Fixed #14908 -- Added a 'takes_context' argument to simple_tag. Thanks to... (314fabc9) · Commits · Dom Sekotill / django

django/template/base.py

+31 −12

Original line number	Diff line number	Diff line
		@@ -872,8 +872,14 @@ class Library(object):
		self.filters[getattr(func, "_decorated_function", func).__name__] = func
		return func

		def simple_tag(self,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):
		@@ -881,13 +887,26 @@ class Library(object):

		def render(self, context):
		resolved_vars = [var.resolve(context) for var in self.vars_to_resolve]
		return func(*resolved_vars)
		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

		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):
		params, xx, xxx, defaults = getargspec(func)

docs/howto/custom-template-tags.txt

+21 −3

Original line number	Diff line number	Diff line
		@@ -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:

docs/releases/1.3.txt

+6 −2

Original line number	Diff line number	Diff line
		@@ -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:

tests/regressiontests/templates/custom.py

+45 −2

Original line number	Diff line number	Diff line
		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)

tests/regressiontests/templates/templatetags/custom.py

+30 −0

Original line number	Diff line number	Diff line
		@@ -9,3 +9,33 @@ trim = stringfilter(trim)

		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__"