mirror of
https://github.com/django/django.git
synced 2025-08-03 18:38:50 +00:00
Fixed #3453: introduced a new template variable resolution system by Brian Harring (thanks!). The upshot is that variable resolution is about 25% faster, and you should see a measurable performance increase any time you've got long or deeply nested loops.
Variable resolution has changed behind the scenes -- see the note in templates_python.txt -- but template.resolve_variable() still exists. This should be fully backwards-compatible. git-svn-id: http://code.djangoproject.com/svn/django/trunk@6399 bcc190cf-cafb-0310-a4f2-bffc1f526a37
This commit is contained in:
parent
75e462099b
commit
2570954a9a
8 changed files with 168 additions and 74 deletions
|
@ -928,10 +928,36 @@ current context, available in the ``render`` method::
|
|||
``resolve_variable`` will try to resolve ``blog_entry.date_updated`` and then
|
||||
format it accordingly.
|
||||
|
||||
.. note::
|
||||
The ``resolve_variable()`` function will throw a ``VariableDoesNotExist``
|
||||
exception if it cannot resolve the string passed to it in the current
|
||||
context of the page.
|
||||
.. admonition:: New in development version:
|
||||
|
||||
Variable resolution has changed in the development version of Django.
|
||||
``template.resolve_variable()`` is still available, but has been deprecated
|
||||
in favor of a new ``template.Variable`` class. Using this class will usually
|
||||
be more efficient than calling ``template.resolve_variable``
|
||||
|
||||
To use the ``Variable`` class, simply instantiate it with the name of the
|
||||
variable to be resolved, and then call ``variable.resolve(context)``. So,
|
||||
in the development version, the above example would be more correctly
|
||||
written as:
|
||||
|
||||
.. parsed-literal::
|
||||
|
||||
class FormatTimeNode(template.Node):
|
||||
def __init__(self, date_to_be_formatted, format_string):
|
||||
self.date_to_be_formatted = **Variable(date_to_be_formatted)**
|
||||
self.format_string = format_string
|
||||
|
||||
def render(self, context):
|
||||
try:
|
||||
actual_date = **self.date_to_be_formatted.resolve(context)**
|
||||
return actual_date.strftime(self.format_string)
|
||||
except template.VariableDoesNotExist:
|
||||
return ''
|
||||
|
||||
Changes are highlighted in bold.
|
||||
|
||||
Variable resolution will throw a ``VariableDoesNotExist`` exception if it cannot
|
||||
resolve the string passed to it in the current context of the page.
|
||||
|
||||
Shortcut for simple tags
|
||||
~~~~~~~~~~~~~~~~~~~~~~~~
|
||||
|
|
Loading…
Add table
Add a link
Reference in a new issue