Deprecate AllLookupsFilter in favor of Meta.fields '__all__'

[rpkilby]

Hi @philipn - wanted to get your opinion on deprecating AllLookupsFilter before a 1.0 release. We currently have two ways of exposing all lookups:

• some_field = filters.AllLookupsFilter()
• Meta.fields = {'some_field': '__all__'}

My thoughts on this:

• They are functionally identical for the end user
• This entire section of code is dedicated to supporting just AllLookupsFilter and requires duplicating some code from the main django_filters package.
• "There should be one obvious way to do it."

[rpkilby]

Actually, there are a couple of reasons:

• You can use AllLookupsFilter w/o Meta.fields or when Meta.fields is using the list syntax

• You can use AllLookupsFilter as part of a mixin filter. Meta option don't work as well for this case. eg

  class BaseFilter(filters.FilterSet):
      id = filters.AllLookupsFilter()
  
  class UserFilter(BaseFilter):
      class Meta:
          model = User

• AllLookupsFilter allows name aliasing

  class F(filters.FilterSet):
      pk = filters.AllLookupsFilter(name='id')

[jsmedmar]

The name aliasing feature is crucial... How could this be addressed using Meta.fields?

[rpkilby]

Yep - I realized this after the fact. See my second comment above. Definitely keeping AllLookupsFilter.