Fixed #14262 -- Added new assignment_tag as a simple way to assign the result of a template tag to a context variable. Thanks, Julien Phalip.

git-svn-id: http://code.djangoproject.com/svn/django/trunk@16149 bcc190cf-cafb-0310-a4f2-bffc1f526a37

tests/regressiontests/templates/custom.py

@@ -1,3 +1,5 @@
+from __future__ import with_statement
+
 from django import template
 from django.utils.unittest import TestCase
 from templatetags import custom
@@ -102,3 +104,54 @@ class CustomTagTests(TestCase):
 
         c.use_l10n = True
         self.assertEquals(t.render(c).strip(), u'True')
+
+    def test_assignment_tags(self):
+        c = template.Context({'value': 42})
+
+        t = template.Template('{% load custom %}{% assignment_no_params as var %}The result is: {{ var }}')
+        self.assertEqual(t.render(c), u'The result is: assignment_no_params - Expected result')
+
+        t = template.Template('{% load custom %}{% assignment_one_param 37 as var %}The result is: {{ var }}')
+        self.assertEqual(t.render(c), u'The result is: assignment_one_param - Expected result: 37')
+
+        t = template.Template('{% load custom %}{% assignment_explicit_no_context 37 as var %}The result is: {{ var }}')
+        self.assertEqual(t.render(c), u'The result is: assignment_explicit_no_context - Expected result: 37')
+
+        t = template.Template('{% load custom %}{% assignment_no_params_with_context as var %}The result is: {{ var }}')
+        self.assertEqual(t.render(c), u'The result is: assignment_no_params_with_context - Expected result (context value: 42)')
+
+        t = template.Template('{% load custom %}{% assignment_params_and_context 37 as var %}The result is: {{ var }}')
+        self.assertEqual(t.render(c), u'The result is: assignment_params_and_context - Expected result (context value: 42): 37')
+
+        self.assertRaisesRegexp(template.TemplateSyntaxError,
+            "'assignment_one_param' tag takes at least 2 arguments and the second last argument must be 'as'",
+            template.Template, '{% load custom %}{% assignment_one_param 37 %}The result is: {{ var }}')
+
+        self.assertRaisesRegexp(template.TemplateSyntaxError,
+            "'assignment_one_param' tag takes at least 2 arguments and the second last argument must be 'as'",
+            template.Template, '{% load custom %}{% assignment_one_param 37 as %}The result is: {{ var }}')
+
+        self.assertRaisesRegexp(template.TemplateSyntaxError,
+            "'assignment_one_param' tag takes at least 2 arguments and the second last argument must be 'as'",
+            template.Template, '{% load custom %}{% assignment_one_param 37 ass var %}The result is: {{ var }}')
+
+    def test_assignment_tag_registration(self):
+        # Test that the decorators preserve the decorated function's docstring, name and attributes.
+        self.verify_tag(custom.assignment_no_params, 'assignment_no_params')
+        self.verify_tag(custom.assignment_one_param, 'assignment_one_param')
+        self.verify_tag(custom.assignment_explicit_no_context, 'assignment_explicit_no_context')
+        self.verify_tag(custom.assignment_no_params_with_context, 'assignment_no_params_with_context')
+        self.verify_tag(custom.assignment_params_and_context, 'assignment_params_and_context')
+
+    def test_assignment_tag_missing_context(self):
+        # That the 'context' parameter must be present when takes_context is True
+        def an_assignment_tag_without_parameters(arg):
+            """Expected __doc__"""
+            return "Expected result"
+
+        register = template.Library()
+        decorator = register.assignment_tag(takes_context=True)
+
+        self.assertRaisesRegexp(template.TemplateSyntaxError,
+            "Any tag function decorated with takes_context=True must have a first argument of 'context'",
+            decorator, an_assignment_tag_without_parameters)

tests/regressiontests/templates/templatetags/custom.py

@@ -84,3 +84,33 @@ def use_l10n(context):
 @register.inclusion_tag('test_incl_tag_use_l10n.html', takes_context=True)
 def inclusion_tag_use_l10n(context):
     return {}
+
+@register.assignment_tag
+def assignment_no_params():
+    """Expected assignment_no_params __doc__"""
+    return "assignment_no_params - Expected result"
+assignment_no_params.anything = "Expected assignment_no_params __dict__"
+
+@register.assignment_tag
+def assignment_one_param(arg):
+    """Expected assignment_one_param __doc__"""
+    return "assignment_one_param - Expected result: %s" % arg
+assignment_one_param.anything = "Expected assignment_one_param __dict__"
+
+@register.assignment_tag(takes_context=False)
+def assignment_explicit_no_context(arg):
+    """Expected assignment_explicit_no_context __doc__"""
+    return "assignment_explicit_no_context - Expected result: %s" % arg
+assignment_explicit_no_context.anything = "Expected assignment_explicit_no_context __dict__"
+
+@register.assignment_tag(takes_context=True)
+def assignment_no_params_with_context(context):
+    """Expected assignment_no_params_with_context __doc__"""
+    return "assignment_no_params_with_context - Expected result (context value: %s)" % context['value']
+assignment_no_params_with_context.anything = "Expected assignment_no_params_with_context __dict__"
+
+@register.assignment_tag(takes_context=True)
+def assignment_params_and_context(context, arg):
+    """Expected assignment_params_and_context __doc__"""
+    return "assignment_params_and_context - Expected result (context value: %s): %s" % (context['value'], arg)
+assignment_params_and_context.anything = "Expected assignment_params_and_context __dict__"