Django count in template on object attribute

Question

Here is a way to count objects in the django template:

{{ items|count }}

Is there a way to count objects with a certain boolean field attribute? Such as:

{{ items.boolean_field|count }} # sum([item.boolean_field for item in items])

Answer 1

Yes there is. Take a look at https://docs.djangoproject.com/en/1.7/howto/custom-template-tags/

You can create a filter. Something like:

@register.filter
def count_true(value):
    return value.filter(boolean_field=True).count()

And in your template:

{{ items|count_true }}