Commit a391b17a authored by Matthew Somerville's avatar Matthew Somerville Committed by Tim Graham
Browse files

Fixed #23516 -- Added caching of include tag Template objects 

This also speeds up for loops that render the same template
multiple times.
parent 2a7c59cd

django/template/loader_tags.py

+14 −2
Original line number Diff line number Diff line
@@ -171,6 +171,8 @@ class ExtendsNode(Node): 




class IncludeNode(Node):

    context_key = '__include_context'



    def __init__(self, template, *args, **kwargs):

        self.template = template

        self.extra_context = kwargs.pop('extra_context', {})
@@ -178,12 +180,22 @@ class IncludeNode(Node): 
        super(IncludeNode, self).__init__(*args, **kwargs)



    def render(self, context):

        """

        Render the specified template and context. Cache the template object

        in render_context to avoid reparsing and loading when used in a for

        loop.

        """

        try:

            template = self.template.resolve(context)

            # Does this quack like a Template?

            if not callable(getattr(template, 'render', None)):

                # If not, we'll try get_template

                template = context.template.engine.get_template(template)

                # If not, we'll try our cache, and get_template()

                template_name = template

                cache = context.render_context.setdefault(self.context_key, {})

                template = cache.get(template_name)

                if template is None:

                    template = context.template.engine.get_template(template_name)

                    cache[template_name] = template

            values = {

                name: var.resolve(context)

                for name, var in six.iteritems(self.extra_context)

docs/releases/1.9.txt

+3 −0
Original line number Diff line number Diff line
@@ -314,6 +314,9 @@ Templates 
* The ``timesince`` and ``timeuntil`` filters were improved to deal with leap

  years when given large time spans.



* The ``include`` tag now caches parsed templates objects during template

  rendering, speeding up reuse in places such as for loops.



Requests and Responses

^^^^^^^^^^^^^^^^^^^^^^

tests/template_tests/syntax_tests/test_if_changed.py

+14 −0
Original line number Diff line number Diff line
@@ -196,3 +196,17 @@ class IfChangedTests(SimpleTestCase): 
        template = self.engine.from_string('{% ifchanged %}{% cycle "1st time" "2nd time" %}{% endifchanged %}')

        output = template.render(Context({}))

        self.assertEqual(output, '1st time')



    def test_include(self):

        """

        #23516 -- This works as a regression test only if the cached loader

        isn't used. Hence we don't use the @setup decorator.

        """

        engine = Engine(loaders=[

            ('django.template.loaders.locmem.Loader', {

                'template': '{% for x in vars %}{% include "include" %}{% endfor %}',

                'include': '{% ifchanged %}{{ x }}{% endifchanged %}',

            }),

        ])

        output = engine.render_to_string('template', dict(vars=[1, 1, 2, 2, 3, 3]))

        self.assertEqual(output, "123")