\n| -- {% endcomponent %} ---\n| ----\n
-
Putting that all together, a document may look like this:
| -- {{ my_var }} --\n| -- ABC\n| -- {% slot \"myslot\" %}---\n| ----- DEF {{ my_var }}\n| ----- {% slot \"myslot_inner\" %}\n| -------- GHI {{ my_var }}\n| ----- {% endslot %}\n| -- {% endslot %} ---\n| ------\n| -- {% component \"mycomp\" %} ---\n| ---- {% slot \"myslot\" %} ---\n| ------- JKL {{ my_var }}\n| ------- {% slot \"myslot_inner\" %}\n| ---------- MNO {{ my_var }}\n| ------- {% endslot %}\n| ---- {% endslot %} ---\n| -- {% endcomponent %} ---\n| ----\n| -- {% slot \"myslot2\" %} ---\n| ---- PQR {{ my_var }}\n| -- {% endslot %} ---\n| -------\n| -- {% for slot_name in slots %} ---\n| ---- {% component \"mycomp\" %} ---\n| ------- {% slot slot_name %}\n| ---------- STU {{ slot_name }}\n| ------- {% endslot %}\n| ---- {% endcomponent %} ---\n| -- {% endfor %} ---\n| ----\n| -- {% component \"mycomp\" %} ---\n| ---- {% for slot_name in slots %} ---\n| ------ {% fill slot_name %} ---\n| -------- {% slot slot_name %} ---\n| ---------- XYZ {{ slot_name }}\n| --------- {% endslot %}\n| ------- {% endfill %}\n| ---- {% endfor %} ---\n| -- {% endcomponent %} ---\n| -------\n
-
Given the above, we want to render the slots with
{% fill %}
tag that were defined OUTSIDE of this template. How do I do that?NOTE: Before v0.110, slots were resolved statically, by walking down the Django Template and Nodes. However, this did not allow for using for loops or other variables defined in the template.
Currently, this consists of 2 steps:
-
If a component is rendered within a template using
{% component %}
tag, determine the given{% fill %}
tags in the component's body (the content in between{% component %}
and{% endcomponent %}
).After this step, we know about all the fills that were passed to the component.
-
Then we simply render the template as usual. And then we reach the
{% slot %}
tag, we search the context for the available fills.- If there IS a fill with the same name as the slot, we render the fill.
- If the slot is marked
default
, and there is a fill nameddefault
, then we render that. - Otherwise, we render the slot's default content.
-
-
Obtaining the fills from
{% fill %}
.When a component is rendered with
{% component %}
tag, and it has some content in between{% component %}
and{% endcomponent %}
, we want to figure out if that content is a default slot (no{% fill %}
used), or if there is a collection of named{% fill %}
tags:Default slot:
| -- {% component \"mycomp\" %} ---\n| ---- STU {{ slot_name }}\n| -- {% endcomponent %} ---\n
Named slots:
| -- {% component \"mycomp\" %} ---\n| ---- {% fill \"slot_a\" %}\n| ------ STU\n| ---- {% endslot %}\n| ---- {% fill \"slot_b\" %}\n| ------ XYZ\n| ---- {% endslot %}\n| -- {% endcomponent %} ---\n
To respect any forloops or other variables defined within the template to which the fills may have access, we:
- Render the content between
{% component %}
and{% endcomponent %}
using the context outside of the component. - When we reach a
{% fill %}
tag, we capture any variables that were created between the{% component %}
and{% fill %}
tags. - When we reach
{% fill %}
tag, we do not continue rendering deeper. Instead we make a record that we found the fill tag with given name, kwargs, etc. - After the rendering is done, we check if we've encountered any fills. If yes, we expect only named fills. If no, we assume that the the component's body is a default slot.
- Lastly we process the found fills, and make them available to the context, so any slots inside the component may access these fills.
- Render the content between
-
Rendering slots
Slot rendering works similarly to collecting fills, in a sense that we do not search for the slots ahead of the time, but instead let Django handle the rendering of the template, and we step in only when Django come across as
{% slot %}
tag.When we reach a slot tag, we search the context for the available fills.
- If there IS a fill with the same name as the slot, we render the fill.
- If the slot is marked
default
, and there is a fill nameddefault
, then we render that. - Otherwise, we render the slot's default content.
In previous section, we said that the
{% fill %}
tags should be already rendered by the time they are inserted into the{% slot %}
tags.This is not quite true. To help you understand, consider this complex case:
| -- {% for var in [1, 2, 3] %} ---\n| ---- {% component \"mycomp2\" %} ---\n| ------ {% fill \"first\" %}\n| ------- STU {{ my_var }}\n| ------- {{ var }}\n| ------ {% endfill %}\n| ------ {% fill \"second\" %}\n| -------- {% component var=var my_var=my_var %}\n| ---------- VWX {{ my_var }}\n| -------- {% endcomponent %}\n| ------ {% endfill %}\n| ---- {% endcomponent %} ---\n| -- {% endfor %} ---\n| -------\n
We want the forloop variables to be available inside the
{% fill %}
tags. Because of that, however, we CANNOT render the fills/slots in advance.Instead, our solution is closer to how Vue handles slots. In Vue, slots are effectively functions that accept a context variables and render some content.
While we do not wrap the logic in a function, we do PREPARE IN ADVANCE: 1. The content that should be rendered for each slot 2. The context variables from
get_context_data()
Thus, once we reach the
"},{"location":"guides/devguides/slots_and_blocks/","title":"Using{% slot %}
node, in it'srender()
method, we access the data above, and, depending on thecontext_behavior
setting, include the current context or not. For more info, seeSlotNode.render()
.slot
andblock
tags","text":"-
First let's clarify how
include
andextends
tags work inside components.When component template includes
include
orextends
tags, it's as if the \"included\" template was inlined. So if the \"included\" template containsslot
tags, then the component uses those slots.If you have a template
abc.html
:<div>\n hello\n {% slot \"body\" %}{% endslot %}\n</div>\n
And components that make use of
abc.html
viainclude
orextends
:from django_components import Component, register\n\n@register(\"my_comp_extends\")\nclass MyCompWithExtends(Component):\n template = \"\"\"{% extends \"abc.html\" %}\"\"\"\n\n@register(\"my_comp_include\")\nclass MyCompWithInclude(Component):\n template = \"\"\"{% include \"abc.html\" %}\"\"\"\n
Then you can set slot fill for the slot imported via
include/extends
:{% component \"my_comp_extends\" %}\n {% fill \"body\" %}\n 123\n {% endfill %}\n{% endcomponent %}\n
And it will render:
<div>\n hello\n 123\n</div>\n
-
Slot and block
If you have a template
abc.html
like so:<div>\n hello\n {% block inner %}\n 1\n {% slot \"body\" %}\n 2\n {% endslot %}\n {% endblock %}\n</div>\n
and component
my_comp
:@register(\"my_comp\")\nclass MyComp(Component):\n template_file = \"abc.html\"\n
Then:
-
Since the
block
wasn't overriden, you can use thebody
slot:{% component \"my_comp\" %}\n {% fill \"body\" %}\n XYZ\n {% endfill %}\n{% endcomponent %}\n
And we get:
<div>hello 1 XYZ</div>\n
-
blocks
CANNOT be overriden through thecomponent
tag, so something like this:{% component \"my_comp\" %}\n {% fill \"body\" %}\n XYZ\n {% endfill %}\n{% endcomponent %}\n{% block \"inner\" %}\n 456\n{% endblock %}\n
Will still render the component content just the same:
<div>hello 1 XYZ</div>\n
-
You CAN override the
block
tags ofabc.html
if the component template usesextends
. In that case, just as you would expect, theblock inner
insideabc.html
will renderOVERRIDEN
:@register(\"my_comp\")\nclass MyComp(Component):\ntemplate_file = \"\"\"\n{% extends \"abc.html\" %}\n\n {% block inner %}\n OVERRIDEN\n {% endblock %}\n \"\"\"\n ```\n
-
This is where it gets interesting (but still intuitive). You can insert even new
slots
inside these \"overriding\" blocks:@register(\"my_comp\")\nclass MyComp(Component):\n template_file = \"\"\"\n {% extends \"abc.html\" %}\n\n {% load component_tags %}\n {% block \"inner\" %}\n OVERRIDEN\n {% slot \"new_slot\" %}\n hello\n {% endslot %}\n {% endblock %}\n \"\"\"\n
And you can then pass fill for this
new_slot
when rendering the component:{% component \"my_comp\" %}\n {% fill \"new_slot\" %}\n XYZ\n {% endfill %}\n{% endcomponent %}\n
NOTE: Currently you can supply fills for both
new_slot
andbody
slots, and you will not get an error for an invalid/unknown slot name. But sincebody
slot is not rendered, it just won't do anything. So this renders the same as above:{% component \"my_comp\" %}\n {% fill \"new_slot\" %}\n XYZ\n {% endfill %}\n {% fill \"body\" %}\n www\n {% endfill %}\n{% endcomponent %}\n
-
As larger projects get more complex, it can be hard to debug issues. Django Components provides a number of tools and approaches that can help you with that.
"},{"location":"guides/other/troubleshooting/#component-and-slot-highlighting","title":"Component and slot highlighting","text":"Django Components provides a visual debugging feature that helps you understand the structure and boundaries of your components and slots. When enabled, it adds a colored border and a label around each component and slot on your rendered page.
To enable component and slot highlighting, set
debug_highlight_components
and/ordebug_highlight_slots
toTrue
in yoursettings.py
file:from django_components import ComponentsSettings\n\nCOMPONENTS = ComponentsSettings(\n debug_highlight_components=True,\n debug_highlight_slots=True,\n)\n
Components will be highlighted with a blue border and label:
While the slots will be highlighted with a red border and label:
Warning
Use this feature ONLY in during development. Do NOT use it in production.
"},{"location":"guides/other/troubleshooting/#component-path-in-errors","title":"Component path in errors","text":"When an error occurs, the error message will show the path to the component that caused the error. E.g.
KeyError: \"An error occured while rendering components MyPage > MyLayout > MyComponent > Childomponent(slot:content)\n
The error message contains also the slot paths, so if you have a template like this:
{% component \"my_page\" %}\n {% slot \"content\" %}\n {% component \"table\" %}\n {% slot \"header\" %}\n {% component \"table_header\" %}\n ... {# ERROR HERE #}\n {% endcomponent %}\n {% endslot %}\n {% endcomponent %}\n {% endslot %}\n{% endcomponent %}\n
Then the error message will show the path to the component that caused the error:
"},{"location":"guides/other/troubleshooting/#debug-and-trace-logging","title":"Debug and trace logging","text":"KeyError: \"An error occured while rendering components my_page > layout > layout(slot:content) > my_page(slot:content) > table > table(slot:header) > table_header > table_header(slot:content)\n
Django components supports logging with Django.
To configure logging for Django components, set the
django_components
logger inLOGGING
insettings.py
(below).Also see the
settings.py
file in sampleproject for a real-life example.import logging\nimport sys\n\nLOGGING = {\n 'version': 1,\n 'disable_existing_loggers': False,\n \"handlers\": {\n \"console\": {\n 'class': 'logging.StreamHandler',\n 'stream': sys.stdout,\n },\n },\n \"loggers\": {\n \"django_components\": {\n \"level\": logging.DEBUG,\n \"handlers\": [\"console\"],\n },\n },\n}\n
Info
To set TRACE level, set
\"level\"
to5
:
"},{"location":"guides/other/troubleshooting/#logger-levels","title":"Logger levels","text":"LOGGING = {\n \"loggers\": {\n \"django_components\": {\n \"level\": 5,\n \"handlers\": [\"console\"],\n },\n },\n}\n
As of v0.126, django-components primarily uses these logger levels:
DEBUG
: Report on loading associated HTML / JS / CSS files, autodiscovery, etc.TRACE
: Detailed interaction of components and slots. Logs when template tags, components, and slots are started / ended rendering, and when a slot is filled.
When you pass a slot fill to a Component, the component and slot names is remebered on the slot object.
Thus, you can check where a slot was filled from by printing it out:
class MyComponent(Component):\n def on_render_before(self):\n print(self.input.slots)\n
might print:
"},{"location":"guides/other/troubleshooting/#agentic-debugging","title":"Agentic debugging","text":"{\n 'content': <Slot component_name='layout' slot_name='content'>,\n 'header': <Slot component_name='my_page' slot_name='header'>,\n 'left_panel': <Slot component_name='layout' slot_name='left_panel'>,\n}\n
All the features above make django-components to work really well with coding AI agents like Github Copilot or CursorAI.
To debug component rendering with LLMs, you want to provide the LLM with:
- The components source code
- The rendered output
- As much additional context as possible
Your codebase already contains the components source code, but not the latter two.
"},{"location":"guides/other/troubleshooting/#providing-rendered-output","title":"Providing rendered output","text":"To provide the LLM with the rendered output, you can simply export the rendered output to a file.
rendered = ProjectPage.render(...)\nwith open(\"result.html\", \"w\") as f:\n f.write(rendered)\n
If you're using
render_to_response
, access the output from theHttpResponse
object:
"},{"location":"guides/other/troubleshooting/#providing-contextual-logs","title":"Providing contextual logs","text":"response = ProjectPage.render_to_response(...)\nwith open(\"result.html\", \"wb\") as f:\n f.write(response.content)\n
Next, we provide the agent with info on HOW we got the result that we have. We do so by providing the agent with the trace-level logs.
In your
settings.py
, configure the trace-level logs to be written to thedjango_components.log
file:
"},{"location":"guides/other/troubleshooting/#prompting-the-agent","title":"Prompting the agent","text":"LOGGING = {\n \"version\": 1,\n \"disable_existing_loggers\": False,\n \"handlers\": {\n \"file\": {\n \"class\": \"logging.FileHandler\",\n \"filename\": \"django_components.log\",\n \"mode\": \"w\", # Overwrite the file each time\n },\n },\n \"loggers\": {\n \"django_components\": {\n \"level\": 5,\n \"handlers\": [\"file\"],\n },\n },\n}\n
Now, you can prompt the agent and include the trace log and the rendered output to guide the agent with debugging.
I have a django-components (DJC) project. DJC is like if Vue or React component-based web development but made for Django ecosystem.
In the view
project_view
, I am rendering theProjectPage
component. However, the output is not as expected. The output is missing the tabs.You have access to the full log trace in
django_components.log
.You can also see the rendered output in
result.html
.With this information, help me debug the issue.
First, tell me what kind of info you would be looking for in the logs, and why (how it relates to understanding the cause of the bug).
Then tell me if that info was there, and what the implications are.
Finally, tell me what you would do to fix the issue.
"},{"location":"guides/setup/caching/","title":"Caching","text":"This page describes the kinds of assets that django-components caches and how to configure the cache backends.
"},{"location":"guides/setup/caching/#components-js-and-css-files","title":"Component's JS and CSS files","text":"django-components caches the JS and CSS files associated with your components. This enables components to be rendered as HTML fragments and still having the associated JS and CSS files loaded with them.
This includes:
- Inlined JS/CSS defined via
Component.js
andComponent.css
- JS/CSS variables generated from
get_js_data()
andget_css_data()
By default, django-components uses Django's local memory cache backend to store these assets. You can configure it to use any of your Django cache backends by setting the
COMPONENTS.cache
option in your settings:COMPONENTS = {\n # Name of the cache backend to use\n \"cache\": \"my-cache-backend\",\n}\n
The value should be the name of one of your configured cache backends from Django's
CACHES
setting.For example, to use Redis for caching component assets:
CACHES = {\n \"default\": {\n \"BACKEND\": \"django.core.cache.backends.locmem.LocMemCache\",\n },\n \"component-media\": {\n \"BACKEND\": \"django.core.cache.backends.redis.RedisCache\",\n \"LOCATION\": \"redis://127.0.0.1:6379/1\",\n }\n}\n\nCOMPONENTS = {\n # Use the Redis cache backend\n \"cache\": \"component-media\",\n}\n
See
"},{"location":"guides/setup/development_server/","title":"Development server","text":""},{"location":"guides/setup/development_server/#reload-dev-server-on-component-file-changes","title":"Reload dev server on component file changes","text":"COMPONENTS.cache
for more details about this setting.This is relevant if you are using the project structure as shown in our examples, where HTML, JS, CSS and Python are in separate files and nested in a directory.
In this case you may notice that when you are running a development server, the server sometimes does not reload when you change component files.
From relevant StackOverflow thread:
TL;DR is that the server won't reload if it thinks the changed file is in a templates directory, or in a nested sub directory of a templates directory. This is by design.
To make the dev server reload on all component files, set
reload_on_file_change
toTrue
. This configures Django to watch for component files too.Note
This setting should be enabled only for the dev environment!
"},{"location":"guides/setup/syntax_highlight/","title":"Syntax highlighting","text":""},{"location":"guides/setup/syntax_highlight/#vscode","title":"VSCode","text":"-
First install Python Inline Source Syntax Highlighting extension, it will give you syntax highlighting for the template, CSS, and JS.
-
Next, in your component, set typings of
Component.template/css/js
totypes.django_html
,types.css
, andtypes.js
respectively. The extension will recognize these and will activate syntax highlighting.
"},{"location":"guides/setup/syntax_highlight/#pycharm-or-other-jetbrains-ides","title":"Pycharm (or other Jetbrains IDEs)","text":"# In a file called [project root]/components/calendar.py\nfrom django_components import Component, register, types\n\n@register(\"calendar\")\nclass Calendar(Component):\n def get_context_data(self, date):\n return {\n \"date\": date,\n }\n\n template: types.django_html = \"\"\"\n <div class=\"calendar-component\">Today's date is <span>{{ date }}</span></div>\n \"\"\"\n\n css: types.css = \"\"\"\n .calendar-component { width: 200px; background: pink; }\n .calendar-component span { font-weight: bold; }\n \"\"\"\n\n js: types.js = \"\"\"\n (function(){\n if (document.querySelector(\".calendar-component\")) {\n document.querySelector(\".calendar-component\").onclick = function(){ alert(\"Clicked calendar!\"); };\n }\n })()\n \"\"\"\n
With PyCharm (or any other editor from Jetbrains), you don't need to use
types.django_html
,types.css
,types.js
since Pycharm uses language injections. You only need to write the comments# language=<lang>
above the variables.
"},{"location":"overview/code_of_conduct/","title":"Contributor Covenant Code of Conduct","text":""},{"location":"overview/code_of_conduct/#our-pledge","title":"Our Pledge","text":"from django_components import Component, register\n\n@register(\"calendar\")\nclass Calendar(Component):\n def get_context_data(self, date):\n return {\n \"date\": date,\n }\n\n # language=HTML\n template= \"\"\"\n <div class=\"calendar-component\">Today's date is <span>{{ date }}</span></div>\n \"\"\"\n\n # language=CSS\n css = \"\"\"\n .calendar-component { width: 200px; background: pink; }\n .calendar-component span { font-weight: bold; }\n \"\"\"\n\n # language=JS\n js = \"\"\"\n (function(){\n if (document.querySelector(\".calendar-component\")) {\n document.querySelector(\".calendar-component\").onclick = function(){ alert(\"Clicked calendar!\"); };\n }\n })()\n \"\"\"\n
In the interest of fostering an open and welcoming environment, we as contributors and maintainers pledge to making participation in our project and our community a harassment-free experience for everyone, regardless of age, body size, disability, ethnicity, sex characteristics, gender identity and expression, level of experience, education, socio-economic status, nationality, personal appearance, race, religion, or sexual identity and orientation.
