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Fixed #14908 -- Added a 'takes_context' argument to simple_tag. Thank…

…s to Julien Phalip for driving the issue and providing the final patch.

git-svn-id: http://code.djangoproject.com/svn/django/trunk@14987 bcc190cf-cafb-0310-a4f2-bffc1f526a37
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1 parent 7adffae commit 314fabc930a1bb361ca06e9c948bb726ad8df99a @freakboy3742 freakboy3742 committed Dec 19, 2010
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43 django/template/base.py
@@ -872,21 +872,40 @@ def filter_function(self, func):
self.filters[getattr(func, "_decorated_function", func).__name__] = func
return func
- def simple_tag(self,func):
- params, xx, xxx, defaults = getargspec(func)
+ def simple_tag(self, func=None, takes_context=None):
+ def dec(func):
+ params, xx, xxx, defaults = getargspec(func)
+ if takes_context:
+ if params[0] == 'context':
+ params = params[1:]
+ else:
+ raise TemplateSyntaxError("Any tag function decorated with takes_context=True must have a first argument of 'context'")
- class SimpleNode(Node):
- def __init__(self, vars_to_resolve):
- self.vars_to_resolve = map(Variable, vars_to_resolve)
+ class SimpleNode(Node):
+ def __init__(self, vars_to_resolve):
+ self.vars_to_resolve = map(Variable, vars_to_resolve)
- def render(self, context):
- resolved_vars = [var.resolve(context) for var in self.vars_to_resolve]
- return func(*resolved_vars)
+ def render(self, context):
+ resolved_vars = [var.resolve(context) for var in self.vars_to_resolve]
+ if takes_context:
+ func_args = [context] + resolved_vars
+ else:
+ func_args = resolved_vars
+ return func(*func_args)
- compile_func = curry(generic_tag_compiler, params, defaults, getattr(func, "_decorated_function", func).__name__, SimpleNode)
- compile_func.__doc__ = func.__doc__
- self.tag(getattr(func, "_decorated_function", func).__name__, compile_func)
- return func
+ compile_func = curry(generic_tag_compiler, params, defaults, getattr(func, "_decorated_function", func).__name__, SimpleNode)
+ compile_func.__doc__ = func.__doc__
+ self.tag(getattr(func, "_decorated_function", func).__name__, compile_func)
+ return func
+
+ if func is None:
+ # @register.simple_tag(...)
+ return dec
+ elif callable(func):
+ # @register.simple_tag
+ return dec(func)
+ else:
+ raise TemplateSyntaxError("Invalid arguments provided to simple_tag")
def inclusion_tag(self, file_name, context_class=Context, takes_context=False):
def dec(func):
View
24 docs/howto/custom-template-tags.txt
@@ -669,9 +669,27 @@ A couple of things to note about the ``simple_tag`` helper function:
* If the argument was a template variable, our function is passed the
current value of the variable, not the variable itself.
-When your template tag does not need access to the current context, writing a
-function to work with the input values and using the ``simple_tag`` helper is
-the easiest way to create a new tag.
+.. versionadded:: 1.3
+
+If your template tag needs to access the current context, you can use the
+``takes_context`` argument when registering your tag::
+
+ # The first argument *must* be called "context" here.
+ def current_time(context, format_string):
+ timezone = context['timezone']
+ return your_get_current_time_method(timezone)
+
+ register.simple_tag(takes_context=True)(current_time)
+
+Or, using decorator syntax::
+
+ @register.simple_tag(takes_context=True)
+ def current_time(context, format_string):
+ timezone = context['timezone']
+ return your_get_current_time_method(timezone)
+
+For more information on how the ``takes_context`` option works, see the section
+on `inclusion tags`_.
.. _howto-custom-template-tags-inclusion-tags:
View
8 docs/releases/1.3.txt
@@ -184,12 +184,16 @@ requests. These include:
* Support for _HTTPOnly cookies.
- * mail_admins() and mail_managers() now support easily attaching
- HTML content to messages.
+ * :meth:`mail_admins()` and :meth:`mail_managers()` now support
+ easily attaching HTML content to messages.
* Error emails now include more of the detail and formatting of
the debug server error page.
+ * :meth:`simple_tag` now accepts a :attr:`takes_context` argument,
