fix: populate RequestContext with context processors (#643)

src/django_components/component.py

@@ -1,6 +1,7 @@
 import inspect
 import types
 from collections import deque
+from contextlib import contextmanager
 from dataclasses import dataclass
 from typing import (
     Any,
@@ -8,6 +9,7 @@ from typing import (
     ClassVar,
     Deque,
     Dict,
+    Generator,
     Generic,
     List,
     Literal,
@@ -520,22 +522,7 @@ class Component(Generic[ArgsType, KwargsType, DataType, SlotsType], metaclass=Co
         context_data = self.get_context_data(*args, **kwargs)
         self._validate_outputs(context_data)
 
-        with context.update(context_data):
-            template = self.get_template(context)
-            _monkeypatch_template(template)
-
-            if context.template is None:
-                # Associate the newly-created Context with a Template, otherwise we get
-                # an error when we try to use `{% include %}` tag inside the template?
-                # See https://github.com/EmilStenstrom/django-components/issues/580
-                context.template = template
-                context.template_name = template.name
-
-            # Set `Template._dc_is_component_nested` based on whether we're currently INSIDE
-            # the `{% extends %}` tag.
-            # Part of fix for https://github.com/EmilStenstrom/django-components/issues/508
-            template._dc_is_component_nested = bool(context.render_context.get(BLOCK_CONTEXT_KEY))
-
+        with _prepare_template(self, context, context_data) as template:
             # Support passing slots explicitly to `render` method
             if has_slots:
                 fill_content = self._fills_from_slots_data(
@@ -843,3 +830,35 @@ def _monkeypatch_template(template: Template) -> None:
 
     # See https://stackoverflow.com/a/42154067/9788634
     template.render = types.MethodType(_template_render, template)
+
+
+@contextmanager
+def _maybe_bind_template(context: Context, template: Template) -> Generator[None, Any, None]:
+    if context.template is None:
+        with context.bind_template(template):
+            yield
+    else:
+        yield
+
+
+@contextmanager
+def _prepare_template(
+    component: Component,
+    context: Context,
+    context_data: Any,
+) -> Generator[Template, Any, None]:
+    with context.update(context_data):
+        # Associate the newly-created Context with a Template, otherwise we get
+        # an error when we try to use `{% include %}` tag inside the template?
+        # See https://github.com/EmilStenstrom/django-components/issues/580
+        # And https://github.com/EmilStenstrom/django-components/issues/634
+        template = component.get_template(context)
+        _monkeypatch_template(template)
+
+        # Set `Template._dc_is_component_nested` based on whether we're currently INSIDE
+        # the `{% extends %}` tag.
+        # Part of fix for https://github.com/EmilStenstrom/django-components/issues/508
+        template._dc_is_component_nested = bool(context.render_context.get(BLOCK_CONTEXT_KEY))
+
+        with _maybe_bind_template(context, template):
+            yield template

tests/test_component.py

@@ -3,6 +3,7 @@ Tests focusing on the Component class.
 For tests focusing on the `component` tag, see `test_templatetags_component.py`
 """
 
+import re
 import sys
 from typing import Any, Dict, Tuple, Union, no_type_check
 
@@ -14,13 +15,16 @@ else:
 
 from unittest import skipIf
 
+from django.conf import settings
 from django.core.exceptions import ImproperlyConfigured
 from django.http import HttpRequest, HttpResponse
 from django.template import Context, RequestContext, Template, TemplateSyntaxError
 from django.template.base import TextNode
+from django.test import Client
+from django.urls import path
 from django.utils.safestring import SafeString
 
-from django_components import Component, SlotFunc, registry, types
+from django_components import Component, ComponentView, SlotFunc, register, registry, types
 from django_components.slots import SlotRef
 
 from .django_test_setup import setup_test_config
@@ -29,6 +33,21 @@ from .testutils import BaseTestCase, parametrize_context_behavior
 setup_test_config({"autodiscover": False})
 
 
+# Client for testing endpoints via requests
+class CustomClient(Client):
+    def __init__(self, urlpatterns=None, *args, **kwargs):
+        import types
+
+        if urlpatterns:
+            urls_module = types.ModuleType("urls")
+            urls_module.urlpatterns = urlpatterns  # type: ignore
+            settings.ROOT_URLCONF = urls_module
+        else:
+            settings.ROOT_URLCONF = __name__
+        settings.SECRET_KEY = "secret"  # noqa
+        super().__init__(*args, **kwargs)
+
+
 # Component typings
 CompArgs = Tuple[int, str]
 
@@ -772,6 +791,7 @@ class ComponentRenderTest(BaseTestCase):
         )
 
     # See https://github.com/EmilStenstrom/django-components/issues/580
+    # And https://github.com/EmilStenstrom/django-components/issues/634
     # And https://github.com/EmilStenstrom/django-components/commit/fee26ec1d8b46b5ee065ca1ce6143889b0f96764
     @parametrize_context_behavior(["django", "isolated"])
     def test_render_with_include_and_request_context(self):
@@ -793,6 +813,63 @@ class ComponentRenderTest(BaseTestCase):
             """,
         )
 
+    # See https://github.com/EmilStenstrom/django-components/issues/580
+    # And https://github.com/EmilStenstrom/django-components/issues/634
+    @parametrize_context_behavior(["django", "isolated"])
+    def test_request_context_is_populated_from_context_processors(self):
+        @register("thing")
+        class Thing(Component):
+            template: types.django_html = """
+                <kbd>Rendered {{ how }}</kbd>
+                <div>
+                    CSRF token: {{ csrf_token|default:"<em>No CSRF token</em>" }}
+                </div>
+            """
+
+            def get_context_data(self, *args, how: str, **kwargs):
+                return {"how": how}
+
+            class View(ComponentView):
+                def get(self, request):
+                    how = "via GET request"
+
+                    return self.component.render_to_response(
+                        context=RequestContext(self.request),
+                        kwargs=self.component.get_context_data(how=how),
+                    )
+
+        client = CustomClient(urlpatterns=[path("test_thing/", Thing.as_view())])
+        response = client.get("/test_thing/")
+
+        self.assertEqual(response.status_code, 200)
+
+        # Full response:
+        # """
+        # <kbd>
+        #     Rendered via GET request
+        # </kbd>
+        # <div>
+        #     CSRF token:
+        #     <div>
+        #         test_csrf_token
+        #     </div>
+        # </div>
+        # """
+        self.assertInHTML(
+            """
+            <kbd>
+                Rendered via GET request
+            </kbd>
+            """,
+            response.content.decode(),
+        )
+
+        token_re = re.compile(rb"CSRF token:\s+(?P<token>[0-9a-zA-Z]{64})")
+        token = token_re.findall(response.content)[0]
+
+        self.assertTrue(token)
+        self.assertEqual(len(token), 64)
+
     @parametrize_context_behavior(["django", "isolated"])
     def test_render_with_extends(self):
         class SimpleComponent(Component):