"},{"location":"overview/code_of_conduct/#our-standards","title":"Our Standards","text":"Examples of behavior that contributes to creating a positive environment include:
- Using welcoming and inclusive language
- Being respectful of differing viewpoints and experiences
- Gracefully accepting constructive criticism
- Focusing on what is best for the community
- Showing empathy towards other community members
Examples of unacceptable behavior by participants include:
- The use of sexualized language or imagery and unwelcome sexual attention or advances
- Trolling, insulting/derogatory comments, and personal or political attacks
- Public or private harassment
- Publishing others' private information, such as a physical or electronic address, without explicit permission
- Other conduct which could reasonably be considered inappropriate in a professional setting
Project maintainers are responsible for clarifying the standards of acceptable behavior and are expected to take appropriate and fair corrective action in response to any instances of unacceptable behavior.
Project maintainers have the right and responsibility to remove, edit, or reject comments, commits, code, wiki edits, issues, and other contributions that are not aligned to this Code of Conduct, or to ban temporarily or permanently any contributor for other behaviors that they deem inappropriate, threatening, offensive, or harmful.
"},{"location":"overview/code_of_conduct/#scope","title":"Scope","text":"This Code of Conduct applies both within project spaces and in public spaces when an individual is representing the project or its community. Examples of representing a project or community include using an official project e-mail address, posting via an official social media account, or acting as an appointed representative at an online or offline event. Representation of a project may be further defined and clarified by project maintainers.
"},{"location":"overview/code_of_conduct/#enforcement","title":"Enforcement","text":"Instances of abusive, harassing, or otherwise unacceptable behavior may be reported by contacting the project team at emil@emilstenstrom.se. All complaints will be reviewed and investigated and will result in a response that is deemed necessary and appropriate to the circumstances. The project team is obligated to maintain confidentiality with regard to the reporter of an incident. Further details of specific enforcement policies may be posted separately.
Project maintainers who do not follow or enforce the Code of Conduct in good faith may face temporary or permanent repercussions as determined by other members of the project's leadership.
"},{"location":"overview/code_of_conduct/#attribution","title":"Attribution","text":"This Code of Conduct is adapted from the Contributor Covenant, version 1.4, available at https://www.contributor-covenant.org/version/1/4/code-of-conduct.html
For answers to common questions about this code of conduct, see https://www.contributor-covenant.org/faq
"},{"location":"overview/community/","title":"Community","text":""},{"location":"overview/community/#community-questions","title":"Community questions","text":"The best place to ask questions is in our Github Discussion board.
Please, before opening a new discussion, check if similar discussion wasn't opened already.
"},{"location":"overview/community/#community-examples","title":"Community examples","text":"One of our goals with
django-components
is to make it easy to share components between projects (see how to package components). If you have a set of components that you think would be useful to others, please open a pull request to add them to the list below.-
django-htmx-components: A set of components for use with htmx. Try out the live demo.
-
djc-heroicons: A component that renders icons from Heroicons.com.
Django-components supports all supported combinations versions of Django and Python.
Python version Django version 3.8 4.2 3.9 4.2 3.10 4.2, 5.0, 5.1 3.11 4.2, 5.0, 5.1 3.12 4.2, 5.0, 5.1 3.13 5.1"},{"location":"overview/contributing/","title":"Contributing","text":""},{"location":"overview/contributing/#bug-reports","title":"Bug reports","text":"If you find a bug, please open an issue with detailed description of what happened.
"},{"location":"overview/contributing/#bug-fixes","title":"Bug fixes","text":"If you found a fix for a bug or typo, go ahead and open a PR with a fix. We'll help you out with the rest!
"},{"location":"overview/contributing/#feature-requests","title":"Feature requests","text":"For feature requests or suggestions, please open either a discussion or an issue.
"},{"location":"overview/contributing/#getting-involved","title":"Getting involved","text":"django_components is still under active development, and there's much to build, so come aboard!
"},{"location":"overview/contributing/#sponsoring","title":"Sponsoring","text":"Another way you can get involved is by donating to the development of django_components.
"},{"location":"overview/development/","title":"Development","text":""},{"location":"overview/development/#install-locally-and-run-the-tests","title":"Install locally and run the tests","text":"Start by forking the project by clicking the Fork button up in the right corner in the GitHub. This makes a copy of the repository in your own name. Now you can clone this repository locally and start adding features:
git clone https://github.com/<your GitHub username>/django-components.git\ncd django-components\n
To quickly run the tests install the local dependencies by running:
pip install -r requirements-dev.txt\n
You also have to install this local django-components version. Use
-e
for editable mode so you don't have to re-install after every change:pip install -e .\n
Now you can run the tests to make sure everything works as expected:
pytest\n
The library is also tested across many versions of Python and Django. To run tests that way:
pyenv install -s 3.8\npyenv install -s 3.9\npyenv install -s 3.10\npyenv install -s 3.11\npyenv install -s 3.12\npyenv install -s 3.13\npyenv local 3.8 3.9 3.10 3.11 3.12 3.13\ntox -p\n
To run tests for a specific Python version, use:
tox -e py38\n
NOTE: See the available environments in
tox.ini
.And to run only linters, use:
"},{"location":"overview/development/#running-playwright-tests","title":"Running Playwright tests","text":"tox -e mypy,flake8,isort,black\n
We use Playwright for end-to-end tests. You will therefore need to install Playwright to be able to run these tests.
Luckily, Playwright makes it very easy:
pip install -r requirements-dev.txt\nplaywright install chromium --with-deps\n
After Playwright is ready, simply run the tests with
tox
:
"},{"location":"overview/development/#developing-against-live-django-app","title":"Developing against live Django app","text":"tox\n
How do you check that your changes to django-components project will work in an actual Django project?
Use the sampleproject demo project to validate the changes:
-
Navigate to sampleproject directory:
cd sampleproject\n
-
Install dependencies from the requirements.txt file:
pip install -r requirements.txt\n
-
Link to your local version of django-components:
pip install -e ..\n
Note
The path to the local version (in this case
..
) must point to the directory that has thesetup.py
file. -
Start Django server
python manage.py runserver\n
Once the server is up, it should be available at http://127.0.0.1:8000.
To display individual components, add them to the
"},{"location":"overview/development/#building-js-code","title":"Building JS code","text":"urls.py
, like in the case of http://127.0.0.1:8000/greetingdjango_components uses a bit of JS code to:
- Manage the loading of JS and CSS files used by the components
- Allow to pass data from Python to JS
When you make changes to this JS code, you also need to compile it:
-
Make sure you are inside
src/django_components_js
:cd src/django_components_js\n
-
Install the JS dependencies
npm install\n
-
Compile the JS/TS code:
python build.py\n
The script will combine all JS/TS code into a single
.js
file, minify it, and copy it todjango_components/static/django_components/django_components.min.js
.
To package the library into a distribution that can be published to PyPI, run:
# Install pypa/build\npython -m pip install build --user\n# Build a binary wheel and a source tarball\npython -m build --sdist --wheel --outdir dist/ .\n
To publish the package to PyPI, use
twine
(See Python user guide):twine upload --repository pypi dist/* -u __token__ -p <PyPI_TOKEN>\n
See the full workflow here.
"},{"location":"overview/development/#development-guides","title":"Development guides","text":"Head over to Dev guides for a deep dive into how django_components' features are implemented.
"},{"location":"overview/installation/","title":"Installation","text":"-
Install
django_components
into your environment:pip install django_components\n
-
Load
django_components
into Django by adding it intoINSTALLED_APPS
in in your settings file:INSTALLED_APPS = [\n ...,\n 'django_components',\n]\n
-
BASE_DIR
setting is required. Ensure that it is defined:from pathlib import Path\n\nBASE_DIR = Path(__file__).resolve().parent.parent\n
-
Optional. Set
COMPONENTS.dirs
and/orCOMPONENTS.app_dirs
so django_components knows where to find component HTML, JS and CSS files:If
COMPONENTS.dirs
is omitted, django-components will by default look for a top-level/components
directory,{BASE_DIR}/components
.from django_components import ComponentsSettings\n\nCOMPONENTS = ComponentsSettings(\n dirs=[\n ...,\n Path(BASE_DIR) / \"components\",\n ],\n)\n
In addition to
COMPONENTS.dirs
, django_components will also load components from app-level directories, such asmy-app/components/
. The directories within apps are configured withCOMPONENTS.app_dirs
, and the default is[app]/components
.Note
The input to
COMPONENTS.dirs
is the same as forSTATICFILES_DIRS
, and the paths must be full paths. See Django docs. -
Next, modify
TEMPLATES
section of settings.py as follows:- Remove
'APP_DIRS': True,
- NOTE: Instead of
APP_DIRS: True
, we will usedjango.template.loaders.app_directories.Loader
, which has the same effect.
- NOTE: Instead of
- Add
loaders
toOPTIONS
list and set it to following value:
This allows Django to load component HTML files as Django templates.
TEMPLATES = [\n {\n ...,\n 'OPTIONS': {\n 'loaders':[(\n 'django.template.loaders.cached.Loader', [\n # Default Django loader\n 'django.template.loaders.filesystem.Loader',\n # Including this is the same as APP_DIRS=True\n 'django.template.loaders.app_directories.Loader',\n # Components loader\n 'django_components.template_loader.Loader',\n ]\n )],\n },\n },\n]\n
- Remove
If you want to use JS or CSS with components, you will need to:
-
Add
\"django_components.finders.ComponentsFileSystemFinder\"
toSTATICFILES_FINDERS
in your settings file.This allows Django to serve component JS and CSS as static files.
STATICFILES_FINDERS = [\n # Default finders\n \"django.contrib.staticfiles.finders.FileSystemFinder\",\n \"django.contrib.staticfiles.finders.AppDirectoriesFinder\",\n # Django components\n \"django_components.finders.ComponentsFileSystemFinder\",\n]\n
-
Add
ComponentDependencyMiddleware
toMIDDLEWARE
setting.The middleware searches the outgoing HTML for all components that were rendered to generate the HTML, and adds the JS and CSS associated with those components.
MIDDLEWARE = [\n ...\n \"django_components.middleware.ComponentDependencyMiddleware\",\n]\n
Read more in Rendering JS/CSS dependencies.
-
Add django-component's URL paths to your
urlpatterns
:from django.urls import include, path\n\nurlpatterns = [\n ...\n path(\"\", include(\"django_components.urls\")),\n]\n
-
Optional. If you want to change where the JS and CSS is rendered, use
{% component_js_dependencies %}
and{% component_css_dependencies %}
.By default, the JS
<script>
and CSS<link>
tags are automatically inserted into the HTML (See JS and CSS output locations).<!doctype html>\n<html>\n <head>\n ...\n {% component_css_dependencies %}\n </head>\n <body>\n ...\n {% component_js_dependencies %}\n </body>\n</html>\n
-
Optional. By default, components' JS and CSS files are cached in memory.
If you want to change the cache backend, set the
COMPONENTS.cache
setting.Read more in Caching.
To avoid loading the app in each template using
{% load component_tags %}
, you can add the tag as a 'builtin' in settings.pyTEMPLATES = [\n {\n ...,\n 'OPTIONS': {\n 'builtins': [\n 'django_components.templatetags.component_tags',\n ]\n },\n },\n]\n
Now you're all set! Read on to find out how to build your first component.
"},{"location":"overview/license/","title":"License","text":"MIT License
Copyright (c) 2019 Emil Stenstr\u00f6m
Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the \"Software\"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:
The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED \"AS IS\", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
"},{"location":"overview/security_notes/","title":"Security notes \ud83d\udea8","text":"It is strongly recommended to read this section before using django-components in production.
"},{"location":"overview/security_notes/#static-files","title":"Static files","text":"TL;DR: No action needed from v0.100 onwards. Before v0.100, use
safer_staticfiles
to avoid exposing backend logic.Components can be organized however you prefer. That said, our prefered way is to keep the files of a component close together by bundling them in the same directory.
This means that files containing backend logic, such as Python modules and HTML templates, live in the same directory as static files, e.g. JS and CSS.
From v0.100 onwards, we keep component files (as defined by
COMPONENTS.dirs
andCOMPONENTS.app_dirs
) separate from the rest of the static files (defined bySTATICFILES_DIRS
). That way, the Python and HTML files are NOT exposed by the server. Only the static JS, CSS, and other common formats.Note
If you need to expose different file formats, you can configure these with
"},{"location":"overview/security_notes/#static-files-prior-to-v0100","title":"Static files prior to v0.100","text":"COMPONENTS.static_files_allowed
andCOMPONENTS.static_files_forbidden
.Prior to v0.100, if your were using django.contrib.staticfiles to collect static files, no distinction was made between the different kinds of files.
As a result, your Python code and templates may inadvertently become available on your static file server. You probably don't want this, as parts of your backend logic will be exposed, posing a potential security vulnerability.
From v0.27 until v0.100, django-components shipped with an additional installable app django_components.safer_staticfiles. It was a drop-in replacement for django.contrib.staticfiles. Its behavior is 100% identical except it ignores
.py
and.html
files, meaning these will not end up on your static files server.To use it, add it to
INSTALLED_APPS
and remove django.contrib.staticfiles.INSTALLED_APPS = [\n # 'django.contrib.staticfiles', # <-- REMOVE\n 'django_components',\n 'django_components.safer_staticfiles' # <-- ADD\n]\n
If you are on an pre-v0.27 version of django-components, your alternatives are:
- a) passing
--ignore <pattern>
options to the collecstatic CLI command, - b) defining a subclass of StaticFilesConfig.
Both routes are described in the official docs of the staticfiles app.
Note that
safer_staticfiles
excludes the.py
and.html
files for collectstatic command:python manage.py collectstatic\n
but it is ignored on the development server:
python manage.py runserver\n
For a step-by-step guide on deploying production server with static files, see the demo project.
See the older versions of the sampleproject for a setup with pre-v0.100 version.
"},{"location":"overview/welcome/","title":"Welcome to Django Components","text":"django-components
combines Django's templating system with the modularity seen in modern frontend frameworks like Vue or React.With
"},{"location":"overview/welcome/#quickstart","title":"Quickstart","text":"django-components
you can support Django projects small and large without leaving the Django ecosystem.A component in django-components can be as simple as a Django template and Python code to declare the component:
components/calendar/calendar.html
components/calendar/calendar.py<div class=\"calendar\">\n Today's date is <span>{{ date }}</span>\n</div>\n
from django_components import Component\n\nclass Calendar(Component):\n template_file = \"calendar.html\"\n
Or a combination of Django template, Python, CSS, and Javascript:
components/calendar/calendar.html
components/calendar/calendar.css<div class=\"calendar\">\n Today's date is <span>{{ date }}</span>\n</div>\n
components/calendar/calendar.js.calendar {\n width: 200px;\n background: pink;\n}\n
components/calendar/calendar.pydocument.querySelector(\".calendar\").onclick = function () {\n alert(\"Clicked calendar!\");\n};\n
from django_components import Component\n\nclass Calendar(Component):\n template_file = \"calendar.html\"\n js_file = \"calendar.js\"\n css_file = \"calendar.css\"\n\n def get_context_data(self, date):\n return {\"date\": date}\n
Use the component like this:
{% component \"calendar\" date=\"2024-11-06\" %}{% endcomponent %}\n
And this is what gets rendered:
<div class=\"calendar-component\">\n Today's date is <span>2024-11-06</span>\n</div>\n
Read on to learn about all the exciting details and configuration possibilities!
(If you instead prefer to jump right into the code, check out the example project)
"},{"location":"overview/welcome/#features","title":"Features","text":""},{"location":"overview/welcome/#modern-and-modular-ui","title":"Modern and modular UI","text":"- Create self-contained, reusable UI elements.
- Each component can include its own HTML, CSS, and JS, or additional third-party JS and CSS.
- HTML, CSS, and JS can be defined on the component class, or loaded from files.
"},{"location":"overview/welcome/#composition-with-slots","title":"Composition with slots","text":"from django_components import Component\n\n@register(\"calendar\")\nclass Calendar(Component):\n template = \"\"\"\n <div class=\"calendar\">\n Today's date is\n <span>{{ date }}</span>\n </div>\n \"\"\"\n\n css = \"\"\"\n .calendar {\n width: 200px;\n background: pink;\n }\n \"\"\"\n\n js = \"\"\"\n document.querySelector(\".calendar\")\n .addEventListener(\"click\", () => {\n alert(\"Clicked calendar!\");\n });\n \"\"\"\n\n # Additional JS and CSS\n class Media:\n js = [\"https://cdn.jsdelivr.net/npm/htmx.org@2.1.1/dist/htmx.min.js\"]\n css = [\"bootstrap/dist/css/bootstrap.min.css\"]\n\n # Variables available in the template\n def get_context_data(self, date):\n return {\n \"date\": date\n }\n
- Render components inside templates with
{% component %}
tag. - Compose them with
{% slot %}
and{% fill %}
tags. - Vue-like slot system, including scoped slots.
