Adjusted token admin to map to user ID.

[carltongibson]

Closes #6131.

• Adds a proxy model for Token that uses the user.pk, rather than it's own.
• Adjusts Admin to map back from User ID to token instance.

Proof of concept. Works but...

• Needs some unit tests.
• Could do with testing against a custom user model.

Thoughts?

[lovelydinosaur]

Righty, tested this all locally, both with a standard user model, and with a custom user model.
Looks great, let's do it!

[kalekseev]

Django complains about TokenProxy "TypeError: Abstract base class containing model fields not permitted for proxy model 'TokenProxy'.", Token is abstract model if the app is not installed

[carltongibson]

@kalekseev "If the app is not installed" -- what does that mean exactly? (Is "install it" an appropriate fix?)

Probably need a new issue with an example project.

[kalekseev]

@carltongibson sorry for the lack of details I was from mobile. Basically Token become abstract if 'rest_framework.authtoken' not in settings.INSTALLED_APPS https://github.com/encode/django-rest-framework/blob/master/rest_framework/authtoken/models.py#L26. In my case rest_auth app importing rest_framework.authtoken.models but it's not used in my project so it's not in installed apps. Same thing will happen if someone needs a CustomToken that extends Token in that case he wants Token model to be abstract.

[carltongibson]

So we could maybe fix this making proxy depend on the same conditional...?

Would you be up for adding a PR for that?

[kalekseev]

@carlfarrington I have discovered that problem developing this pr #7438 and I don't have that much free time right now to commit myself to one more.

[carltongibson]

Ok, in that case, can I ask you to open a new issue, so this doesn't get lost in the cracks? Thanks!