Deficiencies in filtering for models.NullBooleanField

[rpkilby]

NullBooleanFields aren't completely supported by django-filter. By default, any generated fields will default to BooleanFilter, which only supports filtering by yes/no values, but not by null values. As documented in #522 (comment), this is now solvable in userland, but support could still be improved in-package.

[karlosss]

Shall take into account BooleanField(null=True) as well.

[rpkilby]

Thanks. Like you mentioned on SO - NullBooleanField will likely be deprecated at some point, so the solution here would need to account for both NullBooleanField and BooleanFields w/ null=True.

[alan404]

I have noticed that it was supported in django filter 1.x version by using 1, 2, 3 for null, false, and true respectively. After upgrading to 2.0 it has been changed to true / false but it is not stated in the "Migrating to 2.0" doc.

[karlosss]

Any reason for removing this feature?

[ses4j]

It's also true that NullBooleanField doesn't support true/false (though it supports True/False).