"},{"location":"overview/welcome/#extended-template-tags","title":"Extended template tags","text":"{% component \"Layout\"\n bookmarks=bookmarks\n breadcrumbs=breadcrumbs\n%}\n {% fill \"header\" %}\n <div class=\"flex justify-between gap-x-12\">\n <div class=\"prose\">\n <h3>{{ project.name }}</h3>\n </div>\n <div class=\"font-semibold text-gray-500\">\n {{ project.start_date }} - {{ project.end_date }}\n </div>\n </div>\n {% endfill %}\n\n {# Access data passed to `{% slot %}` with `data` #}\n {% fill \"tabs\" data=\"tabs_data\" %}\n {% component \"TabItem\" header=\"Project Info\" %}\n {% component \"ProjectInfo\"\n project=project\n project_tags=project_tags\n attrs:class=\"py-5\"\n attrs:width=tabs_data.width\n / %}\n {% endcomponent %}\n {% endfill %}\n{% endcomponent %}\n
django-components
extends Django's template tags syntax with:- Literal lists and dictionaries in template tags
- Self-closing tags
{% mytag / %}
- Multi-line template tags
- Spread operator
...
to dynamically pass args or kwargs into the template tag - Nested template tags like
\"{{ first_name }} {{ last_name }}\"
- Flat definition of dictionary keys
attr:key=val
"},{"location":"overview/welcome/#html-fragment-support","title":"HTML fragment support","text":"{% component \"table\"\n ...default_attrs\n title=\"Friend list for {{ user.name }}\"\n headers=[\"Name\", \"Age\", \"Email\"]\n data=[\n {\n \"name\": \"John\"|upper,\n \"age\": 30|add:1,\n \"email\": \"john@example.com\",\n \"hobbies\": [\"reading\"],\n },\n {\n \"name\": \"Jane\"|upper,\n \"age\": 25|add:1,\n \"email\": \"jane@example.com\",\n \"hobbies\": [\"reading\", \"coding\"],\n },\n ],\n attrs:class=\"py-4 ma-2 border-2 border-gray-300 rounded-md\"\n/ %}\n
django-components
makes intergration with HTMX, AlpineJS or jQuery easy by allowing components to be rendered as HTML fragments:-
Components's JS and CSS is loaded automatically when the fragment is inserted into the DOM
-
Expose components as views with
get
,post
,put
,patch
,delete
methods
"},{"location":"overview/welcome/#type-hints","title":"Type hints","text":"# components/calendar/calendar.py\n@register(\"calendar\")\nclass Calendar(Component):\n template_file = \"calendar.html\"\n\n def get(self, request, *args, **kwargs):\n page = request.GET.get(\"page\", 1)\n return self.render_to_response(\n kwargs={\n \"page\": page,\n }\n )\n\n def get_context_data(self, page):\n return {\n \"page\": page,\n }\n\n# urls.py\npath(\"calendar/\", Calendar.as_view()),\n
Opt-in to type hints by defining types for component's args, kwargs, slots, and more:
from typing import NotRequired, Tuple, TypedDict, SlotContent, SlotFunc\n\nButtonArgs = Tuple[int, str]\n\nclass ButtonKwargs(TypedDict):\n variable: str\n another: int\n maybe_var: NotRequired[int] # May be omitted\n\nclass ButtonData(TypedDict):\n variable: str\n\nclass ButtonSlots(TypedDict):\n my_slot: NotRequired[SlotFunc]\n another_slot: SlotContent\n\nButtonType = Component[ButtonArgs, ButtonKwargs, ButtonSlots, ButtonData, JsData, CssData]\n\nclass Button(ButtonType):\n def get_context_data(self, *args, **kwargs):\n self.input.args[0] # int\n self.input.kwargs[\"variable\"] # str\n self.input.slots[\"my_slot\"] # SlotFunc[MySlotData]\n\n return {} # Error: Key \"variable\" is missing\n
When you then call
Button.render()
orButton.render_to_response()
, you will get type hints:
"},{"location":"overview/welcome/#debugging-features","title":"Debugging features","text":"Button.render(\n # Error: First arg must be `int`, got `float`\n args=(1.25, \"abc\"),\n # Error: Key \"another\" is missing\n kwargs={\n \"variable\": \"text\",\n },\n)\n
- Visual component inspection: Highlight components and slots directly in your browser.
- Detailed tracing logs to supply AI-agents with context: The logs include component and slot names and IDs, and their position in the tree.
- Install and use third-party components from PyPI
- Or publish your own \"component registry\"
-
Highly customizable - Choose how the components are called in the template (and more):
{% component \"calendar\" date=\"2024-11-06\" %}\n{% endcomponent %}\n\n{% calendar date=\"2024-11-06\" %}\n{% endcalendar %}\n
- Vue-like provide / inject system
- Format HTML attributes with
{% html_attrs %}
Read the Release Notes to see the latest features and fixes.
"},{"location":"overview/welcome/#community-examples","title":"Community examples","text":"One of our goals with
"},{"location":"overview/welcome/#contributing-and-development","title":"Contributing and development","text":"django-components
is to make it easy to share components between projects. Head over to the Community examples to see some examples.Get involved or sponsor this project - See here
Running django-components locally for development - See here
"},{"location":"reference/api/","title":"Api","text":""},{"location":"reference/api/#api","title":"API","text":""},{"location":"reference/api/#django_components.BaseNode","title":"BaseNode","text":"BaseNode(\n params: List[TagAttr], flags: Optional[Dict[str, bool]] = None, nodelist: Optional[NodeList] = None, node_id: Optional[str] = None\n)\n
Bases:
django.template.base.Node
See source code
Node class for all django-components custom template tags.
This class has a dual role:
-
It declares how a particular template tag should be parsed - By setting the
tag
,end_tag
, andallowed_flags
attributes:class SlotNode(BaseNode):\n tag = \"slot\"\n end_tag = \"endslot\"\n allowed_flags = [\"required\"]\n
This will allow the template tag
{% slot %}
to be used like this:{% slot required %} ... {% endslot %}\n
-
The
render
method is the actual implementation of the template tag.This is where the tag's logic is implemented:
class MyNode(BaseNode):\n tag = \"mynode\"\n\n def render(self, context: Context, name: str, **kwargs: Any) -> str:\n return f\"Hello, {name}!\"\n
This will allow the template tag
{% mynode %}
to be used like this:{% mynode name=\"John\" %}\n
The template tag accepts parameters as defined on the
render
method's signature.For more info, see
BaseNode.render()
.Methods:
-
parse
\u2013 -
register
\u2013 -
render
\u2013 -
unregister
\u2013
Attributes:
-
active_flags
(List[str]
) \u2013 -
allowed_flags
(Optional[List[str]]
) \u2013 -
end_tag
(Optional[str]
) \u2013 -
flags
\u2013 -
node_id
\u2013 -
nodelist
\u2013 -
params
\u2013 -
tag
(str
) \u2013
property
","text":"active_flags: List[str]\n
See source code
Flags that were set for this specific instance.
"},{"location":"reference/api/#django_components.BaseNode.allowed_flags","title":"allowed_flagsclass-attribute
instance-attribute
","text":"allowed_flags: Optional[List[str]] = None\n
See source code
The allowed flags for this tag.
E.g.
"},{"location":"reference/api/#django_components.BaseNode.end_tag","title":"end_tag[\"required\"]
will allow this tag to be used like{% slot required %}
.class-attribute
instance-attribute
","text":"end_tag: Optional[str] = None\n
See source code
The end tag name.
E.g.
\"endcomponent\"
or\"endslot\"
will make this class match template tags{% endcomponent %}
or{% endslot %}
.If not set, then this template tag has no end tag.
So instead of
"},{"location":"reference/api/#django_components.BaseNode.flags","title":"flags{% component %} ... {% endcomponent %}
, you'd use only{% component %}
.instance-attribute
","text":"
"},{"location":"reference/api/#django_components.BaseNode.node_id","title":"node_idflags = flags or {flag: Falsefor flag in allowed_flags or []}\n
instance-attribute
","text":"
"},{"location":"reference/api/#django_components.BaseNode.nodelist","title":"nodelistnode_id = node_id or gen_id()\n
instance-attribute
","text":"
"},{"location":"reference/api/#django_components.BaseNode.params","title":"paramsnodelist = nodelist or NodeList()\n
instance-attribute
","text":"
"},{"location":"reference/api/#django_components.BaseNode.tag","title":"tagparams = params\n
instance-attribute
","text":"tag: str\n
See source code
The tag name.
E.g.
"},{"location":"reference/api/#django_components.BaseNode.parse","title":"parse\"component\"
or\"slot\"
will make this class match template tags{% component %}
or{% slot %}
.classmethod
","text":"parse(parser: Parser, token: Token, **kwargs: Any) -> BaseNode\n
See source code
This function is what is passed to Django's
Library.tag()
when registering the tag.In other words, this method is called by Django's template parser when we encounter a tag that matches this node's tag, e.g.
{% component %}
or{% slot %}
.To register the tag, you can use
"},{"location":"reference/api/#django_components.BaseNode.register","title":"registerBaseNode.register()
.classmethod
","text":"register(library: Library) -> None\n
See source code
A convenience method for registering the tag with the given library.
class MyNode(BaseNode):\n tag = \"mynode\"\n\nMyNode.register(library)\n
Allows you to then use the node in templates like so:
"},{"location":"reference/api/#django_components.BaseNode.render","title":"render","text":"{% load mylibrary %}\n{% mynode %}\n
render(context: Context, *args: Any, **kwargs: Any) -> str\n
See source code
Render the node. This method is meant to be overridden by subclasses.
The signature of this function decides what input the template tag accepts.
The
render()
method MUST accept acontext
argument. Any arguments after that will be part of the tag's input parameters.So if you define a
render
method like this:def render(self, context: Context, name: str, **kwargs: Any) -> str:\n
Then the tag will require the
name
parameter, and accept any extra keyword arguments:
"},{"location":"reference/api/#django_components.BaseNode.unregister","title":"unregister{% component name=\"John\" age=20 %}\n
classmethod
","text":"unregister(library: Library) -> None\n
See source code
Unregisters the node from the given library.
"},{"location":"reference/api/#django_components.Component","title":"Component","text":"Component(registered_name: Optional[str] = None, outer_context: Optional[Context] = None, registry: Optional[ComponentRegistry] = None)\n
Methods:
-
as_view
\u2013 -
get_context_data
\u2013 -
get_template
\u2013 -
get_template_name
\u2013 -
inject
\u2013 -
on_render_after
\u2013 -
on_render_before
\u2013 -
render
\u2013 -
render_to_response
\u2013
Attributes:
-
Media
(Optional[Type[ComponentMediaInput]]
) \u2013 -
View
\u2013 -
css
(Optional[str]
) \u2013 -
css_file
(Optional[str]
) \u2013 -
id
(str
) \u2013 -
input
(RenderInput[ArgsType, KwargsType, SlotsType]
) \u2013 -
is_filled
(SlotIsFilled
) \u2013 -
js
(Optional[str]
) \u2013 -
js_file
(Optional[str]
) \u2013 -
media
(Optional[Media]
) \u2013 -
media_class
(Type[Media]
) \u2013 -
name
(str
) \u2013 -
outer_context
(Optional[Context]
) \u2013 -
registered_name
(Optional[str]
) \u2013 -
registry
\u2013 -
response_class
\u2013 -
template
(Optional[Union[str, Template]]
) \u2013 -
template_file
(Optional[str]
) \u2013 -
template_name
(Optional[str]
) \u2013
class-attribute
instance-attribute
","text":"Media: Optional[Type[ComponentMediaInput]] = None\n
See source code
Defines JS and CSS media files associated with this component.
This
Media
class behaves similarly to Django's Media class:- Paths are generally handled as static file paths, and resolved URLs are rendered to HTML with
media_class.render_js()
ormedia_class.render_css()
. - A path that starts with
http
,https
, or/
is considered a URL, skipping the static file resolution. This path is still rendered to HTML withmedia_class.render_js()
ormedia_class.render_css()
. - A
SafeString
(with__html__
method) is considered an already-formatted HTML tag, skipping both static file resolution and rendering withmedia_class.render_js()
ormedia_class.render_css()
. - You can set
extend
to configure whether to inherit JS / CSS from parent components. See Controlling Media Inheritance.
However, there's a few differences from Django's Media class:
- Our Media class accepts various formats for the JS and CSS files: either a single file, a list, or (CSS-only) a dictionary (See
ComponentMediaInput
). - Individual JS / CSS files can be any of
str
,bytes
,Path
,SafeString
, or a function (SeeComponentMediaInputPath
).
Example:
"},{"location":"reference/api/#django_components.Component.View","title":"Viewclass MyTable(Component):\n class Media:\n js = [\n \"path/to/script.js\",\n \"https://unpkg.com/alpinejs@3.14.7/dist/cdn.min.js\", # AlpineJS\n ]\n css = {\n \"all\": [\n \"path/to/style.css\",\n \"https://unpkg.com/tailwindcss@^2/dist/tailwind.min.css\", # TailwindCSS\n ],\n \"print\": [\"path/to/style2.css\"],\n }\n
class-attribute
instance-attribute
","text":"
"},{"location":"reference/api/#django_components.Component.css","title":"cssView = ComponentView\n
class-attribute
instance-attribute
","text":"css: Optional[str] = None\n
See source code
Main CSS associated with this component inlined as string.
Only one of
css
orcss_file
must be defined.Example:
"},{"location":"reference/api/#django_components.Component.css_file","title":"css_fileclass MyComponent(Component):\n css = \"\"\"\n .my-class {\n color: red;\n }\n \"\"\"\n
class-attribute
instance-attribute
","text":"css_file: Optional[str] = None\n
See source code
Main CSS associated with this component as file path.
The filepath must be either:
- Relative to the directory where the Component's Python file is defined.
- Relative to one of the component directories, as set by
COMPONENTS.dirs
orCOMPONENTS.app_dirs
(e.g.<root>/components/
). - Relative to the staticfiles directories, as set by Django's
STATICFILES_DIRS
setting (e.g.<root>/static/
).
When you create a Component class with
css_file
, these will happen:- If the file path is relative to the directory where the component's Python file is, the path is resolved.
- The file is read and its contents is set to
Component.css
.
Only one of
css
orcss_file
must be defined.Example:
path/to/style.css
path/to/component.py.my-class {\n color: red;\n}\n
"},{"location":"reference/api/#django_components.Component.id","title":"idclass MyComponent(Component):\n css_file = \"path/to/style.css\"\n\nprint(MyComponent.css)\n# Output:\n# .my-class {\n# color: red;\n# };\n
property
","text":"id: str\n
See source code
This ID is unique for every time a
Component.render()
(or equivalent) is called (AKA \"render ID\").This is useful for logging or debugging.
Raises
RuntimeError
if accessed outside of rendering execution.A single render ID has a chance of collision 1 in 3.3M. However, due to birthday paradox, the chance of collision increases when approaching ~1,000 render IDs.
Thus, there is a soft-cap of 1,000 components rendered on a single page.
If you need to more than that, please open an issue on GitHub.
Example:
"},{"location":"reference/api/#django_components.Component.input","title":"inputclass MyComponent(Component):\n def get_context_data(self):\n print(f\"Rendering '{self.id}'\")\n return {}\n\nMyComponent.render()\n# Rendering 'ab3c4d'\n
property
","text":"input: RenderInput[ArgsType, KwargsType, SlotsType]\n
See source code
Input holds the data (like arg, kwargs, slots) that were passed to the current execution of the
"},{"location":"reference/api/#django_components.Component.is_filled","title":"is_filledrender
method.property
","text":"is_filled: SlotIsFilled\n
See source code
Dictionary describing which slots have or have not been filled.
This attribute is available for use only within the template as
"},{"location":"reference/api/#django_components.Component.js","title":"js{{ component_vars.is_filled.slot_name }}
, and withinon_render_before
andon_render_after
hooks.class-attribute
instance-attribute
","text":"js: Optional[str] = None\n
See source code
Main JS associated with this component inlined as string.
Only one of
js
orjs_file
must be defined.Example:
"},{"location":"reference/api/#django_components.Component.js_file","title":"js_fileclass MyComponent(Component):\n js = \"console.log('Hello, World!');\"\n
class-attribute
instance-attribute
","text":"js_file: Optional[str] = None\n
See source code
Main JS associated with this component as file path.
The filepath must be either:
- Relative to the directory where the Component's Python file is defined.
- Relative to one of the component directories, as set by
COMPONENTS.dirs
orCOMPONENTS.app_dirs
(e.g.<root>/components/
). - Relative to the staticfiles directories, as set by Django's
STATICFILES_DIRS
setting (e.g.<root>/static/
).
When you create a Component class with
js_file
, these will happen:- If the file path is relative to the directory where the component's Python file is, the path is resolved.
- The file is read and its contents is set to
Component.js
.
Only one of
js
orjs_file
must be defined.Example:
path/to/script.js
path/to/component.pyconsole.log('Hello, World!');\n
"},{"location":"reference/api/#django_components.Component.media","title":"mediaclass MyComponent(Component):\n js_file = \"path/to/script.js\"\n\nprint(MyComponent.js)\n# Output: console.log('Hello, World!');\n
class-attribute
instance-attribute
","text":"media: Optional[Media] = None\n
See source code
Normalized definition of JS and CSS media files associated with this component.
None
ifComponent.Media
is not defined.This field is generated from
Component.media_class
.Read more on Accessing component's HTML / JS / CSS.
Example:
"},{"location":"reference/api/#django_components.Component.media_class","title":"media_classclass MyComponent(Component):\n class Media:\n js = \"path/to/script.js\"\n css = \"path/to/style.css\"\n\nprint(MyComponent.media)\n# Output:\n# <script src=\"/static/path/to/script.js\"></script>\n# <link href=\"/static/path/to/style.css\" media=\"all\" rel=\"stylesheet\">\n
class-attribute
instance-attribute
","text":"media_class: Type[Media] = Media\n
See source code
Set the Media class that will be instantiated with the JS and CSS media files from
Component.Media
.This is useful when you want to customize the behavior of the media files, like customizing how the JS or CSS files are rendered into
<script>
or<link>
HTML tags. Read more in Defining HTML / JS / CSS files.Example:
"},{"location":"reference/api/#django_components.Component.name","title":"nameclass MyTable(Component):\n class Media:\n js = \"path/to/script.js\"\n css = \"path/to/style.css\"\n\n media_class = MyMediaClass\n
property
","text":"
"},{"location":"reference/api/#django_components.Component.outer_context","title":"outer_contextname: str\n
instance-attribute
","text":"
"},{"location":"reference/api/#django_components.Component.registered_name","title":"registered_nameouter_context: Optional[Context] = outer_context\n
instance-attribute
","text":"
"},{"location":"reference/api/#django_components.Component.registry","title":"registryregistered_name: Optional[str] = registered_name\n
instance-attribute
","text":"
"},{"location":"reference/api/#django_components.Component.response_class","title":"response_classregistry = registry or registry\n
class-attribute
instance-attribute
","text":"response_class = HttpResponse\n
See source code
This allows to configure what class is used to generate response from
"},{"location":"reference/api/#django_components.Component.template","title":"templaterender_to_response
class-attribute
instance-attribute
","text":"template: Optional[Union[str, Template]] = None\n
See source code
Inlined Django template associated with this component. Can be a plain string or a Template instance.
Only one of
template_file
,get_template_name
,template
orget_template
must be defined.Example:
"},{"location":"reference/api/#django_components.Component.template_file","title":"template_fileclass MyComponent(Component):\n template = \"Hello, {{ name }}!\"\n\n def get_context_data(self):\n return {\"name\": \"World\"}\n
class-attribute
instance-attribute
","text":"template_file: Optional[str] = None\n
See source code
Filepath to the Django template associated with this component.
The filepath must be either:
- Relative to the directory where the Component's Python file is defined.
- Relative to one of the component directories, as set by
COMPONENTS.dirs
orCOMPONENTS.app_dirs
(e.g.<root>/components/
). - Relative to the template directories, as set by Django's
TEMPLATES
setting (e.g.<root>/templates/
).
Only one of
template_file
,get_template_name
,template
orget_template
must be defined.Example:
"},{"location":"reference/api/#django_components.Component.template_name","title":"template_nameclass MyComponent(Component):\n template_file = \"path/to/template.html\"\n\n def get_context_data(self):\n return {\"name\": \"World\"}\n
instance-attribute
","text":"template_name: Optional[str]\n
See source code
Alias for
template_file
.For historical reasons, django-components used
template_name
to align with Django's TemplateView.template_file
was introduced to align withjs/js_file
andcss/css_file
.Setting and accessing this attribute is proxied to
"},{"location":"reference/api/#django_components.Component.as_view","title":"as_viewtemplate_file
.classmethod
","text":"as_view(**initkwargs: Any) -> ViewFn\n
See source code
Shortcut for calling
"},{"location":"reference/api/#django_components.Component.get_context_data","title":"get_context_data","text":"Component.View.as_view
and passing component instance to it.
