Re-add conditional abstract setting to Token model

[adam-thomas]

When attempting to use a custom model instead of DRF's built-in Token, Django tries very hard to include the Token model even if rest_framework.authtoken isn't in INSTALLED_APPS. Attempting to run migrations on a fresh database will explode with a missing user model error, and an already-set-up database will have a Token table added to it (which also means the user model gets an unwanted auth_token OneToOne field on it).

I believe a simple fix for this behaviour is to reinstate the Meta abstract setting in the Token model. I spent a day or so digging for other ways to avoid using Token in the project I was working on and couldn't find anything, but there may also be other fixes.

[xordoquy]

Should be fixed by #3785

[adam-thomas]

Unfortunately, that's the exact commit that introduces the breakage. The delayed import doesn't seem to help. I haven't been able to figure out why.

[adam-thomas]

When I was experimenting and trying to figure out how to work around this, I even deleted the entire TokenAuthentication class, and the problem persisted. I think the Token model is being picked up through other means.

[adam-thomas]

(We're on Django 1.8.)

[xordoquy]

Do you have some sample project to reproduce the issue ?

[adam-thomas]

Not at the moment (it's a private project). I'll try to get some time to make one. I imagine it would involve:

• rest_framework in INSTALLED_APPS (but not rest_framework.authtoken)
• A User model exists and AUTH_USER_MODEL is set
• A test calls _meta.get_all_field_names() on that user model

I don't know if the migration ordering issue will occur for the test project - it depends on whether Token is migrated before User. If it does, trying to run the tests will blow up with the SQL error about a missing relation. If that error doesn't appear, the test should show that auth_token is a field on the User model.

[xordoquy]

Now that I read this again, I think I get the issue and indeed the Token should be left abstract if the app isn't in the INSTALLED_APPS.

[adam-thomas]

👍 Thanks :)

[jpadilla]

@xordoquy so we keep #3785 and just revert the changes to the Meta class on the model?

[xordoquy]

Yup, that's #3860

[xordoquy]

@adam-thomas thanks for pointing this to our attention.

[adam-thomas]

Thank you @xordoquy :)

[adam-thomas]

And, most welcome! Glad to help!

[tomchristie]

👍