How to authenticate in django using custom backend - django

Question

I am using django-mongoengine to use mongodb with django. I manually created a document containing user_data in user collection manually like this:
The user and django_session were created automatically when I integrated the module and ran the project
Now I tried to authenticate user like this:
def loginAction(request):
if request.is_ajax():
email = request.POST.get('email')
password = request.POST.get('password')
user = authenticate(email=email, password=password)
print user
if user:
if user.is_authenticated():
login(request, user)
return HttpResponse(json.dumps({'RESULT':'SUCCESS'}),content_type="application/json")
else:
return HttpResponse(json.dumps({'RESULT':'FAILURE'}),content_type="application/json")
However It is returning None when I am trying to print user.
I tried several codes but i am still not able to authenticate.
My settings.py :
INSTALLED_APPS = [
'django.contrib.admin',
'django.contrib.auth',
'django.contrib.contenttypes',
'django.contrib.sessions',
'django.contrib.messages',
'django.contrib.staticfiles',
'django_mongoengine',
'django_mongoengine.mongo_auth',
'login_app',
]
MONGODB_DATABASES = {
'default': {'name': 'picknbox'}
}
DATABASES = {
'default': {'ENGINE': 'django.db.backends.dummy'}
}
AUTH_USER_MODEL = 'mongo_auth.MongoUser'
AUTHENTICATION_BACKENDS = (
'django_mongoengine.mongo_auth.backends.MongoEngineBackend',
)
SESSION_ENGINE = 'django_mongoengine.sessions'
My question is how to authenticate using the django-mongoengine backend?
Note: I tried the same approach with sqlite database using custom backend and it worked. I was able to authenticate as well as login and logout was working fine.
EDIT: I checked the MongoEngineBackend class in AUTHENTICATION_BACKENDS and it is defined as:
from django.contrib import auth
class MongoEngineBackend(object):
"""Authenticate using MongoEngine and mongoengine.django.auth.User.
"""
supports_object_permissions = False
supports_anonymous_user = False
supports_inactive_user = False
authenticate = auth.backends.ModelBackend.__dict__["authenticate"]
get_user = auth.backends.ModelBackend.__dict__["get_user"]
so it uses the django's auth.