"},{"location":"reference/api/#django_components.Component.get_template","title":"get_template","text":"get_context_data(*args: Any, **kwargs: Any) -> DataType\n
get_template(context: Context) -> Optional[Union[str, Template]]\n
See source code
Inlined Django template associated with this component. Can be a plain string or a Template instance.
Only one of
"},{"location":"reference/api/#django_components.Component.get_template_name","title":"get_template_name","text":"template_file
,get_template_name
,template
orget_template
must be defined.get_template_name(context: Context) -> Optional[str]\n
See source code
Filepath to the Django template associated with this component.
The filepath must be relative to either the file where the component class was defined, or one of the roots of
STATIFILES_DIRS
.Only one of
"},{"location":"reference/api/#django_components.Component.inject","title":"inject","text":"template_file
,get_template_name
,template
orget_template
must be defined.inject(key: str, default: Optional[Any] = None) -> Any\n
See source code
Use this method to retrieve the data that was passed to a
{% provide %}
tag with the corresponding key.To retrieve the data,
inject()
must be called inside a component that's inside the{% provide %}
tag.You may also pass a default that will be used if the
provide
tag with given key was NOT found.This method mut be used inside the
get_context_data()
method and raises an error if called elsewhere.Example:
Given this template:
{% provide \"provider\" hello=\"world\" %}\n {% component \"my_comp\" %}\n {% endcomponent %}\n{% endprovide %}\n
And given this definition of \"my_comp\" component:
from django_components import Component, register\n\n@register(\"my_comp\")\nclass MyComp(Component):\n template = \"hi {{ data.hello }}!\"\n def get_context_data(self):\n data = self.inject(\"provider\")\n return {\"data\": data}\n
This renders into:
hi world!\n
As the
"},{"location":"reference/api/#django_components.Component.on_render_after","title":"on_render_after","text":"{{ data.hello }}
is taken from the \"provider\".on_render_after(context: Context, template: Template, content: str) -> Optional[SlotResult]\n
See source code
Hook that runs just after the component's template was rendered. It receives the rendered output as the last argument.
You can use this hook to access the context or the template, but modifying them won't have any effect.
To override the content that gets rendered, you can return a string or SafeString from this hook.
"},{"location":"reference/api/#django_components.Component.on_render_before","title":"on_render_before","text":"on_render_before(context: Context, template: Template) -> None\n
See source code
Hook that runs just before the component's template is rendered.
You can use this hook to access or modify the context or the template.
"},{"location":"reference/api/#django_components.Component.render","title":"renderclassmethod
","text":"render(\n context: Optional[Union[Dict[str, Any], Context]] = None,\n args: Optional[ArgsType] = None,\n kwargs: Optional[KwargsType] = None,\n slots: Optional[SlotsType] = None,\n escape_slots_content: bool = True,\n type: RenderType = \"document\",\n render_dependencies: bool = True,\n request: Optional[HttpRequest] = None,\n) -> str\n
See source code
Render the component into a string.
Inputs: -
args
- Positional args for the component. This is the same as calling the component as{% component \"my_comp\" arg1 arg2 ... %}
-kwargs
- Kwargs for the component. This is the same as calling the component as{% component \"my_comp\" key1=val1 key2=val2 ... %}
-slots
- Component slot fills. This is the same as pasing{% fill %}
tags to the component. Accepts a dictionary of{ slot_name: slot_content }
whereslot_content
can be a string or render function. -escape_slots_content
- Whether the content fromslots
should be escaped. -context
- A context (dictionary or Django's Context) within which the component is rendered. The keys on the context can be accessed from within the template. - NOTE: In \"isolated\" mode, context is NOT accessible, and data MUST be passed via component's args and kwargs. -type
- Configure how to handle JS and CSS dependencies. -\"document\"
(default) - JS dependencies are inserted into{% component_js_dependencies %}
, or to the end of the<body>
tag. CSS dependencies are inserted into{% component_css_dependencies %}
, or the end of the<head>
tag. -render_dependencies
- Set this toFalse
if you want to insert the resulting HTML into another component. -request
- The request object. This is only required when needing to use RequestContext, e.g. to enable templatecontext_processors
. Unused if context is already an instance ofContext
Example:
"},{"location":"reference/api/#django_components.Component.render_to_response","title":"render_to_responseMyComponent.render(\n args=[1, \"two\", {}],\n kwargs={\n \"key\": 123,\n },\n slots={\n \"header\": 'STATIC TEXT HERE',\n \"footer\": lambda ctx, slot_kwargs, slot_ref: f'CTX: {ctx['hello']} SLOT_DATA: {slot_kwargs['abc']}',\n },\n escape_slots_content=False,\n)\n
classmethod
","text":"render_to_response(\n context: Optional[Union[Dict[str, Any], Context]] = None,\n slots: Optional[SlotsType] = None,\n escape_slots_content: bool = True,\n args: Optional[ArgsType] = None,\n kwargs: Optional[KwargsType] = None,\n type: RenderType = \"document\",\n request: Optional[HttpRequest] = None,\n *response_args: Any,\n **response_kwargs: Any\n) -> HttpResponse\n
See source code
Render the component and wrap the content in the response class.
The response class is taken from
Component.response_class
. Defaults todjango.http.HttpResponse
.This is the interface for the
django.views.View
class which allows us to use components as Django views withcomponent.as_view()
.Inputs: -
args
- Positional args for the component. This is the same as calling the component as{% component \"my_comp\" arg1 arg2 ... %}
-kwargs
- Kwargs for the component. This is the same as calling the component as{% component \"my_comp\" key1=val1 key2=val2 ... %}
-slots
- Component slot fills. This is the same as pasing{% fill %}
tags to the component. Accepts a dictionary of{ slot_name: slot_content }
whereslot_content
can be a string or render function. -escape_slots_content
- Whether the content fromslots
should be escaped. -context
- A context (dictionary or Django's Context) within which the component is rendered. The keys on the context can be accessed from within the template. - NOTE: In \"isolated\" mode, context is NOT accessible, and data MUST be passed via component's args and kwargs. -type
- Configure how to handle JS and CSS dependencies. -\"document\"
(default) - JS dependencies are inserted into{% component_js_dependencies %}
, or to the end of the<body>
tag. CSS dependencies are inserted into{% component_css_dependencies %}
, or the end of the<head>
tag. -request
- The request object. This is only required when needing to use RequestContext, e.g. to enable templatecontext_processors
. Unused if context is already an instance ofContext
Any additional args and kwargs are passed to the
response_class
.Example:
"},{"location":"reference/api/#django_components.ComponentFileEntry","title":"ComponentFileEntry","text":"MyComponent.render_to_response(\n args=[1, \"two\", {}],\n kwargs={\n \"key\": 123,\n },\n slots={\n \"header\": 'STATIC TEXT HERE',\n \"footer\": lambda ctx, slot_kwargs, slot_ref: f'CTX: {ctx['hello']} SLOT_DATA: {slot_kwargs['abc']}',\n },\n escape_slots_content=False,\n # HttpResponse input\n status=201,\n headers={...},\n)\n# HttpResponse(content=..., status=201, headers=...)\n
Bases:
tuple
See source code
Result returned by
get_component_files()
.Attributes:
-
dot_path
(str
) \u2013 -
filepath
(Path
) \u2013
instance-attribute
","text":"dot_path: str\n
See source code
The python import path for the module. E.g.
"},{"location":"reference/api/#django_components.ComponentFileEntry.filepath","title":"filepathapp.components.mycomp
instance-attribute
","text":"filepath: Path\n
See source code
The filesystem path to the module. E.g.
"},{"location":"reference/api/#django_components.ComponentMediaInput","title":"ComponentMediaInput","text":"/path/to/project/app/components/mycomp.py
Bases:
typing.Protocol
See source code
Defines JS and CSS media files associated with a
Component
.class MyTable(Component):\n class Media:\n js = [\n \"path/to/script.js\",\n \"https://unpkg.com/alpinejs@3.14.7/dist/cdn.min.js\", # AlpineJS\n ]\n css = {\n \"all\": [\n \"path/to/style.css\",\n \"https://unpkg.com/tailwindcss@^2/dist/tailwind.min.css\", # TailwindCSS\n ],\n \"print\": [\"path/to/style2.css\"],\n }\n
Attributes:
-
css
(Optional[Union[ComponentMediaInputPath, List[ComponentMediaInputPath], Dict[str, ComponentMediaInputPath], Dict[str, List[ComponentMediaInputPath]]]]
) \u2013 -
extend
(Union[bool, List[Type[Component]]]
) \u2013 -
js
(Optional[Union[ComponentMediaInputPath, List[ComponentMediaInputPath]]]
) \u2013
class-attribute
instance-attribute
","text":"css: Optional[\n Union[\n ComponentMediaInputPath, List[ComponentMediaInputPath], Dict[str, ComponentMediaInputPath], Dict[str, List[ComponentMediaInputPath]]\n ]\n] = None\n
See source code
CSS files associated with a
Component
.-
If a string, it's assumed to be a path to a CSS file.
-
If a list, each entry is assumed to be a path to a CSS file.
-
If a dict, the keys are media types (e.g. \"all\", \"print\", \"screen\", etc.), and the values are either:
- A string, assumed to be a path to a CSS file.
- A list, each entry is assumed to be a path to a CSS file.
Each entry can be a string, bytes, SafeString, PathLike, or a callable that returns one of the former (see
ComponentMediaInputPath
).Examples:
class MyComponent(Component):\n class Media:\n css = \"path/to/style.css\"\n
class MyComponent(Component):\n class Media:\n css = [\"path/to/style1.css\", \"path/to/style2.css\"]\n
class MyComponent(Component):\n class Media:\n css = {\n \"all\": \"path/to/style.css\",\n \"print\": \"path/to/print.css\",\n }\n
"},{"location":"reference/api/#django_components.ComponentMediaInput.extend","title":"extendclass MyComponent(Component):\n class Media:\n css = {\n \"all\": [\"path/to/style1.css\", \"path/to/style2.css\"],\n \"print\": \"path/to/print.css\",\n }\n
class-attribute
instance-attribute
","text":"extend: Union[bool, List[Type[Component]]] = True\n
See source code
Configures whether the component should inherit the media files from the parent component.
- If
True
, the component inherits the media files from the parent component. - If
False
, the component does not inherit the media files from the parent component. - If a list of components classes, the component inherits the media files ONLY from these specified components.
Read more in Controlling Media Inheritance section.
Example:
Disable media inheritance:
class ParentComponent(Component):\n class Media:\n js = [\"parent.js\"]\n\nclass MyComponent(ParentComponent):\n class Media:\n extend = False # Don't inherit parent media\n js = [\"script.js\"]\n\nprint(MyComponent.media._js) # [\"script.js\"]\n
Specify which components to inherit from. In this case, the media files are inherited ONLY from the specified components, and NOT from the original parent components:
"},{"location":"reference/api/#django_components.ComponentMediaInput.js","title":"jsclass ParentComponent(Component):\n class Media:\n js = [\"parent.js\"]\n\nclass MyComponent(ParentComponent):\n class Media:\n # Only inherit from these, ignoring the files from the parent\n extend = [OtherComponent1, OtherComponent2]\n\n js = [\"script.js\"]\n\nprint(MyComponent.media._js) # [\"script.js\", \"other1.js\", \"other2.js\"]\n
class-attribute
instance-attribute
","text":"js: Optional[Union[ComponentMediaInputPath, List[ComponentMediaInputPath]]] = None\n
See source code
JS files associated with a
Component
.-
If a string, it's assumed to be a path to a JS file.
-
If a list, each entry is assumed to be a path to a JS file.
Each entry can be a string, bytes, SafeString, PathLike, or a callable that returns one of the former (see
ComponentMediaInputPath
).Examples:
class MyComponent(Component):\n class Media:\n js = \"path/to/script.js\"\n
class MyComponent(Component):\n class Media:\n js = [\"path/to/script1.js\", \"path/to/script2.js\"]\n
"},{"location":"reference/api/#django_components.ComponentMediaInputPath","title":"ComponentMediaInputPathclass MyComponent(Component):\n class Media:\n js = lambda: [\"path/to/script1.js\", \"path/to/script2.js\"]\n
module-attribute
","text":"ComponentMediaInputPath = Union[str, bytes, SafeData, Path, PathLike, Callable[[], Union[str, bytes, SafeData, Path, PathLike]]]\n
See source code
A type representing an entry in Media.js or Media.css.
If an entry is a SafeString (or has
__html__
method), then entry is assumed to be a formatted HTML tag. Otherwise, it's assumed to be a path to a file.Example:
"},{"location":"reference/api/#django_components.ComponentRegistry","title":"ComponentRegistry","text":"class MyComponent\n class Media:\n js = [\n \"path/to/script.js\",\n b\"script.js\",\n SafeString(\"<script src='path/to/script.js'></script>\"),\n ]\n css = [\n Path(\"path/to/style.css\"),\n lambda: \"path/to/style.css\",\n lambda: Path(\"path/to/style.css\"),\n ]\n
ComponentRegistry(\n library: Optional[Library] = None, settings: Optional[Union[RegistrySettings, Callable[[ComponentRegistry], RegistrySettings]]] = None\n)\n
Bases:
object
See source code
Manages components and makes them available in the template, by default as
{% component %}
tags.{% component \"my_comp\" key=value %}\n{% endcomponent %}\n
To enable a component to be used in a template, the component must be registered with a component registry.
When you register a component to a registry, behind the scenes the registry automatically adds the component's template tag (e.g.
{% component %}
to theLibrary
. And the opposite happens when you unregister a component - the tag is removed.See Registering components.
Parameters:
-
library
(Library
, default:None
) \u2013Django
Library
associated with this registry. If omitted, the default Library instance from django_components is used. -
settings
(Union[RegistrySettings, Callable[[ComponentRegistry], RegistrySettings]]
, default:None
) \u2013Configure how the components registered with this registry will behave when rendered. See
RegistrySettings
. Can be either a static value or a callable that returns the settings. If omitted, the settings fromCOMPONENTS
are used.
Notes:
- The default registry is available as
django_components.registry
. - The default registry is used when registering components with
@register
decorator.
Example:
"},{"location":"reference/api/#django_components.ComponentRegistry--using-registry-to-share-components","title":"Using registry to share components","text":"# Use with default Library\nregistry = ComponentRegistry()\n\n# Or a custom one\nmy_lib = Library()\nregistry = ComponentRegistry(library=my_lib)\n\n# Usage\nregistry.register(\"button\", ButtonComponent)\nregistry.register(\"card\", CardComponent)\nregistry.all()\nregistry.clear()\nregistry.get()\n
You can use component registry for isolating or \"packaging\" components:
-
Create new instance of
ComponentRegistry
and Library:my_comps = Library()\nmy_comps_reg = ComponentRegistry(library=my_comps)\n
-
Register components to the registry:
my_comps_reg.register(\"my_button\", ButtonComponent)\nmy_comps_reg.register(\"my_card\", CardComponent)\n
-
In your target project, load the Library associated with the registry:
{% load my_comps %}\n
-
Use the registered components in your templates:
{% component \"button\" %}\n{% endcomponent %}\n
Methods:
-
all
\u2013 -
clear
\u2013 -
get
\u2013 -
register
\u2013 -
unregister
\u2013
Attributes:
-
library
(Library
) \u2013 -
settings
(InternalRegistrySettings
) \u2013
property
","text":"library: Library\n
See source code
The template tag
"},{"location":"reference/api/#django_components.ComponentRegistry.settings","title":"settingsLibrary
that is associated with the registry.property
","text":"settings: InternalRegistrySettings\n
See source code
Registry settings configured for this registry.
"},{"location":"reference/api/#django_components.ComponentRegistry.all","title":"all","text":"all() -> Dict[str, Type[Component]]\n
See source code
Retrieve all registered
Component
classes.Returns:
-
Dict[str, Type[Component]]
\u2013Dict[str, Type[Component]]: A dictionary of component names to component classes
Example:
"},{"location":"reference/api/#django_components.ComponentRegistry.clear","title":"clear","text":"# First register components\nregistry.register(\"button\", ButtonComponent)\nregistry.register(\"card\", CardComponent)\n# Then get all\nregistry.all()\n# > {\n# > \"button\": ButtonComponent,\n# > \"card\": CardComponent,\n# > }\n
clear() -> None\n
See source code
Clears the registry, unregistering all components.
Example:
"},{"location":"reference/api/#django_components.ComponentRegistry.get","title":"get","text":"# First register components\nregistry.register(\"button\", ButtonComponent)\nregistry.register(\"card\", CardComponent)\n# Then clear\nregistry.clear()\n# Then get all\nregistry.all()\n# > {}\n
get(name: str) -> Type[Component]\n
See source code
Retrieve a
Component
class registered under the given name.Parameters:
-
name
(str
) \u2013The name under which the component was registered. Required.
Returns:
-
Type[Component]
\u2013Type[Component]: The component class registered under the given name.
Raises:
NotRegistered
if the given name is not registered.
Example:
"},{"location":"reference/api/#django_components.ComponentRegistry.register","title":"register","text":"# First register component\nregistry.register(\"button\", ButtonComponent)\n# Then get\nregistry.get(\"button\")\n# > ButtonComponent\n
register(name: str, component: Type[Component]) -> None\n
See source code
Register a
Component
class with this registry under the given name.A component MUST be registered before it can be used in a template such as:
{% component \"my_comp\" %}\n{% endcomponent %}\n
Parameters:
-
name
(str
) \u2013The name under which the component will be registered. Required.
-
component
(Type[Component]
) \u2013The component class to register. Required.
Raises:
AlreadyRegistered
if a different component was already registered under the same name.
Example:
"},{"location":"reference/api/#django_components.ComponentRegistry.unregister","title":"unregister","text":"registry.register(\"button\", ButtonComponent)\n
unregister(name: str) -> None\n
See source code
Unregister the
Component
class that was registered under the given name.Once a component is unregistered, it is no longer available in the templates.
Parameters:
-
name
(str
) \u2013The name under which the component is registered. Required.
Raises:
NotRegistered
if the given name is not registered.
Example:
"},{"location":"reference/api/#django_components.ComponentVars","title":"ComponentVars","text":"# First register component\nregistry.register(\"button\", ButtonComponent)\n# Then unregister\nregistry.unregister(\"button\")\n
Bases:
tuple
See source code
Type for the variables available inside the component templates.
All variables here are scoped under
component_vars.
