Django custom login issue - python-3.x

Question

I have created a custom authenticate method because instead of username I want to log in through email for that I have written backends.py
backends.py
from django.contrib.auth import get_user_model
from django.core.exceptions import ValidationError
UserModel = get_user_model()
class EmailBackend(object):
def authenticate(username=None,password=None):
try:
user = UserModel.objects.get(email=username)
if user.check_password(password):
return user
else:
return None
except UserModel.DoesNotExist:
raise ValidationError('Invalid Credentials')
def get_user(self,user_id):
try:
return UserModel.objects.get(pk=user_id)
except UserModel.DoesNotExist:
return None
After authenticating i want user to be logged in.For that i am using login method as below:
login(request,user,backend='django.contrib.auth.backends.ModelBackend')
views.py
from django.shortcuts import render,redirect
from users.forms import RegisterForm,LoginForm
from users.backends import EmailBackend as em
from django.contrib import messages
from django.contrib.auth.decorators import login_required
from django.contrib.auth import login
def register(request):
if request.method=='POST':
form = RegisterForm(request.POST)
if form.is_valid():
form.save()
print('Successfully Created')
else:
form = RegisterForm()
return render(request,'users/register.html',{'form':form})
def user_login(request):
if request.method == 'POST':
form = LoginForm(request.POST)
uname = request.POST['username']
pwd = request.POST['password']
user = em.authenticate(username=uname,password=pwd)
if user is not None:
if user.is_active==True:
k=login(request,user,backend='django.contrib.auth.backends.ModelBackend')
print(user,k)
print('Successfull login')
else:
print('Unsuccessfull login')
else:
form = LoginForm()
return render(request,'users/login.html',{'form':form})
In my console, I am trying to get the value returned by the login function but that is returning None .
k=login(request,user,backend='django.contrib.auth.backends.ModelBackend')
print(user,k)
Output in my console:
[16/Mar/2021 16:02:34] "POST /register/ HTTP/1.1" 200 881
[16/Mar/2021 16:02:52] "GET /login/ HTTP/1.1" 200 705
testuser#gmail.com None
Successfull login
[16/Mar/2021 16:02:58] "POST /login/ HTTP/1.1" 302 0
[16/Mar/2021 16:02:58] "GET /home HTTP/1.1" 200 237**
Print method is giving the correct value of user but for k it is giving None. That means the login function is not working and that means login authentication is not working properly.
How can I do login once authenticate method is returned, user? In which way login can be successful.
My code:
settings.py
AUTHENTICATION_BACKENDS = ['django.contrib.auth.backends.ModelBackend',
'users.backends.EmailBackend']
models.py
from django.db import models
from django.contrib.auth.models import AbstractBaseUser,AbstractUser
from django.utils.translation import gettext_lazy as _
class CustomUser(AbstractBaseUser):
email = models.EmailField(_('email address'), unique=True)
last_login = models.DateTimeField(verbose_name='last login', auto_now=True)
is_superuser = models.BooleanField(default=False)
is_active = models.BooleanField(default=True)
is_staff = models.BooleanField(default=False)
date_joined = models.DateTimeField(verbose_name='date joined', auto_now_add=True)
USERNAME_FIELD='email'
forms.py
from django.contrib.auth import get_user_model
from django.contrib.auth.forms import UserCreationForm, AuthenticationForm
from django import forms
from users.models import CustomUser
class RegisterForm(UserCreationForm):
class Meta():
model = get_user_model()
fields = ('email', 'password1', 'password2')
class LoginForm(AuthenticationForm):
class Meta():
model = get_user_model()

Answer 1

You are doing you login wrong. You are referencing the auth Backend you just overwrote.
In your login function, do
login(request, user)
And in your settings
AUTHENTICATION_BACKENDS = ['users.backends.EmailBackend', 'django.contrib.auth.backends.ModelBackend']
One more thing, do not import your backend. Just import django authenticate module like you would do if weren't having your own backend
And change your authenticate line to
From django.contrib.auth import authenticate
user = authenticate(username=uname, password=pwd)

Answer 2

I got the answer login method has no return value that's why it is returning None. Once authenticate method is executed it will return a user if credentials are valid . After that login method will make you logged in.