Multiple USERNAME_FIELD in django user model

Question

My custom user model:

class MyUser(AbstractBaseUser):
    username = models.CharField(unique=True,max_length=30)
    email = models.EmailField(unique=True,max_length=75)
    is_staff = models.IntegerField(default=False)
    is_active = models.IntegerField(default=False)
    date_joined = models.DateTimeField(default=None)

    # Use default usermanager
    objects = UserManager()

    USERNAME_FIELD = 'email'

Is there a way to specify multiple USERNAME_FIELD ? Something like ['email','username'] so that users can login via email as well as username ?

Answer 1

The USERNAME_FIELD setting does not support a list. You could create a custom authentication backend that tries to look up the user on the 'email' or 'username' fields.

from django.db.models import Q

from django.contrib.auth import get_user_model

MyUser = get_user_model()

class UsernameOrEmailBackend(object):
    def authenticate(self, username=None, password=None, **kwargs):
        try:
           # Try to fetch the user by searching the username or email field
            user = MyUser.objects.get(Q(username=username)|Q(email=username))
            if user.check_password(password):
                return user
        except MyUser.DoesNotExist:
            # Run the default password hasher once to reduce the timing
            # difference between an existing and a non-existing user (#20760).
            MyUser().set_password(password)

Then, in your settings.py set AUTHENTICATION_BACKENDS to your authentication backend:

 AUTHENTICATION_BACKENDS = ('path.to.UsernameOrEmailBackend,)\

Note that this solution isn't perfect. For example, password resets would only work with the field specified in your USERNAME_FIELD setting.