, so e.g. attributeis_filled
on this class is accessible inside the template as:{{ component_vars.is_filled }}\n
Attributes:
-
is_filled
(Dict[str, bool]
) \u2013
instance-attribute
","text":"is_filled: Dict[str, bool]\n
See source code
Dictonary describing which component slots are filled (
True
) or are not (False
).New in version 0.70
Use as
{{ component_vars.is_filled }}
Example:
{# Render wrapping HTML only if the slot is defined #}\n{% if component_vars.is_filled.my_slot %}\n <div class=\"slot-wrapper\">\n {% slot \"my_slot\" / %}\n </div>\n{% endif %}\n
This is equivalent to checking if a given key is among the slot fills:
"},{"location":"reference/api/#django_components.ComponentView","title":"ComponentView","text":"class MyTable(Component):\n def get_context_data(self, *args, **kwargs):\n return {\n \"my_slot_filled\": \"my_slot\" in self.input.slots\n }\n
ComponentView(component: Component, **kwargs: Any)\n
Bases:
django.views.generic.base.View
See source code
Subclass of
django.views.View
where theComponent
instance is available viaself.component
.Attributes:
-
component
\u2013
class-attribute
instance-attribute
","text":"
"},{"location":"reference/api/#django_components.ComponentsSettings","title":"ComponentsSettings","text":"component = component\n
Bases:
tuple
See source code
Settings available for django_components.
Example:
COMPONENTS = ComponentsSettings(\n autodiscover=False,\n dirs = [BASE_DIR / \"components\"],\n)\n
Attributes:
-
app_dirs
(Optional[Sequence[str]]
) \u2013 -
autodiscover
(Optional[bool]
) \u2013 -
cache
(Optional[str]
) \u2013 -
context_behavior
(Optional[ContextBehaviorType]
) \u2013 -
debug_highlight_components
(Optional[bool]
) \u2013 -
debug_highlight_slots
(Optional[bool]
) \u2013 -
dirs
(Optional[Sequence[Union[str, PathLike, Tuple[str, str], Tuple[str, PathLike]]]]
) \u2013 -
dynamic_component_name
(Optional[str]
) \u2013 -
forbidden_static_files
(Optional[List[Union[str, Pattern]]]
) \u2013 -
libraries
(Optional[List[str]]
) \u2013 -
multiline_tags
(Optional[bool]
) \u2013 -
reload_on_file_change
(Optional[bool]
) \u2013 -
reload_on_template_change
(Optional[bool]
) \u2013 -
static_files_allowed
(Optional[List[Union[str, Pattern]]]
) \u2013 -
static_files_forbidden
(Optional[List[Union[str, Pattern]]]
) \u2013 -
tag_formatter
(Optional[Union[TagFormatterABC, str]]
) \u2013 -
template_cache_size
(Optional[int]
) \u2013
class-attribute
instance-attribute
","text":"app_dirs: Optional[Sequence[str]] = None\n
See source code
Specify the app-level directories that contain your components.
Defaults to
[\"components\"]
. That is, for each Django app, we search<app>/components/
for components.The paths must be relative to app, e.g.:
COMPONENTS = ComponentsSettings(\n app_dirs=[\"my_comps\"],\n)\n
To search for
<app>/my_comps/
.These locations are searched during autodiscovery, or when you define HTML, JS, or CSS as separate files.
Set to empty list to disable app-level components:
"},{"location":"reference/api/#django_components.ComponentsSettings.autodiscover","title":"autodiscoverCOMPONENTS = ComponentsSettings(\n app_dirs=[],\n)\n
class-attribute
instance-attribute
","text":"autodiscover: Optional[bool] = None\n
See source code
Toggle whether to run autodiscovery at the Django server startup.
Defaults to
True
"},{"location":"reference/api/#django_components.ComponentsSettings.cache","title":"cacheCOMPONENTS = ComponentsSettings(\n autodiscover=False,\n)\n
class-attribute
instance-attribute
","text":"cache: Optional[str] = None\n
See source code
Name of the Django cache to be used for storing component's JS and CSS files.
If
None
, aLocMemCache
is used with default settings.Defaults to
None
.Read more about caching.
"},{"location":"reference/api/#django_components.ComponentsSettings.context_behavior","title":"context_behaviorCOMPONENTS = ComponentsSettings(\n cache=\"my_cache\",\n)\n
class-attribute
instance-attribute
","text":"context_behavior: Optional[ContextBehaviorType] = None\n
See source code
Configure whether, inside a component template, you can use variables from the outside (
\"django\"
) or not (\"isolated\"
). This also affects what variables are available inside the{% fill %}
tags.Also see Component context and scope.
Defaults to
\"django\"
.COMPONENTS = ComponentsSettings(\n context_behavior=\"isolated\",\n)\n
NOTE:
context_behavior
andslot_context_behavior
options were merged in v0.70.If you are migrating from BEFORE v0.67, set
context_behavior
to\"django\"
. From v0.67 to v0.78 (incl) the default value was\"isolated\"
.For v0.79 and later, the default is again
"},{"location":"reference/api/#django_components.ComponentsSettings.debug_highlight_components","title":"debug_highlight_components\"django\"
. See the rationale for change here.class-attribute
instance-attribute
","text":"debug_highlight_components: Optional[bool] = None\n
See source code
Enable / disable component highlighting. See Troubleshooting for more details.
Defaults to
False
.
"},{"location":"reference/api/#django_components.ComponentsSettings.debug_highlight_slots","title":"debug_highlight_slotsCOMPONENTS = ComponentsSettings(\n debug_highlight_components=True,\n)\n
class-attribute
instance-attribute
","text":"debug_highlight_slots: Optional[bool] = None\n
See source code
Enable / disable slot highlighting. See Troubleshooting for more details.
Defaults to
False
.
"},{"location":"reference/api/#django_components.ComponentsSettings.dirs","title":"dirsCOMPONENTS = ComponentsSettings(\n debug_highlight_slots=True,\n)\n
class-attribute
instance-attribute
","text":"dirs: Optional[Sequence[Union[str, PathLike, Tuple[str, str], Tuple[str, PathLike]]]] = None\n
See source code
Specify the directories that contain your components.
Defaults to
[Path(settings.BASE_DIR) / \"components\"]
. That is, the rootcomponents/
app.Directories must be full paths, same as with STATICFILES_DIRS.
These locations are searched during autodiscovery, or when you define HTML, JS, or CSS as separate files.
COMPONENTS = ComponentsSettings(\n dirs=[BASE_DIR / \"components\"],\n)\n
Set to empty list to disable global components directories:
"},{"location":"reference/api/#django_components.ComponentsSettings.dynamic_component_name","title":"dynamic_component_nameCOMPONENTS = ComponentsSettings(\n dirs=[],\n)\n
class-attribute
instance-attribute
","text":"dynamic_component_name: Optional[str] = None\n
See source code
By default, the dynamic component is registered under the name
\"dynamic\"
.In case of a conflict, you can use this setting to change the component name used for the dynamic components.
# settings.py\nCOMPONENTS = ComponentsSettings(\n dynamic_component_name=\"my_dynamic\",\n)\n
After which you will be able to use the dynamic component with the new name:
"},{"location":"reference/api/#django_components.ComponentsSettings.forbidden_static_files","title":"forbidden_static_files{% component \"my_dynamic\" is=table_comp data=table_data headers=table_headers %}\n {% fill \"pagination\" %}\n {% component \"pagination\" / %}\n {% endfill %}\n{% endcomponent %}\n
class-attribute
instance-attribute
","text":"forbidden_static_files: Optional[List[Union[str, Pattern]]] = None\n
See source code
Deprecated. Use
"},{"location":"reference/api/#django_components.ComponentsSettings.libraries","title":"librariesCOMPONENTS.static_files_forbidden
instead.class-attribute
instance-attribute
","text":"libraries: Optional[List[str]] = None\n
See source code
Configure extra python modules that should be loaded.
This may be useful if you are not using the autodiscovery feature, or you need to load components from non-standard locations. Thus you can have a structure of components that is independent from your apps.
Expects a list of python module paths. Defaults to empty list.
Example:
COMPONENTS = ComponentsSettings(\n libraries=[\n \"mysite.components.forms\",\n \"mysite.components.buttons\",\n \"mysite.components.cards\",\n ],\n)\n
This would be the equivalent of importing these modules from within Django's
AppConfig.ready()
:
"},{"location":"reference/api/#django_components.ComponentsSettings.libraries--manually-loading-libraries","title":"Manually loading libraries","text":"class MyAppConfig(AppConfig):\n def ready(self):\n import \"mysite.components.forms\"\n import \"mysite.components.buttons\"\n import \"mysite.components.cards\"\n
In the rare case that you need to manually trigger the import of libraries, you can use the
import_libraries()
function:
"},{"location":"reference/api/#django_components.ComponentsSettings.multiline_tags","title":"multiline_tagsfrom django_components import import_libraries\n\nimport_libraries()\n
class-attribute
instance-attribute
","text":"multiline_tags: Optional[bool] = None\n
See source code
Enable / disable multiline support for template tags. If
True
, template tags like{% component %}
or{{ my_var }}
can span multiple lines.Defaults to
True
.Disable this setting if you are making custom modifications to Django's regular expression for parsing templates at
django.template.base.tag_re
.
"},{"location":"reference/api/#django_components.ComponentsSettings.reload_on_file_change","title":"reload_on_file_changeCOMPONENTS = ComponentsSettings(\n multiline_tags=False,\n)\n
class-attribute
instance-attribute
","text":"reload_on_file_change: Optional[bool] = None\n
See source code
This is relevant if you are using the project structure where HTML, JS, CSS and Python are in separate files and nested in a directory.
In this case you may notice that when you are running a development server, the server sometimes does not reload when you change component files.
Django's native live reload logic handles only Python files and HTML template files. It does NOT reload when other file types change or when template files are nested more than one level deep.
The setting
reload_on_file_change
fixes this, reloading the dev server even when your component's HTML, JS, or CSS changes.If
True
, django_components configures Django to reload when files insideCOMPONENTS.dirs
orCOMPONENTS.app_dirs
change.See Reload dev server on component file changes.
Defaults to
False
.Warning
This setting should be enabled only for the dev environment!
"},{"location":"reference/api/#django_components.ComponentsSettings.reload_on_template_change","title":"reload_on_template_changeclass-attribute
instance-attribute
","text":"reload_on_template_change: Optional[bool] = None\n
See source code
Deprecated. Use
"},{"location":"reference/api/#django_components.ComponentsSettings.static_files_allowed","title":"static_files_allowedCOMPONENTS.reload_on_file_change
instead.class-attribute
instance-attribute
","text":"static_files_allowed: Optional[List[Union[str, Pattern]]] = None\n
See source code
A list of file extensions (including the leading dot) that define which files within
COMPONENTS.dirs
orCOMPONENTS.app_dirs
are treated as static files.If a file is matched against any of the patterns, it's considered a static file. Such files are collected when running
collectstatic
, and can be accessed under the static file endpoint.You can also pass in compiled regexes (
re.Pattern
) for more advanced patterns.By default, JS, CSS, and common image and font file formats are considered static files:
COMPONENTS = ComponentsSettings(\n static_files_allowed=[\n \".css\",\n \".js\", \".jsx\", \".ts\", \".tsx\",\n # Images\n \".apng\", \".png\", \".avif\", \".gif\", \".jpg\",\n \".jpeg\", \".jfif\", \".pjpeg\", \".pjp\", \".svg\",\n \".webp\", \".bmp\", \".ico\", \".cur\", \".tif\", \".tiff\",\n # Fonts\n \".eot\", \".ttf\", \".woff\", \".otf\", \".svg\",\n ],\n)\n
Warning
Exposing your Python files can be a security vulnerability. See Security notes.
"},{"location":"reference/api/#django_components.ComponentsSettings.static_files_forbidden","title":"static_files_forbiddenclass-attribute
instance-attribute
","text":"static_files_forbidden: Optional[List[Union[str, Pattern]]] = None\n
See source code
A list of file extensions (including the leading dot) that define which files within
COMPONENTS.dirs
orCOMPONENTS.app_dirs
will NEVER be treated as static files.If a file is matched against any of the patterns, it will never be considered a static file, even if the file matches a pattern in
static_files_allowed
.Use this setting together with
static_files_allowed
for a fine control over what file types will be exposed.You can also pass in compiled regexes (
re.Pattern
) for more advanced patterns.By default, any HTML and Python are considered NOT static files:
COMPONENTS = ComponentsSettings(\n static_files_forbidden=[\n \".html\", \".django\", \".dj\", \".tpl\",\n # Python files\n \".py\", \".pyc\",\n ],\n)\n
Warning
Exposing your Python files can be a security vulnerability. See Security notes.
"},{"location":"reference/api/#django_components.ComponentsSettings.tag_formatter","title":"tag_formatterclass-attribute
instance-attribute
","text":"tag_formatter: Optional[Union[TagFormatterABC, str]] = None\n
See source code
Configure what syntax is used inside Django templates to render components. See the available tag formatters.
Defaults to
\"django_components.component_formatter\"
.Learn more about Customizing component tags with TagFormatter.
Can be set either as direct reference:
from django_components import component_formatter\n\nCOMPONENTS = ComponentsSettings(\n \"tag_formatter\": component_formatter\n)\n
Or as an import string;
COMPONENTS = ComponentsSettings(\n \"tag_formatter\": \"django_components.component_formatter\"\n)\n
Examples:
-
\"django_components.component_formatter\"
Set
COMPONENTS = ComponentsSettings(\n \"tag_formatter\": \"django_components.component_formatter\"\n)\n
To write components like this:
{% component \"button\" href=\"...\" %}\n Click me!\n{% endcomponent %}\n
-
django_components.component_shorthand_formatter
Set
COMPONENTS = ComponentsSettings(\n \"tag_formatter\": \"django_components.component_shorthand_formatter\"\n)\n
To write components like this:
{% button href=\"...\" %}\n Click me!\n{% endbutton %}\n
class-attribute
instance-attribute
","text":"template_cache_size: Optional[int] = None\n
See source code
Configure the maximum amount of Django templates to be cached.
Defaults to
128
.Each time a Django template is rendered, it is cached to a global in-memory cache (using Python's
lru_cache
decorator). This speeds up the next render of the component. As the same component is often used many times on the same page, these savings add up.By default the cache holds 128 component templates in memory, which should be enough for most sites. But if you have a lot of components, or if you are overriding
Component.get_template()
to render many dynamic templates, you can increase this number.COMPONENTS = ComponentsSettings(\n template_cache_size=256,\n)\n
To remove the cache limit altogether and cache everything, set
template_cache_size
toNone
.COMPONENTS = ComponentsSettings(\n template_cache_size=None,\n)\n
If you want to add templates to the cache yourself, you can use
cached_template()
:
"},{"location":"reference/api/#django_components.ContextBehavior","title":"ContextBehavior","text":"from django_components import cached_template\n\ncached_template(\"Variable: {{ variable }}\")\n\n# You can optionally specify Template class, and other Template inputs:\nclass MyTemplate(Template):\n pass\n\ncached_template(\n \"Variable: {{ variable }}\",\n template_cls=MyTemplate,\n name=...\n origin=...\n engine=...\n)\n
Bases:
str
,enum.Enum
See source code
Configure how (and whether) the context is passed to the component fills and what variables are available inside the
{% fill %}
tags.Also see Component context and scope.
Options:
django
: With this setting, component fills behave as usual Django tags.isolated
: This setting makes the component fills behave similar to Vue or React.
Attributes:
-
DJANGO
\u2013 -
ISOLATED
\u2013
class-attribute
instance-attribute
","text":"DJANGO = 'django'\n
See source code
With this setting, component fills behave as usual Django tags. That is, they enrich the context, and pass it along.
- Component fills use the context of the component they are within.
- Variables from
Component.get_context_data()
are available to the component fill.
Example:
Given this template
{% with cheese=\"feta\" %}\n {% component 'my_comp' %}\n {{ my_var }} # my_var\n {{ cheese }} # cheese\n {% endcomponent %}\n{% endwith %}\n
and this context returned from the
Component.get_context_data()
method{ \"my_var\": 123 }\n
Then if component \"my_comp\" defines context
{ \"my_var\": 456 }\n
Then this will render:
456 # my_var\nfeta # cheese\n
Because \"my_comp\" overrides the variable \"my_var\", so
{{ my_var }}
equals456
.And variable \"cheese\" will equal
"},{"location":"reference/api/#django_components.ContextBehavior.ISOLATED","title":"ISOLATEDfeta
, because the fill CAN access the current context.class-attribute
instance-attribute
","text":"ISOLATED = 'isolated'\n
See source code
This setting makes the component fills behave similar to Vue or React, where the fills use EXCLUSIVELY the context variables defined in
Component.get_context_data()
.Example:
Given this template
{% with cheese=\"feta\" %}\n {% component 'my_comp' %}\n {{ my_var }} # my_var\n {{ cheese }} # cheese\n {% endcomponent %}\n{% endwith %}\n
and this context returned from the
get_context_data()
method{ \"my_var\": 123 }\n
Then if component \"my_comp\" defines context
{ \"my_var\": 456 }\n
Then this will render:
123 # my_var\n # cheese\n
Because both variables \"my_var\" and \"cheese\" are taken from the root context. Since \"cheese\" is not defined in root context, it's empty.
"},{"location":"reference/api/#django_components.EmptyDict","title":"EmptyDict","text":"Bases:
dict
See source code
TypedDict with no members.
You can use this to define a Component that accepts NO kwargs, or NO slots, or returns NO data from
Component.get_context_data()
/Component.get_js_data()
/Component.get_css_data()
:Accepts NO kwargs:
from django_components import Component, EmptyDict\n\nclass Table(Component(Any, EmptyDict, Any, Any, Any, Any))\n ...\n
Accepts NO slots:
from django_components import Component, EmptyDict\n\nclass Table(Component(Any, Any, EmptyDict, Any, Any, Any))\n ...\n
Returns NO data from
get_context_data()
:from django_components import Component, EmptyDict\n\nclass Table(Component(Any, Any, Any, EmptyDict, Any, Any))\n ...\n
Going back to the example with NO kwargs, when you then call
Component.render()
orComponent.render_to_response()
, thekwargs
parameter will raise type error ifkwargs
is anything else than an empty dict.Table.render(\n kwargs: {},\n)\n
Omitting
kwargs
is also fine:Table.render()\n
Other values are not allowed. This will raise an error with MyPy:
"},{"location":"reference/api/#django_components.EmptyTuple","title":"EmptyTupleTable.render(\n kwargs: {\n \"one\": 2,\n \"three\": 4,\n },\n)\n
module-attribute
","text":"EmptyTuple = Tuple[]\n
See source code
Tuple with no members.