+ making it easier to write simple template tags that require
+ access to template context.
+
.. _HTTPOnly: http://www.owasp.org/index.php/HTTPOnly
.. _backwards-incompatible-changes-1.3:
View
47 tests/regressiontests/templates/custom.py
@@ -1,11 +1,54 @@
from django import template
from django.utils.unittest import TestCase
+from templatetags import custom
-
-class CustomTests(TestCase):
+class CustomFilterTests(TestCase):
def test_filter(self):
t = template.Template("{% load custom %}{{ string|trim:5 }}")
self.assertEqual(
t.render(template.Context({"string": "abcdefghijklmnopqrstuvwxyz"})),
u"abcde"
)
+
+
+class CustomTagTests(TestCase):
+ def verify_tag(self, tag, name):
+ self.assertEquals(tag.__name__, name)
+ self.assertEquals(tag.__doc__, 'Expected %s __doc__' % name)
+ self.assertEquals(tag.__dict__['anything'], 'Expected %s __dict__' % name)
+
+ def test_simple_tags(self):
+ c = template.Context({'value': 42})
+
+ t = template.Template('{% load custom %}{% no_params %}')
+ self.assertEquals(t.render(c), u'no_params - Expected result')
+
+ t = template.Template('{% load custom %}{% one_param 37 %}')
+ self.assertEquals(t.render(c), u'one_param - Expected result: 37')
+
+ t = template.Template('{% load custom %}{% explicit_no_context 37 %}')
+ self.assertEquals(t.render(c), u'explicit_no_context - Expected result: 37')
+
+ t = template.Template('{% load custom %}{% no_params_with_context %}')
+ self.assertEquals(t.render(c), u'no_params_with_context - Expected result (context value: 42)')
+
+ t = template.Template('{% load custom %}{% params_and_context 37 %}')
+ self.assertEquals(t.render(c), u'params_and_context - Expected result (context value: 42): 37')
+
+ def test_simple_tag_registration(self):
+ # Test that the decorators preserve the decorated function's docstring, name and attributes.
+ self.verify_tag(custom.no_params, 'no_params')
+ self.verify_tag(custom.one_param, 'one_param')
+ self.verify_tag(custom.explicit_no_context, 'explicit_no_context')
+ self.verify_tag(custom.no_params_with_context, 'no_params_with_context')
+ self.verify_tag(custom.params_and_context, 'params_and_context')
+
+ def test_simple_tag_missing_context(self):
+ # That the 'context' parameter must be present when takes_context is True
+ def a_simple_tag_without_parameters(arg):
+ """Expected __doc__"""
+ return "Expected result"
+
+ register = template.Library()
+ decorator = register.simple_tag(takes_context=True)
+ self.assertRaises(template.TemplateSyntaxError, decorator, a_simple_tag_without_parameters)
View
30 tests/regressiontests/templates/templatetags/custom.py
@@ -9,3 +9,33 @@ def trim(value, num):
register.filter(trim)
+@register.simple_tag
+def no_params():
+ """Expected no_params __doc__"""
+ return "no_params - Expected result"
+no_params.anything = "Expected no_params __dict__"
+
+@register.simple_tag
+def one_param(arg):
+ """Expected one_param __doc__"""
+ return "one_param - Expected result: %s" % arg
+one_param.anything = "Expected one_param __dict__"
+
+@register.simple_tag(takes_context=False)
+def explicit_no_context(arg):
+ """Expected explicit_no_context __doc__"""
+ return "explicit_no_context - Expected result: %s" % arg
+explicit_no_context.anything = "Expected explicit_no_context __dict__"
+
+@register.simple_tag(takes_context=True)
+def no_params_with_context(context):
+ """Expected no_params_with_context __doc__"""
+ return "no_params_with_context - Expected result (context value: %s)" % context['value']
+no_params_with_context.anything = "Expected no_params_with_context __dict__"
+
+@register.simple_tag(takes_context=True)
+def params_and_context(context, arg):
+ """Expected params_and_context __doc__"""
+ return "params_and_context - Expected result (context value: %s): %s" % (context['value'], arg)
+params_and_context.anything = "Expected params_and_context __dict__"
+
View
2 tests/regressiontests/templates/tests.py
@@ -23,7 +23,7 @@
from django.utils.tzinfo import LocalTimezone
from context import ContextTests
-from custom import CustomTests
+from custom import CustomTagTests, CustomFilterTests
from parser import ParserTests
from unicode import UnicodeTests
from nodelist import NodelistTest

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