[patch] includeblock tag

[Chris Beaven]

Similar to {% include %} but rather than rendering the entire template, this renders a specific block of the given template with the current context.

Both the template name and the block name can either be variables or hard-coded (quoted) strings.

The following example includes the "navigation" block of the template "main.htm":

{% includeblock "main.htm" "navigation" %}

[Chris Beaven]

patch including tests and documentation

[Adrian Holovaty]

Not "core" enough for Django proper, and it's yet another way of including things -- we've already got ssi, include and blocks -- but please do post this to the user-contributed template tags/filters part of the Django wiki.

[Antonis Christofides]

Note that the patch included appears to be too slow. This is probably because it needs to load/compile the entire included template each time a block is needed, so if, for example, you have

{% includeblock "main.htm" "block1" %}
{% includeblock "main.htm" "block2" %}
{% includeblock "main.htm" "block3" %}

then it appears to be loading and compiling main.htm three times. You can be orders of magnitude faster if, instead, you break main.htm into smaller files and simply {% include %} the smaller files whenever you need them.

[Chris Beaven]

I'm apathetic about the patch now, anyway. But the load-compile slowness is a generic problem which I addressed in a more recent ticket by caching templates.

[Johannes Dollinger]

I have a ​patch(1) that introduces a template cache in Context and would make something like the following trivial to implement:

{% sub "block1" %}
...
{% endsub %}

{% include "block1" %}

Would that fit the orginal use-case?

(1) ​http://einfallsreich.net/projekte/thenewstuff/django/