You can use this to define a Component that accepts NO positional arguments:
from django_components import Component, EmptyTuple\n\nclass Table(Component(EmptyTuple, Any, Any, Any, Any, Any))\n ...\n
After that, when you call
Component.render()
orComponent.render_to_response()
, theargs
parameter will raise type error ifargs
is anything else than an empty tuple.Table.render(\n args: (),\n)\n
Omitting
args
is also fine:Table.render()\n
Other values are not allowed. This will raise an error with MyPy:
"},{"location":"reference/api/#django_components.RegistrySettings","title":"RegistrySettings","text":"Table.render(\n args: (\"one\", 2, \"three\"),\n)\n
Bases:
tuple
See source code
Configuration for a
ComponentRegistry
.These settings define how the components registered with this registry will behave when rendered.
from django_components import ComponentRegistry, RegistrySettings\n\nregistry_settings = RegistrySettings(\n context_behavior=\"django\",\n tag_formatter=\"django_components.component_shorthand_formatter\",\n)\n\nregistry = ComponentRegistry(settings=registry_settings)\n
Attributes:
-
CONTEXT_BEHAVIOR
(Optional[ContextBehaviorType]
) \u2013 -
TAG_FORMATTER
(Optional[Union[TagFormatterABC, str]]
) \u2013 -
context_behavior
(Optional[ContextBehaviorType]
) \u2013 -
tag_formatter
(Optional[Union[TagFormatterABC, str]]
) \u2013
class-attribute
instance-attribute
","text":"CONTEXT_BEHAVIOR: Optional[ContextBehaviorType] = None\n
See source code
Deprecated. Use
context_behavior
instead. Will be removed in v1.Same as the global
COMPONENTS.context_behavior
setting, but for this registry.If omitted, defaults to the global
"},{"location":"reference/api/#django_components.RegistrySettings.TAG_FORMATTER","title":"TAG_FORMATTERCOMPONENTS.context_behavior
setting.class-attribute
instance-attribute
","text":"TAG_FORMATTER: Optional[Union[TagFormatterABC, str]] = None\n
See source code
Deprecated. Use
tag_formatter
instead. Will be removed in v1.Same as the global
COMPONENTS.tag_formatter
setting, but for this registry.If omitted, defaults to the global
"},{"location":"reference/api/#django_components.RegistrySettings.context_behavior","title":"context_behaviorCOMPONENTS.tag_formatter
setting.class-attribute
instance-attribute
","text":"context_behavior: Optional[ContextBehaviorType] = None\n
See source code
Same as the global
COMPONENTS.context_behavior
setting, but for this registry.If omitted, defaults to the global
"},{"location":"reference/api/#django_components.RegistrySettings.tag_formatter","title":"tag_formatterCOMPONENTS.context_behavior
setting.class-attribute
instance-attribute
","text":"tag_formatter: Optional[Union[TagFormatterABC, str]] = None\n
See source code
Same as the global
COMPONENTS.tag_formatter
setting, but for this registry.If omitted, defaults to the global
"},{"location":"reference/api/#django_components.Slot","title":"SlotCOMPONENTS.tag_formatter
setting.dataclass
","text":"Slot(\n content_func: SlotFunc[TSlotData],\n escaped: bool = False,\n component_name: Optional[str] = None,\n slot_name: Optional[str] = None,\n nodelist: Optional[NodeList] = None,\n)\n
Bases:
typing.Generic
See source code
This class holds the slot content function along with related metadata.
Attributes:
-
component_name
(Optional[str]
) \u2013 -
content_func
(SlotFunc[TSlotData]
) \u2013 -
do_not_call_in_templates
(bool
) \u2013 -
escaped
(bool
) \u2013 -
nodelist
(Optional[NodeList]
) \u2013 -
slot_name
(Optional[str]
) \u2013
class-attribute
instance-attribute
","text":"component_name: Optional[str] = None\n
See source code
Name of the component that originally defined or accepted this slot fill.
"},{"location":"reference/api/#django_components.Slot.content_func","title":"content_funcinstance-attribute
","text":"
"},{"location":"reference/api/#django_components.Slot.do_not_call_in_templates","title":"do_not_call_in_templatescontent_func: SlotFunc[TSlotData]\n
property
","text":"
"},{"location":"reference/api/#django_components.Slot.escaped","title":"escapeddo_not_call_in_templates: bool\n
class-attribute
instance-attribute
","text":"escaped: bool = False\n
See source code
Whether the slot content has been escaped.
"},{"location":"reference/api/#django_components.Slot.nodelist","title":"nodelistclass-attribute
instance-attribute
","text":"nodelist: Optional[NodeList] = None\n
See source code
Nodelist of the slot content.
"},{"location":"reference/api/#django_components.Slot.slot_name","title":"slot_nameclass-attribute
instance-attribute
","text":"slot_name: Optional[str] = None\n
See source code
Name of the slot that originally defined or accepted this slot fill.
"},{"location":"reference/api/#django_components.SlotContent","title":"SlotContentmodule-attribute
","text":"
"},{"location":"reference/api/#django_components.SlotFunc","title":"SlotFunc","text":""},{"location":"reference/api/#django_components.SlotRef","title":"SlotRef","text":"SlotContent = Union[SlotResult, SlotFunc[TSlotData], 'Slot[TSlotData]']\n
SlotRef(slot: SlotNode, context: Context)\n
Bases:
object
See source code
SlotRef allows to treat a slot as a variable. The slot is rendered only once the instance is coerced to string.
This is used to access slots as variables inside the templates. When a SlotRef is rendered in the template with
"},{"location":"reference/api/#django_components.SlotResult","title":"SlotResult{{ my_lazy_slot }}
, it will output the contents of the slot.module-attribute
","text":"
"},{"location":"reference/api/#django_components.TagFormatterABC","title":"TagFormatterABC","text":"SlotResult = Union[str, SafeString]\n
Bases:
abc.ABC
See source code
Abstract base class for defining custom tag formatters.
Tag formatters define how the component tags are used in the template.
Read more about Tag formatter.
For example, with the default tag formatter (
ComponentFormatter
), components are written as:{% component \"comp_name\" %}\n{% endcomponent %}\n
While with the shorthand tag formatter (
ShorthandComponentFormatter
), components are written as:{% comp_name %}\n{% endcomp_name %}\n
Example:
Implementation for
ShorthandComponentFormatter
:from djagno_components import TagFormatterABC, TagResult\n\nclass ShorthandComponentFormatter(TagFormatterABC):\n def start_tag(self, name: str) -> str:\n return name\n\n def end_tag(self, name: str) -> str:\n return f\"end{name}\"\n\n def parse(self, tokens: List[str]) -> TagResult:\n tokens = [*tokens]\n name = tokens.pop(0)\n return TagResult(name, tokens)\n
Methods:
-
end_tag
\u2013 -
parse
\u2013 -
start_tag
\u2013
abstractmethod
","text":"end_tag(name: str) -> str\n
See source code
Formats the end tag of a block component.
Parameters:
-
name
(str
) \u2013Component's registered name. Required.
Returns:
-
str
(str
) \u2013The formatted end tag.
abstractmethod
","text":"parse(tokens: List[str]) -> TagResult\n
See source code
Given the tokens (words) passed to a component start tag, this function extracts the component name from the tokens list, and returns
TagResult
, which is a tuple of(component_name, remaining_tokens)
.Parameters:
-
tokens
([List(str]
) \u2013List of tokens passed to the component tag.
Returns:
-
TagResult
(TagResult
) \u2013Parsed component name and remaining tokens.
Example:
Assuming we used a component in a template like this:
{% component \"my_comp\" key=val key2=val2 %}\n{% endcomponent %}\n
This function receives a list of tokens:
['component', '\"my_comp\"', 'key=val', 'key2=val2']\n
component
is the tag name, which we drop.\"my_comp\"
is the component name, but we must remove the extra quotes.- The remaining tokens we pass unmodified, as that's the input to the component.
So in the end, we return:
"},{"location":"reference/api/#django_components.TagFormatterABC.start_tag","title":"start_tagTagResult('my_comp', ['key=val', 'key2=val2'])\n
abstractmethod
","text":"start_tag(name: str) -> str\n
See source code
Formats the start tag of a component.
Parameters:
-
name
(str
) \u2013Component's registered name. Required.
Returns:
-
str
(str
) \u2013The formatted start tag.
Bases:
tuple
See source code
The return value from
TagFormatter.parse()
.Read more about Tag formatter.
Attributes:
-
component_name
(str
) \u2013 -
tokens
(List[str]
) \u2013
instance-attribute
","text":"component_name: str\n
See source code
Component name extracted from the template tag
For example, if we had tag
{% component \"my_comp\" key=val key2=val2 %}\n
Then
"},{"location":"reference/api/#django_components.TagResult.tokens","title":"tokenscomponent_name
would bemy_comp
.instance-attribute
","text":"tokens: List[str]\n
See source code
Remaining tokens (words) that were passed to the tag, with component name removed
For example, if we had tag
{% component \"my_comp\" key=val key2=val2 %}\n
Then
"},{"location":"reference/api/#django_components.autodiscover","title":"autodiscover","text":"tokens
would be['key=val', 'key2=val2']
.autodiscover(map_module: Optional[Callable[[str], str]] = None) -> List[str]\n
See source code
Search for all python files in
COMPONENTS.dirs
andCOMPONENTS.app_dirs
and import them.See Autodiscovery.
NOTE: Subdirectories and files starting with an underscore
_
(except for__init__.py
are ignored.Parameters:
-
map_module
(Callable[[str], str]
, default:None
) \u2013Map the module paths with
map_module
function. This serves as an escape hatch for when you need to use this function in tests.
Returns:
-
List[str]
\u2013List[str]: A list of module paths of imported files.
To get the same list of modules that
autodiscover()
would return, but without importing them, useget_component_files()
:
"},{"location":"reference/api/#django_components.cached_template","title":"cached_template","text":"from django_components import get_component_files\n\nmodules = get_component_files(\".py\")\n
cached_template(\n template_string: str,\n template_cls: Optional[Type[Template]] = None,\n origin: Optional[Origin] = None,\n name: Optional[str] = None,\n engine: Optional[Any] = None,\n) -> Template\n
See source code
Create a Template instance that will be cached as per the
COMPONENTS.template_cache_size
setting.Parameters:
-
template_string
(str
) \u2013Template as a string, same as the first argument to Django's
Template
. Required. -
template_cls
(Type[Template]
, default:None
) \u2013Specify the Template class that should be instantiated. Defaults to Django's
Template
class. -
origin
(Type[Origin]
, default:None
) \u2013Sets
Template.Origin
. -
name
(Type[str]
, default:None
) \u2013Sets
Template.name
-
engine
(Type[Any]
, default:None
) \u2013Sets
Template.engine
"},{"location":"reference/api/#django_components.get_component_dirs","title":"get_component_dirs","text":"from django_components import cached_template\n\ntemplate = cached_template(\"Variable: {{ variable }}\")\n\n# You can optionally specify Template class, and other Template inputs:\nclass MyTemplate(Template):\n pass\n\ntemplate = cached_template(\n \"Variable: {{ variable }}\",\n template_cls=MyTemplate,\n name=...\n origin=...\n engine=...\n)\n
get_component_dirs(include_apps: bool = True) -> List[Path]\n
See source code
Get directories that may contain component files.
This is the heart of all features that deal with filesystem and file lookup. Autodiscovery, Django template resolution, static file resolution - They all use this.
Parameters:
-
include_apps
(bool
, default:True
) \u2013Include directories from installed Django apps. Defaults to
True
.
Returns:
-
List[Path]
\u2013List[Path]: A list of directories that may contain component files.
get_component_dirs()
searches for dirs set inCOMPONENTS.dirs
settings. If none set, defaults to searching for a\"components\"
app.In addition to that, also all installed Django apps are checked whether they contain directories as set in
COMPONENTS.app_dirs
(e.g.[app]/components
).Notes:
-
Paths that do not point to directories are ignored.
-
BASE_DIR
setting is required. -
The paths in
COMPONENTS.dirs
must be absolute paths.
get_component_files(suffix: Optional[str] = None) -> List[ComponentFileEntry]\n
See source code
Search for files within the component directories (as defined in
get_component_dirs()
).Requires
BASE_DIR
setting to be set.Subdirectories and files starting with an underscore
_
(except__init__.py
) are ignored.Parameters:
-
suffix
(Optional[str]
, default:None
) \u2013The suffix to search for. E.g.
.py
,.js
,.css
. Defaults toNone
, which will search for all files.
Returns:
-
List[ComponentFileEntry]
\u2013List[ComponentFileEntry] A list of entries that contain both the filesystem path and the python import path (dot path).
Example:
"},{"location":"reference/api/#django_components.import_libraries","title":"import_libraries","text":"from django_components import get_component_files\n\nmodules = get_component_files(\".py\")\n
import_libraries(map_module: Optional[Callable[[str], str]] = None) -> List[str]\n
See source code
Import modules set in
COMPONENTS.libraries
setting.See Autodiscovery.
Parameters:
-
map_module
(Callable[[str], str]
, default:None
) \u2013Map the module paths with
map_module
function. This serves as an escape hatch for when you need to use this function in tests.
Returns:
-
List[str]
\u2013List[str]: A list of module paths of imported files.
Examples:
Normal usage - load libraries after Django has loaded
from django_components import import_libraries\n\nclass MyAppConfig(AppConfig):\n def ready(self):\n import_libraries()\n
Potential usage in tests
"},{"location":"reference/api/#django_components.register","title":"register","text":"from django_components import import_libraries\n\nimport_libraries(lambda path: path.replace(\"tests.\", \"myapp.\"))\n
register(name: str, registry: Optional[ComponentRegistry] = None) -> Callable[\n [Type[Component[ArgsType, KwargsType, SlotsType, DataType, JsDataType, CssDataType]]],\n Type[Component[ArgsType, KwargsType, SlotsType, DataType, JsDataType, CssDataType]],\n]\n
See source code
Class decorator for registering a component to a component registry.
See Registering components.
Parameters:
-
name
(str
) \u2013Registered name. This is the name by which the component will be accessed from within a template when using the
{% component %}
tag. Required. -
registry
(ComponentRegistry
, default:None
) \u2013Specify the registry to which to register this component. If omitted, component is registered to the default registry.
Raises:
-
AlreadyRegistered
\u2013If there is already a component registered under the same name.
Examples:
from django_components import Component, register\n\n@register(\"my_component\")\nclass MyComponent(Component):\n ...\n
Specifing
ComponentRegistry
the component should be registered to by setting theregistry
kwarg:
"},{"location":"reference/api/#django_components.registry","title":"registryfrom django.template import Library\nfrom django_components import Component, ComponentRegistry, register\n\nmy_lib = Library()\nmy_reg = ComponentRegistry(library=my_lib)\n\n@register(\"my_component\", registry=my_reg)\nclass MyComponent(Component):\n ...\n
module-attribute
","text":"registry: ComponentRegistry = ComponentRegistry()\n
See source code
The default and global component registry. Use this instance to directly register or remove components:
See Registering components.
"},{"location":"reference/api/#django_components.render_dependencies","title":"render_dependencies","text":"# Register components\nregistry.register(\"button\", ButtonComponent)\nregistry.register(\"card\", CardComponent)\n\n# Get single\nregistry.get(\"button\")\n\n# Get all\nregistry.all()\n\n# Unregister single\nregistry.unregister(\"button\")\n\n# Unregister all\nregistry.clear()\n
render_dependencies(content: TContent, type: RenderType = 'document') -> TContent\n
See source code
Given a string that contains parts that were rendered by components, this function inserts all used JS and CSS.
By default, the string is parsed as an HTML and: - CSS is inserted at the end of
<head>
(if present) - JS is inserted at the end of<body>
(if present)If you used
{% component_js_dependencies %}
or{% component_css_dependencies %}
, then the JS and CSS will be inserted only at these locations.Example:
"},{"location":"reference/api/#django_components.template_tag","title":"template_tag","text":"def my_view(request):\n template = Template('''\n {% load components %}\n <!doctype html>\n <html>\n <head></head>\n <body>\n <h1>{{ table_name }}</h1>\n {% component \"table\" name=table_name / %}\n </body>\n </html>\n ''')\n\n html = template.render(\n Context({\n \"table_name\": request.GET[\"name\"],\n })\n )\n\n # This inserts components' JS and CSS\n processed_html = render_dependencies(html)\n\n return HttpResponse(processed_html)\n
template_tag(\n library: Library, tag: str, end_tag: Optional[str] = None, allowed_flags: Optional[List[str]] = None\n) -> Callable[[Callable], Callable]\n
See source code
A simplified version of creating a template tag based on
BaseNode
.Instead of defining the whole class, you can just define the
render()
method.from django.template import Context, Library\nfrom django_components import BaseNode, template_tag\n\nlibrary = Library()\n\n@template_tag(\n library,\n tag=\"mytag\",\n end_tag=\"endmytag\",\n allowed_flags=[\"required\"],\n)\ndef mytag(node: BaseNode, context: Context, name: str, **kwargs: Any) -> str:\n return f\"Hello, {name}!\"\n
This will allow the template tag
{% mytag %}
to be used like this:{% mytag name=\"John\" %}\n{% mytag name=\"John\" required %} ... {% endmytag %}\n
The given function will be wrapped in a class that inherits from
BaseNode
.And this class will be registered with the given library.
The function MUST accept at least two positional arguments:
node
andcontext
node
is theBaseNode
instance.context
is theContext
of the template.
Any extra parameters defined on this function will be part of the tag's input parameters.
For more info, see
"},{"location":"reference/commands/","title":"Commands","text":""},{"location":"reference/commands/#commands","title":"Commands","text":"BaseNode.render()
.These are all the Django management commands that will be added by installing
"},{"location":"reference/commands/#startcomponent","title":"django_components
:startcomponent
","text":"usage: manage.py startcomponent [-h] [--path PATH] [--js JS] [--css CSS]\n [--template TEMPLATE] [--force] [--verbose]\n [--dry-run] [--version] [-v {0,1,2,3}]\n [--settings SETTINGS]\n [--pythonpath PYTHONPATH] [--traceback]\n [--no-color] [--force-color] [--skip-checks]\n name\n
See source code
Create a new django component.
Positional Arguments:
name
- The name of the component to create. This is a required argument.
Options:
-h
,--help
- show this help message and exit
--path PATH
- The path to the component's directory. This is an optional argument. If not provided, the command will use the
COMPONENTS.dirs
setting from your Django settings.
- The path to the component's directory. This is an optional argument. If not provided, the command will use the
--js JS
- The name of the JavaScript file. This is an optional argument. The default value is
script.js
.
- The name of the JavaScript file. This is an optional argument. The default value is
--css CSS
- The name of the CSS file. This is an optional argument. The default value is
style.css
.
- The name of the CSS file. This is an optional argument. The default value is
--template TEMPLATE
- The name of the template file. This is an optional argument. The default value is
template.html
.
- The name of the template file. This is an optional argument. The default value is
--force
- This option allows you to overwrite existing files if they exist. This is an optional argument.
--verbose
- This option allows the command to print additional information during component creation. This is an optional argument.
--dry-run
- This option allows you to simulate component creation without actually creating any files. This is an optional argument. The default value is
False
.
- This option allows you to simulate component creation without actually creating any files. This is an optional argument. The default value is
--version
- Show program's version number and exit.
-v {0,1,2,3}
,--verbosity {0,1,2,3}
- Verbosity level; 0=minimal output, 1=normal output, 2=verbose output, 3=very verbose output
--settings SETTINGS
- The Python path to a settings module, e.g. \"myproject.settings.main\". If this isn't provided, the DJANGO_SETTINGS_MODULE environment variable will be used.
