Error importing RegistrationView when using custom user model with unique USERNAME_FIELD about django-registration

[ubernostrum]

I've thought about this a lot, and I think the only way forward is to finally just give up on using Django's UserCreationForm.

That's a backwards-incompatible change, so I can't do it immediately, but once I get a release out for official Django 4.2 compatibility I'll start on a major version bump branch that will ship its own base form that doesn't hard-wire in the default Django User model.

[ubernostrum]

I need to think about this one.

[kbarnes3]

I was able to work around this by setting my EmailField to be named username. This wasn't too difficult since I'm trying to incorporate Django-Registration into a new project that hasn't been deployed yet, but I imagine it would be more difficult for established sites to do this.

[ubernostrum]

The thing that's worrying me here is that there's no such thing as a truly generic user-registration view/form for Django. The amount of stuff you can do in a custom user model just makes it impossible to write a single form that can handle anything someone might do. And the documentation on using a custom user model with django-registration already makes clear that there are times when you're going to have to write your own stuff rather than be able to use simple subclasses of the built-in forms/views.

So I'm leaning toward just doing a better job of documenting what django-registration can support, and maybe better documentation of what you need to do when your user model gets too different from that.

[kbarnes3]

I think a big problem with this issue is that the errors occur on import time. As it is structured now, not only do I have to write my own form, but I can't use the RegistrationView (because I can't import it) nor the URLs (because those import the RegistrationView as well). It would be nice if these errors could be deferred in some way to when the impacted classes are instantiated or something similar.

[confuzeus]

Why not use get_user_model in the RegistrationForm? I just submitted a PR for that but don't know if I'm missing a case where not using Django's default might break someone's code.

[ubernostrum]

Yeah, the issue is that UserCreationForm has defaulted to the built-in User forever, and I don't even know how much stuff depends on it.

If it's going to change, it'll have to change in a major version bump. I'm thinking through whether I want to do that to cover this case, since it's one that comes up but not super often, and the case of differing significantly from Django's built-in model is already one that has a lot of warnings in the docs.