Override UserManager in django

Question

How can I use a custom manager for the auth_user class in django?

In my django project, I'm using auth_user and I have a basic profile class. In every page of my site, I use some user and profile data, so every user query should join profile.

I wanted to use select_related in the get_query_set() method in a custom manager, but I cannot find any proper way to define one, or to override the existing UserManager. Any ideas?

Note: I don't want to override the user model. Or, to be more precise, I already overrode it in different proxy models. I want this custom manager to be used in every proxy model.

Answer 1

Ok, finally found the correct answer. The cleanest way is to use a custom authentication backend.

# in settings:
AUTHENTICATION_BACKENDS = ('accounts.backends.AuthenticationBackend',)


# in accounts/backends.py:
from django.contrib.auth.backends import ModelBackend
from django.contrib.auth.models import User


class AuthenticationBackend(ModelBackend):
    def get_user(self, user_id):
        try:
            # This is where the magic happens
            return User.objects. \
                select_related('profile'). \
                get(pk=user_id)
        except User.DoesNotExist:
            return None