--pythonpath PYTHONPATH
- A directory to add to the Python path, e.g. \"/home/djangoprojects/myproject\".
--traceback
- Raise on CommandError exceptions.
--no-color
- Don't colorize the command output.
--force-color
- Force colorization of the command output.
--skip-checks
- Skip system checks.
To use the command, run the following command in your terminal:
python manage.py startcomponent <name> --path <path> --js <js_filename> --css <css_filename> --template <template_filename> --force --verbose --dry-run\n
Replace
"},{"location":"reference/commands/#management-command-examples","title":"Management Command Examples","text":"<name>
,<path>
,<js_filename>
,<css_filename>
, and<template_filename>
with your desired values.Here are some examples of how you can use the command:
"},{"location":"reference/commands/#creating-a-component-with-default-settings","title":"Creating a Component with Default Settings","text":"To create a component with the default settings, you only need to provide the name of the component:
python manage.py startcomponent my_component\n
This will create a new component named
"},{"location":"reference/commands/#creating-a-component-with-custom-settings","title":"Creating a Component with Custom Settings","text":"my_component
in thecomponents
directory of your Django project. The JavaScript, CSS, and template files will be namedscript.js
,style.css
, andtemplate.html
, respectively.You can also create a component with custom settings by providing additional arguments:
python manage.py startcomponent new_component --path my_components --js my_script.js --css my_style.css --template my_template.html\n
This will create a new component named
"},{"location":"reference/commands/#overwriting-an-existing-component","title":"Overwriting an Existing Component","text":"new_component
in themy_components
directory. The JavaScript, CSS, and template files will be namedmy_script.js
,my_style.css
, andmy_template.html
, respectively.If you want to overwrite an existing component, you can use the
--force
option:python manage.py startcomponent my_component --force\n
This will overwrite the existing
"},{"location":"reference/commands/#simulating-component-creation","title":"Simulating Component Creation","text":"my_component
if it exists.If you want to simulate the creation of a component without actually creating any files, you can use the
--dry-run
option:python manage.py startcomponent my_component --dry-run\n
This will simulate the creation of
"},{"location":"reference/commands/#upgradecomponent","title":"my_component
without creating any files.upgradecomponent
","text":"usage: manage.py upgradecomponent [-h] [--path PATH] [--version]\n [-v {0,1,2,3}] [--settings SETTINGS]\n [--pythonpath PYTHONPATH] [--traceback]\n [--no-color] [--force-color] [--skip-checks]\n
See source code
Updates component and component_block tags to the new syntax
Options:
-h
,--help
- show this help message and exit
--path PATH
- Path to search for components
--version
- Show program's version number and exit.
-v {0,1,2,3}
,--verbosity {0,1,2,3}
- Verbosity level; 0=minimal output, 1=normal output, 2=verbose output, 3=very verbose output
--settings SETTINGS
- The Python path to a settings module, e.g. \"myproject.settings.main\". If this isn't provided, the DJANGO_SETTINGS_MODULE environment variable will be used.
--pythonpath PYTHONPATH
- A directory to add to the Python path, e.g. \"/home/djangoprojects/myproject\".
--traceback
- Raise on CommandError exceptions.
--no-color
- Don't colorize the command output.
--force-color
- Force colorization of the command output.
--skip-checks
- Skip system checks.
These are the components provided by django_components.
"},{"location":"reference/components/#django_components.components.dynamic.DynamicComponent","title":"DynamicComponent
","text":"Bases:
django_components.component.Component
See source code
This component is given a registered name or a reference to another component, and behaves as if the other component was in its place.
The args, kwargs, and slot fills are all passed down to the underlying component.
Parameters:
-
is
(str | Type[Component]
) \u2013Component that should be rendered. Either a registered name of a component, or a Component class directly. Required.
-
registry
(ComponentRegistry
, default:None
) \u2013Specify the registry to search for the registered name. If omitted, all registries are searched until the first match.
-
*args
\u2013Additional data passed to the component.
-
**kwargs
\u2013Additional data passed to the component.
Slots:
- Any slots, depending on the actual component.
Examples:
Django
{% component \"dynamic\" is=table_comp data=table_data headers=table_headers %}\n {% fill \"pagination\" %}\n {% component \"pagination\" / %}\n {% endfill %}\n{% endcomponent %}\n
Or in case you use the
django_components.component_shorthand_formatter
tag formatter:{% dynamic is=table_comp data=table_data headers=table_headers %}\n {% fill \"pagination\" %}\n {% component \"pagination\" / %}\n {% endfill %}\n{% enddynamic %}\n
Python
"},{"location":"reference/components/#django_components.components.dynamic.DynamicComponent--use-cases","title":"Use cases","text":"from django_components import DynamicComponent\n\nDynamicComponent.render(\n kwargs={\n \"is\": table_comp,\n \"data\": table_data,\n \"headers\": table_headers,\n },\n slots={\n \"pagination\": PaginationComponent.render(\n render_dependencies=False,\n ),\n },\n)\n
Dynamic components are suitable if you are writing something like a form component. You may design it such that users give you a list of input types, and you render components depending on the input types.
While you could handle this with a series of if / else statements, that's not an extensible approach. Instead, you can use the dynamic component in place of normal components.
"},{"location":"reference/components/#django_components.components.dynamic.DynamicComponent--component-name","title":"Component name","text":"By default, the dynamic component is registered under the name
\"dynamic\"
. In case of a conflict, you can set theCOMPONENTS.dynamic_component_name
setting to change the name used for the dynamic components.# settings.py\nCOMPONENTS = ComponentsSettings(\n dynamic_component_name=\"my_dynamic\",\n)\n
After which you will be able to use the dynamic component with the new name:
"},{"location":"reference/exceptions/","title":"Exceptions","text":""},{"location":"reference/exceptions/#exceptions","title":"Exceptions","text":""},{"location":"reference/exceptions/#django_components.AlreadyRegistered","title":"AlreadyRegistered","text":"{% component \"my_dynamic\" is=table_comp data=table_data headers=table_headers %}\n {% fill \"pagination\" %}\n {% component \"pagination\" / %}\n {% endfill %}\n{% endcomponent %}\n
Bases:
Exception
See source code
Raised when you try to register a Component, but it's already registered with given ComponentRegistry.
"},{"location":"reference/exceptions/#django_components.NotRegistered","title":"NotRegistered","text":"Bases:
Exception
See source code
Raised when you try to access a Component, but it's NOT registered with given ComponentRegistry.
"},{"location":"reference/exceptions/#django_components.TagProtectedError","title":"TagProtectedError","text":"Bases:
Exception
See source code
The way the
TagFormatter
works is that, based on which start and end tags are used for rendering components, theComponentRegistry
behind the scenes un-/registers the template tags with the associated instance of Django'sLibrary
.In other words, if I have registered a component
\"table\"
, and I use the shorthand syntax:{% table ... %}\n{% endtable %}\n
Then
ComponentRegistry
registers the tagtable
onto the Django's Library instance.However, that means that if we registered a component
\"slot\"
, then we would overwrite the{% slot %}
tag from django_components.Thus, this exception is raised when a component is attempted to be registered under a forbidden name, such that it would overwrite one of django_component's own template tags.
"},{"location":"reference/middlewares/","title":"Middlewares","text":""},{"location":"reference/middlewares/#middlewares","title":"Middlewares","text":""},{"location":"reference/middlewares/#django_components.dependencies.ComponentDependencyMiddleware","title":"ComponentDependencyMiddleware
","text":"Bases:
object
See source code
Middleware that inserts CSS/JS dependencies for all rendered components at points marked with template tags.
"},{"location":"reference/settings/","title":"Settings","text":""},{"location":"reference/settings/#settings","title":"Settings","text":"You can configure django_components with a global
COMPONENTS
variable in your Django settings file, e.g.settings.py
. By default you don't need it set, there are resonable defaults.To configure the settings you can instantiate
ComponentsSettings
for validation and type hints. Or, for backwards compatibility, you can also use plain dictionary:
"},{"location":"reference/settings/#settings-defaults","title":"Settings defaults","text":"# settings.py\nfrom django_components import ComponentsSettings\n\nCOMPONENTS = ComponentsSettings(\n autodiscover=True,\n ...\n)\n\n# or\n\nCOMPONENTS = {\n \"autodiscover\": True,\n ...\n}\n
Here's overview of all available settings and their defaults:
"},{"location":"reference/settings/#django_components.app_settings.ComponentsSettings.app_dirs","title":"app_dirs","text":"defaults = ComponentsSettings(\n autodiscover=True,\n cache=None,\n context_behavior=ContextBehavior.DJANGO.value, # \"django\" | \"isolated\"\n # Root-level \"components\" dirs, e.g. `/path/to/proj/components/`\n dirs=[Path(settings.BASE_DIR) / \"components\"],\n # App-level \"components\" dirs, e.g. `[app]/components/`\n app_dirs=[\"components\"],\n debug_highlight_components=False,\n debug_highlight_slots=False,\n dynamic_component_name=\"dynamic\",\n libraries=[], # E.g. [\"mysite.components.forms\", ...]\n multiline_tags=True,\n reload_on_file_change=False,\n static_files_allowed=[\n \".css\",\n \".js\", \".jsx\", \".ts\", \".tsx\",\n # Images\n \".apng\", \".png\", \".avif\", \".gif\", \".jpg\",\n \".jpeg\", \".jfif\", \".pjpeg\", \".pjp\", \".svg\",\n \".webp\", \".bmp\", \".ico\", \".cur\", \".tif\", \".tiff\",\n # Fonts\n \".eot\", \".ttf\", \".woff\", \".otf\", \".svg\",\n ],\n static_files_forbidden=[\n # See https://marketplace.visualstudio.com/items?itemName=junstyle.vscode-django-support\n \".html\", \".django\", \".dj\", \".tpl\",\n # Python files\n \".py\", \".pyc\",\n ],\n tag_formatter=\"django_components.component_formatter\",\n template_cache_size=128,\n)\n
app_dirs: Optional[Sequence[str]] = None\n
See source code
Specify the app-level directories that contain your components.
Defaults to
[\"components\"]
. That is, for each Django app, we search<app>/components/
for components.The paths must be relative to app, e.g.:
COMPONENTS = ComponentsSettings(\n app_dirs=[\"my_comps\"],\n)\n
To search for
<app>/my_comps/
.These locations are searched during autodiscovery, or when you define HTML, JS, or CSS as separate files.
Set to empty list to disable app-level components:
"},{"location":"reference/settings/#django_components.app_settings.ComponentsSettings.autodiscover","title":"autodiscover","text":"COMPONENTS = ComponentsSettings(\n app_dirs=[],\n)\n
autodiscover: Optional[bool] = None\n
See source code
Toggle whether to run autodiscovery at the Django server startup.
Defaults to
True
"},{"location":"reference/settings/#django_components.app_settings.ComponentsSettings.cache","title":"cache","text":"COMPONENTS = ComponentsSettings(\n autodiscover=False,\n)\n
cache: Optional[str] = None\n
See source code
Name of the Django cache to be used for storing component's JS and CSS files.
If
None
, aLocMemCache
is used with default settings.Defaults to
None
.Read more about caching.
"},{"location":"reference/settings/#django_components.app_settings.ComponentsSettings.context_behavior","title":"context_behavior","text":"COMPONENTS = ComponentsSettings(\n cache=\"my_cache\",\n)\n
context_behavior: Optional[ContextBehaviorType] = None\n
See source code
Configure whether, inside a component template, you can use variables from the outside (
\"django\"
) or not (\"isolated\"
). This also affects what variables are available inside the{% fill %}
tags.Also see Component context and scope.
Defaults to
\"django\"
.COMPONENTS = ComponentsSettings(\n context_behavior=\"isolated\",\n)\n
NOTE:
context_behavior
andslot_context_behavior
options were merged in v0.70.If you are migrating from BEFORE v0.67, set
context_behavior
to\"django\"
. From v0.67 to v0.78 (incl) the default value was\"isolated\"
.For v0.79 and later, the default is again
"},{"location":"reference/settings/#django_components.app_settings.ComponentsSettings.debug_highlight_components","title":"debug_highlight_components","text":"\"django\"
. See the rationale for change here.debug_highlight_components: Optional[bool] = None\n
See source code
Enable / disable component highlighting. See Troubleshooting for more details.
Defaults to
False
.
"},{"location":"reference/settings/#django_components.app_settings.ComponentsSettings.debug_highlight_slots","title":"debug_highlight_slots","text":"COMPONENTS = ComponentsSettings(\n debug_highlight_components=True,\n)\n
debug_highlight_slots: Optional[bool] = None\n
See source code
Enable / disable slot highlighting. See Troubleshooting for more details.
Defaults to
False
.
"},{"location":"reference/settings/#django_components.app_settings.ComponentsSettings.dirs","title":"dirs","text":"COMPONENTS = ComponentsSettings(\n debug_highlight_slots=True,\n)\n
dirs: Optional[Sequence[Union[str, PathLike, Tuple[str, str], Tuple[str, PathLike]]]] = None\n
See source code
Specify the directories that contain your components.
Defaults to
[Path(settings.BASE_DIR) / \"components\"]
. That is, the rootcomponents/
app.Directories must be full paths, same as with STATICFILES_DIRS.
These locations are searched during autodiscovery, or when you define HTML, JS, or CSS as separate files.
COMPONENTS = ComponentsSettings(\n dirs=[BASE_DIR / \"components\"],\n)\n
Set to empty list to disable global components directories:
"},{"location":"reference/settings/#django_components.app_settings.ComponentsSettings.dynamic_component_name","title":"dynamic_component_name","text":"COMPONENTS = ComponentsSettings(\n dirs=[],\n)\n
dynamic_component_name: Optional[str] = None\n
See source code
By default, the dynamic component is registered under the name
\"dynamic\"
.In case of a conflict, you can use this setting to change the component name used for the dynamic components.
# settings.py\nCOMPONENTS = ComponentsSettings(\n dynamic_component_name=\"my_dynamic\",\n)\n
After which you will be able to use the dynamic component with the new name:
"},{"location":"reference/settings/#django_components.app_settings.ComponentsSettings.forbidden_static_files","title":"forbidden_static_files","text":"{% component \"my_dynamic\" is=table_comp data=table_data headers=table_headers %}\n {% fill \"pagination\" %}\n {% component \"pagination\" / %}\n {% endfill %}\n{% endcomponent %}\n
forbidden_static_files: Optional[List[Union[str, Pattern]]] = None\n
See source code
Deprecated. Use
"},{"location":"reference/settings/#django_components.app_settings.ComponentsSettings.libraries","title":"libraries","text":"COMPONENTS.static_files_forbidden
instead.libraries: Optional[List[str]] = None\n
See source code
Configure extra python modules that should be loaded.
This may be useful if you are not using the autodiscovery feature, or you need to load components from non-standard locations. Thus you can have a structure of components that is independent from your apps.
Expects a list of python module paths. Defaults to empty list.
Example:
COMPONENTS = ComponentsSettings(\n libraries=[\n \"mysite.components.forms\",\n \"mysite.components.buttons\",\n \"mysite.components.cards\",\n ],\n)\n
This would be the equivalent of importing these modules from within Django's
AppConfig.ready()
:
"},{"location":"reference/settings/#django_components.app_settings.ComponentsSettings.libraries--manually-loading-libraries","title":"Manually loading libraries","text":"class MyAppConfig(AppConfig):\n def ready(self):\n import \"mysite.components.forms\"\n import \"mysite.components.buttons\"\n import \"mysite.components.cards\"\n
In the rare case that you need to manually trigger the import of libraries, you can use the
import_libraries()
function:
"},{"location":"reference/settings/#django_components.app_settings.ComponentsSettings.multiline_tags","title":"multiline_tags","text":"from django_components import import_libraries\n\nimport_libraries()\n
multiline_tags: Optional[bool] = None\n
See source code
Enable / disable multiline support for template tags. If
True
, template tags like{% component %}
or{{ my_var }}
can span multiple lines.Defaults to
True
.Disable this setting if you are making custom modifications to Django's regular expression for parsing templates at
django.template.base.tag_re
.
"},{"location":"reference/settings/#django_components.app_settings.ComponentsSettings.reload_on_file_change","title":"reload_on_file_change","text":"COMPONENTS = ComponentsSettings(\n multiline_tags=False,\n)\n
reload_on_file_change: Optional[bool] = None\n
See source code
This is relevant if you are using the project structure where HTML, JS, CSS and Python are in separate files and nested in a directory.
In this case you may notice that when you are running a development server, the server sometimes does not reload when you change component files.
Django's native live reload logic handles only Python files and HTML template files. It does NOT reload when other file types change or when template files are nested more than one level deep.
The setting
reload_on_file_change
fixes this, reloading the dev server even when your component's HTML, JS, or CSS changes.If
True
, django_components configures Django to reload when files insideCOMPONENTS.dirs
orCOMPONENTS.app_dirs
change.See Reload dev server on component file changes.
Defaults to
False
.Warning
This setting should be enabled only for the dev environment!
"},{"location":"reference/settings/#django_components.app_settings.ComponentsSettings.reload_on_template_change","title":"reload_on_template_change","text":"reload_on_template_change: Optional[bool] = None\n
See source code
Deprecated. Use
"},{"location":"reference/settings/#django_components.app_settings.ComponentsSettings.static_files_allowed","title":"static_files_allowed","text":"COMPONENTS.reload_on_file_change
instead.static_files_allowed: Optional[List[Union[str, Pattern]]] = None\n
See source code
A list of file extensions (including the leading dot) that define which files within
COMPONENTS.dirs
orCOMPONENTS.app_dirs
are treated as static files.If a file is matched against any of the patterns, it's considered a static file. Such files are collected when running
collectstatic
, and can be accessed under the static file endpoint.You can also pass in compiled regexes (
re.Pattern
) for more advanced patterns.By default, JS, CSS, and common image and font file formats are considered static files:
COMPONENTS = ComponentsSettings(\n static_files_allowed=[\n \".css\",\n \".js\", \".jsx\", \".ts\", \".tsx\",\n # Images\n \".apng\", \".png\", \".avif\", \".gif\", \".jpg\",\n \".jpeg\", \".jfif\", \".pjpeg\", \".pjp\", \".svg\",\n \".webp\", \".bmp\", \".ico\", \".cur\", \".tif\", \".tiff\",\n # Fonts\n \".eot\", \".ttf\", \".woff\", \".otf\", \".svg\",\n ],\n)\n
Warning
Exposing your Python files can be a security vulnerability. See Security notes.
"},{"location":"reference/settings/#django_components.app_settings.ComponentsSettings.static_files_forbidden","title":"static_files_forbidden","text":"static_files_forbidden: Optional[List[Union[str, Pattern]]] = None\n
See source code
A list of file extensions (including the leading dot) that define which files within
COMPONENTS.dirs
orCOMPONENTS.app_dirs
will NEVER be treated as static files.If a file is matched against any of the patterns, it will never be considered a static file, even if the file matches a pattern in
static_files_allowed
.Use this setting together with
static_files_allowed
for a fine control over what file types will be exposed.You can also pass in compiled regexes (
re.Pattern
) for more advanced patterns.By default, any HTML and Python are considered NOT static files:
COMPONENTS = ComponentsSettings(\n static_files_forbidden=[\n \".html\", \".django\", \".dj\", \".tpl\",\n # Python files\n \".py\", \".pyc\",\n ],\n)\n
Warning
Exposing your Python files can be a security vulnerability. See Security notes.
