Template filter "slice" raises TypeError on bound RadioSelect

[Jon Dufresne]

I have a template with the following snippet:

{% for choice in form.choices|slice:'1:' %}
    <li>{{ choice }}</li>
{% endfor %}

Where choices is a ChoiceField with a RadioSelect widget. This stopped working in 1.8.

Looking through the code history, this looks like it was introduce in commit ​5e06fa14 during work on ticket #22745.

The change to BoundField.__getitem__():

      def __getitem__(self, idx):
+        # Prevent unnecessary reevaluation when accessing BoundField's attrs
+        # from templates.
+        if not isinstance(idx, six.integer_types):
+            raise TypeError
         return list(self.__iter__())[idx]

It no longer accepts a slice and will instead raise a TypeError.

[Jon Dufresne]

​https://github.com/django/django/pull/6184

[Jon Dufresne]

Moved PR <​https://github.com/django/django/pull/6185>.

[Tim Graham <timograham@…>]

In b412681:

Fixed #26267 -- Fixed BoundField to reallow slices of subwidgets.

[Tim Graham <timograham@…>]

In 04780e8a:

[1.9.x] Fixed #26267 -- Fixed BoundField to reallow slices of subwidgets.

Backport of b41268135995cef46d40e550f9301fab20cf330d from master

[Tim Graham <timograham@…>]

In 6c48eda:

[1.8.x] Fixed #26267 -- Fixed BoundField to reallow slices of subwidgets.

Backport of b41268135995cef46d40e550f9301fab20cf330d from master