Add an admin filter with choices "all", "blank", "not blank"

[Jonas Haag]

Add a new admin filter that allows to show only objects with a blank (or non-blank) field value. Shows three options "all", "blank", "not blank".

This is something I've regularly required and there doesn't seem to be any third party package implementing this, but there are at least a few other people having the need: ​https://stackoverflow.com/questions/37799694/django-admin-list-filter-filter-field-by-is-empty-none-or-empty-string ​https://gist.github.com/haplo/2695675 Note that while the filter could easily live in a third party package, I think it makes sense to include it in Django. It's not much code and I guess it's a common requirement.

[Jonas Haag]

PR ​https://github.com/django/django/pull/9546

[Tim Graham]

Duplicate of #28687?

[Jonas Haag]

Not exactly here we're looking at

• a new filter for
• blank values
• of any kind of field (not necessarily relation fields)

#28687 is looking at

• an extension of an existing filter
• of null values
• that deals with relation fields

[Christophe Baldy]

Hi,

I tried to rework and improve the original PR with my own PR ​https://github.com/django/django/pull/10599

(This my first attempt to contribute to Django)

Thanks

[Simon Charette]

Left a few comments for improvements on the PR.

[Carlton Gibson]

Commented on PR: Docs need some clarification. Possibly some extra tests needed. (?) Needs updating to target v3.0.

[Federico Jaramillo Martínez]

PR ​https://github.com/django/django/pull/12239

[Mariusz Felisiak <felisiak.mariusz@…>]

In 372eaa39:

Fixed #28991 -- Added EmptyFieldListFilter class in admin.filters.

Thanks Simon Charette and Carlton Gibson for reviews.

Co-Authored-By: Jonas Haag <jonas@…>
Co-Authored-By: Christophe Baldy <christophe.baldy@…>