"},{"location":"reference/settings/#django_components.app_settings.ComponentsSettings.tag_formatter","title":"tag_formatter","text":"tag_formatter: Optional[Union[TagFormatterABC, str]] = None\n
See source code
Configure what syntax is used inside Django templates to render components. See the available tag formatters.
Defaults to
\"django_components.component_formatter\"
.Learn more about Customizing component tags with TagFormatter.
Can be set either as direct reference:
from django_components import component_formatter\n\nCOMPONENTS = ComponentsSettings(\n \"tag_formatter\": component_formatter\n)\n
Or as an import string;
COMPONENTS = ComponentsSettings(\n \"tag_formatter\": \"django_components.component_formatter\"\n)\n
Examples:
-
\"django_components.component_formatter\"
Set
COMPONENTS = ComponentsSettings(\n \"tag_formatter\": \"django_components.component_formatter\"\n)\n
To write components like this:
{% component \"button\" href=\"...\" %}\n Click me!\n{% endcomponent %}\n
-
django_components.component_shorthand_formatter
Set
COMPONENTS = ComponentsSettings(\n \"tag_formatter\": \"django_components.component_shorthand_formatter\"\n)\n
To write components like this:
{% button href=\"...\" %}\n Click me!\n{% endbutton %}\n
template_cache_size: Optional[int] = None\n
See source code
Configure the maximum amount of Django templates to be cached.
Defaults to
128
.Each time a Django template is rendered, it is cached to a global in-memory cache (using Python's
lru_cache
decorator). This speeds up the next render of the component. As the same component is often used many times on the same page, these savings add up.By default the cache holds 128 component templates in memory, which should be enough for most sites. But if you have a lot of components, or if you are overriding
Component.get_template()
to render many dynamic templates, you can increase this number.COMPONENTS = ComponentsSettings(\n template_cache_size=256,\n)\n
To remove the cache limit altogether and cache everything, set
template_cache_size
toNone
.COMPONENTS = ComponentsSettings(\n template_cache_size=None,\n)\n
If you want to add templates to the cache yourself, you can use
cached_template()
:
"},{"location":"reference/signals/","title":"Signals","text":""},{"location":"reference/signals/#signals","title":"Signals","text":"from django_components import cached_template\n\ncached_template(\"Variable: {{ variable }}\")\n\n# You can optionally specify Template class, and other Template inputs:\nclass MyTemplate(Template):\n pass\n\ncached_template(\n \"Variable: {{ variable }}\",\n template_cls=MyTemplate,\n name=...\n origin=...\n engine=...\n)\n
Below are the signals that are sent by or during the use of django-components.
"},{"location":"reference/signals/#template_rendered","title":"template_rendered","text":"Django's
template_rendered
signal. This signal is sent when a template is rendered.Django-components triggers this signal when a component is rendered. If there are nested components, the signal is triggered for each component.
Import from django as
django.test.signals.template_rendered
.
"},{"location":"reference/tag_formatters/","title":"Tag formatters","text":""},{"location":"reference/tag_formatters/#tag-formatters","title":"Tag Formatters","text":"from django.test.signals import template_rendered\n\n# Setup a callback function\ndef my_callback(sender, **kwargs):\n ...\n\ntemplate_rendered.connect(my_callback)\n\nclass MyTable(Component):\n template = \"\"\"\n <table>\n <tr>\n <th>Header</th>\n </tr>\n <tr>\n <td>Cell</td>\n </tr>\n \"\"\"\n\n# This will trigger the signal\nMyTable().render()\n
Tag formatters allow you to change the syntax for calling components from within the Django templates.
Tag formatter are set via the tag_formatter setting.
"},{"location":"reference/tag_formatters/#available-tag-formatters","title":"Available tag formatters","text":"-
django_components.component_formatter
for ComponentFormatter -
django_components.component_shorthand_formatter
for ShorthandComponentFormatter
ComponentFormatter
","text":"Bases:
django_components.tag_formatter.TagFormatterABC
See source code
The original django_component's component tag formatter, it uses the
{% component %}
and{% endcomponent %}
tags, and the component name is given as the first positional arg.Example as block:
{% component \"mycomp\" abc=123 %}\n {% fill \"myfill\" %}\n ...\n {% endfill %}\n{% endcomponent %}\n
Example as inlined tag:
"},{"location":"reference/tag_formatters/#django_components.tag_formatter.ShorthandComponentFormatter","title":"{% component \"mycomp\" abc=123 / %}\n
ShorthandComponentFormatter
","text":"Bases:
django_components.tag_formatter.TagFormatterABC
See source code
The component tag formatter that uses
{% <name> %}
/{% end<name> %}
tags.This is similar to django-web-components and django-slippers syntax.
Example as block:
{% mycomp abc=123 %}\n {% fill \"myfill\" %}\n ...\n {% endfill %}\n{% endmycomp %}\n
Example as inlined tag:
"},{"location":"reference/template_tags/","title":"Template tags","text":""},{"location":"reference/template_tags/#template-tags","title":"Template tags","text":"{% mycomp abc=123 / %}\n
All following template tags are defined in
django_components.templatetags.component_tags
Import as
"},{"location":"reference/template_tags/#component_css_dependencies","title":"component_css_dependencies","text":"{% load component_tags %}\n
{% component_css_dependencies %}\n
See source code
Marks location where CSS link tags should be rendered after the whole HTML has been generated.
Generally, this should be inserted into the
<head>
tag of the HTML.If the generated HTML does NOT contain any
{% component_css_dependencies %}
tags, CSS links are by default inserted into the<head>
tag of the HTML. (See JS and CSS output locations)Note that there should be only one
"},{"location":"reference/template_tags/#component_js_dependencies","title":"component_js_dependencies","text":"{% component_css_dependencies %}
for the whole HTML document. If you insert this tag multiple times, ALL CSS links will be duplicately inserted into ALL these places.{% component_js_dependencies %}\n
See source code
Marks location where JS link tags should be rendered after the whole HTML has been generated.
Generally, this should be inserted at the end of the
<body>
tag of the HTML.If the generated HTML does NOT contain any
{% component_js_dependencies %}
tags, JS scripts are by default inserted at the end of the<body>
tag of the HTML. (See JS and CSS output locations)Note that there should be only one
"},{"location":"reference/template_tags/#component","title":"component","text":"{% component_js_dependencies %}
for the whole HTML document. If you insert this tag multiple times, ALL JS scripts will be duplicately inserted into ALL these places.{% component *args: Any, **kwargs: Any [only] %}\n{% endcomponent %}\n
See source code
Renders one of the components that was previously registered with
@register()
decorator.Args:
name
(str, required): Registered name of the component to render- All other args and kwargs are defined based on the component itself.
If you defined a component
\"my_table\"
from django_component import Component, register\n\n@register(\"my_table\")\nclass MyTable(Component):\n template = \"\"\"\n <table>\n <thead>\n {% for header in headers %}\n <th>{{ header }}</th>\n {% endfor %}\n </thead>\n <tbody>\n {% for row in rows %}\n <tr>\n {% for cell in row %}\n <td>{{ cell }}</td>\n {% endfor %}\n </tr>\n {% endfor %}\n <tbody>\n </table>\n \"\"\"\n\n def get_context_data(self, rows: List, headers: List):\n return {\n \"rows\": rows,\n \"headers\": headers,\n }\n
Then you can render this component by referring to
MyTable
via its registered name\"my_table\"
:
"},{"location":"reference/template_tags/#component-input","title":"Component input","text":"{% component \"my_table\" rows=rows headers=headers ... / %}\n
Positional and keyword arguments can be literals or template variables.
The component name must be a single- or double-quotes string and must be either:
-
The first positional argument after
component
:{% component \"my_table\" rows=rows headers=headers ... / %}\n
-
Passed as kwarg
name
:{% component rows=rows headers=headers name=\"my_table\" ... / %}\n
If the component defined any slots, you can pass in the content to be placed inside those slots by inserting
{% fill %}
tags, directly within the{% component %}
tag:
"},{"location":"reference/template_tags/#isolating-components","title":"Isolating components","text":"{% component \"my_table\" rows=rows headers=headers ... / %}\n {% fill \"pagination\" %}\n < 1 | 2 | 3 >\n {% endfill %}\n{% endcomponent %}\n
By default, components behave similarly to Django's
{% include %}
, and the template inside the component has access to the variables defined in the outer template.You can selectively isolate a component, using the
only
flag, so that the inner template can access only the data that was explicitly passed to it:
"},{"location":"reference/template_tags/#fill","title":"fill","text":"{% component \"name\" positional_arg keyword_arg=value ... only %}\n
{% fill name: str, *, data: Optional[str] = None, default: Optional[str] = None %}\n{% endfill %}\n
See source code
Use this tag to insert content into component's slots.
{% fill %}
tag may be used only within a{% component %}..{% endcomponent %}
block. Runtime checks should prohibit other usages.Args:
name
(str, required): Name of the slot to insert this content into. Use\"default\"
for the default slot.default
(str, optional): This argument allows you to access the original content of the slot under the specified variable name. See Accessing original content of slotsdata
(str, optional): This argument allows you to access the data passed to the slot under the specified variable name. See Scoped slots
Examples:
Basic usage:
"},{"location":"reference/template_tags/#accessing-slots-default-content-with-the-default-kwarg","title":"Accessing slot's default content with the{% component \"my_table\" %}\n {% fill \"pagination\" %}\n < 1 | 2 | 3 >\n {% endfill %}\n{% endcomponent %}\n
default
kwarg","text":"{# my_table.html #}\n<table>\n ...\n {% slot \"pagination\" %}\n < 1 | 2 | 3 >\n {% endslot %}\n</table>\n
"},{"location":"reference/template_tags/#accessing-slots-data-with-the-data-kwarg","title":"Accessing slot's data with the{% component \"my_table\" %}\n {% fill \"pagination\" default=\"default_pag\" %}\n <div class=\"my-class\">\n {{ default_pag }}\n </div>\n {% endfill %}\n{% endcomponent %}\n
data
kwarg","text":"{# my_table.html #}\n<table>\n ...\n {% slot \"pagination\" pages=pages %}\n < 1 | 2 | 3 >\n {% endslot %}\n</table>\n
"},{"location":"reference/template_tags/#accessing-slot-data-and-default-content-on-the-default-slot","title":"Accessing slot data and default content on the default slot","text":"{% component \"my_table\" %}\n {% fill \"pagination\" data=\"slot_data\" %}\n {% for page in slot_data.pages %}\n <a href=\"{{ page.link }}\">\n {{ page.index }}\n </a>\n {% endfor %}\n {% endfill %}\n{% endcomponent %}\n
To access slot data and the default slot content on the default slot, use
{% fill %}
withname
set to\"default\"
:
"},{"location":"reference/template_tags/#html_attrs","title":"html_attrs","text":"{% component \"button\" %}\n {% fill name=\"default\" data=\"slot_data\" default=\"default_slot\" %}\n You clicked me {{ slot_data.count }} times!\n {{ default_slot }}\n {% endfill %}\n{% endcomponent %}\n
{% html_attrs attrs: Optional[Dict] = None, defaults: Optional[Dict] = None, **kwargs: Any %}\n
See source code
Generate HTML attributes (
key=\"value\"
), combining data from multiple sources, whether its template variables or static text.It is designed to easily merge HTML attributes passed from outside with the internal. See how to in Passing HTML attributes to components.
Args:
attrs
(dict, optional): Optional dictionary that holds HTML attributes. On conflict, overrides values in thedefault
dictionary.default
(str, optional): Optional dictionary that holds HTML attributes. On conflict, is overriden with values in theattrs
dictionary.- Any extra kwargs will be appended to the corresponding keys
The attributes in
attrs
anddefaults
are merged and resulting dict is rendered as HTML attributes (key=\"value\"
).Extra kwargs (
key=value
) are concatenated to existing keys. So if we haveattrs = {\"class\": \"my-class\"}\n
Then
{% html_attrs attrs class=\"extra-class\" %}\n
will result in
class=\"my-class extra-class\"
.Example:
<div {% html_attrs\n attrs\n defaults:class=\"default-class\"\n class=\"extra-class\"\n data-id=\"123\"\n%}>\n
renders
<div class=\"my-class extra-class\" data-id=\"123\">\n
See more usage examples in HTML attributes.
"},{"location":"reference/template_tags/#provide","title":"provide","text":"{% provide name: str, **kwargs: Any %}\n{% endprovide %}\n
See source code
The \"provider\" part of the provide / inject feature. Pass kwargs to this tag to define the provider's data. Any components defined within the
{% provide %}..{% endprovide %}
tags will be able to access this data withComponent.inject()
.This is similar to React's
ContextProvider
, or Vue'sprovide()
.Args:
name
(str, required): Provider name. This is the name you will then use inComponent.inject()
.**kwargs
: Any extra kwargs will be passed as the provided data.
Example:
Provide the \"user_data\" in parent component:
@register(\"parent\")\nclass Parent(Component):\n template = \"\"\"\n <div>\n {% provide \"user_data\" user=user %}\n {% component \"child\" / %}\n {% endprovide %}\n </div>\n \"\"\"\n\n def get_context_data(self, user: User):\n return {\n \"user\": user,\n }\n
Since the \"child\" component is used within the
{% provide %} / {% endprovide %}
tags, we can request the \"user_data\" usingComponent.inject(\"user_data\")
:@register(\"child\")\nclass Child(Component):\n template = \"\"\"\n <div>\n User is: {{ user }}\n </div>\n \"\"\"\n\n def get_context_data(self):\n user = self.inject(\"user_data\").user\n return {\n \"user\": user,\n }\n
Notice that the keys defined on the
{% provide %}
tag are then accessed as attributes when accessing them withComponent.inject()
.\u2705 Do this
user = self.inject(\"user_data\").user\n
\u274c Don't do this
"},{"location":"reference/template_tags/#slot","title":"slot","text":"user = self.inject(\"user_data\")[\"user\"]\n
{% slot name: str, **kwargs: Any [default] [required] %}\n{% endslot %}\n
See source code
Slot tag marks a place inside a component where content can be inserted from outside.
Learn more about using slots.
This is similar to slots as seen in Web components, Vue or React's
children
.Args:
name
(str, required): Registered name of the component to renderdefault
: Optional flag. If there is a default slot, you can pass the component slot content without using the{% fill %}
tag. See Default slotrequired
: Optional flag. Will raise an error if a slot is required but not given.**kwargs
: Any extra kwargs will be passed as the slot data.
Example:
@register(\"child\")\nclass Child(Component):\n template = \"\"\"\n <div>\n {% slot \"content\" default %}\n This is shown if not overriden!\n {% endslot %}\n </div>\n <aside>\n {% slot \"sidebar\" required / %}\n </aside>\n \"\"\"\n
"},{"location":"reference/template_tags/#passing-data-to-slots","title":"Passing data to slots","text":"@register(\"parent\")\nclass Parent(Component):\n template = \"\"\"\n <div>\n {% component \"child\" %}\n {% fill \"content\" %}\n \ud83d\uddde\ufe0f\ud83d\udcf0\n {% endfill %}\n\n {% fill \"sidebar\" %}\n \ud83c\udf77\ud83e\uddc9\ud83c\udf7e\n {% endfill %}\n {% endcomponent %}\n </div>\n \"\"\"\n
Any extra kwargs will be considered as slot data, and will be accessible in the
{% fill %}
tag via fill'sdata
kwarg:@register(\"child\")\nclass Child(Component):\n template = \"\"\"\n <div>\n {# Passing data to the slot #}\n {% slot \"content\" user=user %}\n This is shown if not overriden!\n {% endslot %}\n </div>\n \"\"\"\n
"},{"location":"reference/template_tags/#accessing-default-slot-content","title":"Accessing default slot content","text":"@register(\"parent\")\nclass Parent(Component):\n template = \"\"\"\n {# Parent can access the slot data #}\n {% component \"child\" %}\n {% fill \"content\" data=\"data\" %}\n <div class=\"wrapper-class\">\n {{ data.user }}\n </div>\n {% endfill %}\n {% endcomponent %}\n \"\"\"\n
The content between the
{% slot %}..{% endslot %}
tags is the default content that will be rendered if no fill is given for the slot.This default content can then be accessed from within the
{% fill %}
tag using the fill'sdefault
kwarg. This is useful if you need to wrap / prepend / append the original slot's content.@register(\"child\")\nclass Child(Component):\n template = \"\"\"\n <div>\n {% slot \"content\" %}\n This is default content!\n {% endslot %}\n </div>\n \"\"\"\n
"},{"location":"reference/template_vars/","title":"Template vars","text":""},{"location":"reference/template_vars/#template-variables","title":"Template variables","text":"@register(\"parent\")\nclass Parent(Component):\n template = \"\"\"\n {# Parent can access the slot's default content #}\n {% component \"child\" %}\n {% fill \"content\" default=\"default\" %}\n {{ default }}\n {% endfill %}\n {% endcomponent %}\n \"\"\"\n
Here is a list of all variables that are automatically available from inside the component's template and in
"},{"location":"reference/template_vars/#django_components.component.ComponentVars.is_filled","title":"is_filledon_render_before
/on_render_after
hooks.instance-attribute
","text":"is_filled: Dict[str, bool]\n
See source code
Dictonary describing which component slots are filled (
True
) or are not (False
).New in version 0.70
Use as
{{ component_vars.is_filled }}
Example:
{# Render wrapping HTML only if the slot is defined #}\n{% if component_vars.is_filled.my_slot %}\n <div class=\"slot-wrapper\">\n {% slot \"my_slot\" / %}\n </div>\n{% endif %}\n
This is equivalent to checking if a given key is among the slot fills:
"},{"location":"reference/urls/","title":"Urls","text":""},{"location":"reference/urls/#urls","title":"URLs","text":"class MyTable(Component):\n def get_context_data(self, *args, **kwargs):\n return {\n \"my_slot_filled\": \"my_slot\" in self.input.slots\n }\n
Below are all the URL patterns that will be added by adding
django_components.urls
.See Installation on how to add these URLs to your Django project.
Django components already prefixes all URLs with
components/
. So when you are adding the URLs tourlpatterns
, you can use an empty string as the first argument:
"},{"location":"reference/urls/#list-of-urls","title":"List of URLs","text":"from django.urls import include, path\n\nurlpatterns = [\n ...\n path(\"\", include(\"django_components.urls\")),\n]\n
-
components/cache/<str:comp_cls_hash>.<str:input_hash>.<str:script_type>
-
components/cache/<str:comp_cls_hash>.<str:script_type>
- Fix thread unsafe media resolve validation by moving it to ComponentMedia