Allow use_for_related_fields via as_manager()

[Simon Litchfield]

The as_manager() method allows easy creation of chain-able managers. One of the most common use cases for these is with related fields. However, as_manager() doesn't currently allow use_for_related_fields to be specified. This patch proposes it could be set simply by way of an attribute on the QuerySet class, in the same way it currently does for Manager classes.

[Tim Graham]

ticket:24863#comment:10 might solve this. By the way, if you mean to propose a patch, I don't see it.

[Tim Graham]

I think the general idea is accepted even if the exact API needs to be worked out.

[Tim Graham]

Loic, can we close this in light of your PR to ​refactor manager inheritance (and deprecate use_for_related_fields)?

[Loic Bistuer]

Indeed, but maybe we should let the commit messages close this ticket? Not counting the chickens before they're hatched kinda thing?

[Loic Bistuer]

​PR6175 deprecates use_for_related_fields.

[Loïc Bistuer <loic.bistuer@…>]

In ed0ff91:

Fixed #10506, #13793, #14891, #25201 -- Introduced new APIs to specify models' default and base managers.

This deprecates use_for_related_fields.

Old API:

class CustomManager(models.Model):

use_for_related_fields = True

class Model(models.Model):

custom_manager = CustomManager()

New API:

class Model(models.Model):

custom_manager = CustomManager()

class Meta:

base_manager_name = 'custom_manager'

Refs #20932, #25897.

Thanks Carl Meyer for the guidance throughout this work.
Thanks Tim Graham for writing the docs.