Add "field" to the context when rendering widgets.

[Jacob Rief]

Unsure if this shall be a feature request, but I noticed that when rendering a field label, the template's rendering context additionally contains the field- and the form-object. If however, I render the widget itself, this information is not available inside the widget's template rendering context. Apart from this inconsistency, being able to access the field- and/or the form-object, when rendering a widget is really useful.

Example:
I would like to use the form-attribute inside some <input …>-widgets, so that each field can refer to its corresponding form. See ​https://developer.mozilla.org/en-US/docs/Web/HTML/Element/input#attr-form for details. The form-object itself provides a name, which is used as the <form id="…" …>. Therefore each widget has to know their form's name. This information currently can not be determined inside the widget's template.

[Claude Paroz]

Note that form is no longer in the context after #33134.

[Jacob Rief]

Well, in case of the label rendering context, the form-object is accessible through the field. However, the widget rendering context doesn't offer the field-object.

[Mariusz Felisiak]

Tentatively accepted, this will require passing field to the Widget.render().

This is not strictly related with 456466d932830b096d39806e291fe23ec5ed38d5.

[Jacob Rief]

Here is a draft pull request to implement this:
​https://github.com/django/django/pull/14955

[David Smith]

I wonder about creating a circular context here. A field has a widget and you can access the field from the context of the widget and so on. See #33134 for a recent bug with field labels.

[Mariusz Felisiak]

This should be review again.

[Carlton Gibson]

As per David's comment on the PR here, we should resolve #34077 first, to see if that gives everything needed here.

[Mariusz Felisiak]

Marking as "Patch needs improvement" as this is waiting for #34077.

[Mariusz Felisiak]

Jacob, Have you seen cad376f844c7bdeeee7607a7c0ea8ae52061309b? Do we still need this change?

[Mariusz Felisiak]

I think it's no longer needed after cad376f844c7bdeeee7607a7c0ea8ae52061309b.