Authenticate user using email and password

Question

I have a form that only allow users to login via username . I decided to only allow user to login via email instead of username.

First, this is not a duplication of any

Answer 1

You can also write a custom backend:

# yourapp.backends.py    
from django.contrib.auth.models import User


class EmailOrUsernameModelBackend(object):
    """ Authenticate user by username or email """
    def authenticate(self, username=None, password=None):
        if '@' in username:
            kwargs = {'email': username}
        else:
            kwargs = {'username': username}
        try:

            user = User.objects.get(**kwargs)
            if user.check_password(password):
                return user
            else:
                return None
        except User.DoesNotExist:
            return None

    def get_user(self, user_id=None):
        try:
            return User.objects.get(pk=user_id)
        except User.DoesNotExist:
            return None

Now add your backend to settings.py:

AUTHENTICATION_BACKENDS = (
    'yourapp.backends.EmailOrUsernameModelBackend',
    'django.contrib.auth.backends.ModelBackend',
)