simple include tag doesn't layer context like normal include tag

[Kenneth Arnold]

This was surprising behavior: unlike the provided include tag, user-defined include tags don't layer the provided context on top of the existing context.

It is consistent with a strict reading of the docs, but it's a confusing and un-motivated difference from ordinary include behavior.

I'm attaching a quick and dirty patch to fix this. The needed design decision is exactly how the context class should be handled; is there a use case for something other than just Context? (RequestContext needs another parameter...)

[Matt McClanahan]

Inclusion tags can receive the template context. See 'takes_context'. ​http://www.djangoproject.com/documentation/templates_python/#inclusion-tags

[Kenneth Arnold]

Point. (Yes I knew about that, but I didn't see the use case.)

Suggest adding to the docs something like: "You can replace

{% with id=thing.id %}{% include "other.html" %}{% endwith %}

with a custom tag:

@register.simple_tag('other.html', takes_context=True)
def other(context, id):
  context[id] = id
  return context

and simpler code:

{% other thing.id %}

Alternatively, make the previous proposed behavior the default if context_class is not provided, with the meaning "If I provide my own context class, I want to control how context handling happens. Otherwise, do it the way I'm used to include tags doing it.".

[Julien Phalip]

This has been fixed in #14987.