Django login with email and username

This is a simple solution to create costume logins with django.

Working in my project of SharePic, I realize that Instagram allows users to login with their username, email and phone number. So I challenge my self to achieve that without breaking the Django authentication structure. Searching about on the internet I found this post where they show how to create multiples login checks using the Django authentication. My implementation of that I summaries in the next steps.

First, add the authentication "backend" class in the "settings.py" that class has your login logic (login with email, log in with phone number, so on.).

...
AUTHENTICATION_BACKENDS = [
    'django.contrib.auth.backends.ModelBackend',
    'users.backends.EmailModelBackend'
]
...

In this case, I add the default "ModelBackend" which allows me to log in with username and "EmailModelBackend" which is my costume.

Second, create a python file "backends.py" in the "users" app with the class "EmailModelBackend". This class inherit from "ModelBackend" and re-write the method "authenticate" as is shown in the code.

# Django
from django.contrib.auth.backends import ModelBackend
# Models
from users.models import User

class EmailModelBackend(ModelBackend):
    """
    authentication class to login with the email address.
    """

    def authenticate(self, request, username=None, password=None, **kwargs):

        if '@' in username:
            kwargs = {'email': username}
        else:
            return None
        if password is None:
            return None
        try:
            user = User.objects.get(**kwargs)

        except User.DoesNotExist:
            User.set_password(password)

        else:
            if user.check_password(password) and self.user_can_authenticate(user):
                return user

I re-write the method base on the base code

Also, I create this unittest to make sure it's working properly:

"""Login views unit test"""

# Django
from django.test import TestCase, Client
from django.urls import reverse
# Models
from users.models import User


class TestLoginView(TestCase):
    """Test the functionality of the Login view"""
    def setUp(self):
        """Initialize variables."""
        self.client = Client()
        self.url = reverse('users:login')

    def test_basic_login_username(self):
        """Test basic login username"""
        response = self.client.post(reverse('users:signup'), {
            'username': 'john123',
            'password': '12345',
            'password_confirmation': '12345',
            'first_name': 'john',
            'last_name': 'smith',
            'email': 'john@smith.io'
        })

        self.assertEquals(response.status_code, 302)
        self.assertEquals(response.url, reverse('users:send_email_verification'))
        self.assertEquals(User.objects.get(username='john123').email, 'john@smith.io')

        response = self.client.post(self.url, {
            'username': 'john123',
            'password': '12345'
        })

        self.assertEquals(response.status_code, 302)
        self.assertIsNone(response.context)

    def test_basic_login_email(self):
        """Test basic login email"""
        response = self.client.post(reverse('users:signup'), {
            'username': 'john123',
            'password': '12345',
            'password_confirmation': '12345',
            'first_name': 'john',
            'last_name': 'smith',
            'email': 'john@smith.io'
        })

        self.assertEquals(response.status_code, 302)
        self.assertEquals(response.url, reverse('users:send_email_verification'))
        self.assertEquals(User.objects.get(username='john123').email, 'john@smith.io')

        response = self.client.post(self.url, {
            'username': 'john@smith.io',
            'password': '12345'
        })

        self.assertEquals(response.status_code, 302)
        self.assertIsNone(response.context)

To Have In mind:

• The Django authentication checks all the backends and which first allow to authenticate will use.
• The stronger of the system is equal at the weakest point.