IsInstance in Django template?

Question

Is there a way to do isinstance/issubclass in a Django template? I realise I can write my own templatetag, but I'm surprised this isn't possibly which makes me think I'm either doing something wrong or missing something obvious.

I wish to display two different segments of markup, depending on which type of item I'm displaying whilst iterative over my collection. Thanks!

Answer 1

I think a simple template filter here fits the best. It is really quick to implement and easy to call. Something like this:

in templatetags/my_filters.py:

from django import template
from django.utils.importlib import import_module

register = template.Library()

@register.filter
def isinst(value, class_str):
    split = class_str.split('.')
    return isinstance(value, getattr(import_module('.'.join(split[:-1])), split[-1]))

in your template:

{% load my_filters %}

...

{% if myvar|isinst:"mymodule.MyClass" %}
...do your stuff
{% endif %}

Although the above is a sample code (not tested), I believe it should work. For more information on custom template filters please see the django documentation

EDIT: Edited the answer to show that the filter argument is actually a string and not a python Class