backend.py

from django.conf import settings
from django.contrib.auth import authenticate, login
from django.contrib.auth.models import User

from registration.backends.default import DefaultBackend
from registration.signals import user_registered

import commonware.log
log = commonware.log.getLogger(__name__)

class ExistingUserBackend(DefaultBackend):

    def post_registration_redirect(self, request, user):
        """
        Return the name of the URL to redirect to after successful
        user registration.

        """
        return ('account:registration_complete', (), {})

    def post_activation_redirect(self, request, user):
        """
        Return the name of the URL to redirect to after successful
        account activation.

        """
        return ('account:registration_activation_complete', (), {})

    def register(self, request, **kwargs):
        if (request.user.is_authenticated() and
                request.user.get_profile().is_registered()):
            log.info("User %s is already authenticating -- not registering",
                    request.user)
            return request.user

        email, password = kwargs['email'], kwargs['password1']
        log.info("Registering new user with email %s", email)
        user = User.objects.get_or_create(email=email,
                first_name=kwargs.get('first_name'),
                last_name=kwargs.get('last_name'))
        user.set_password(password)
        user.save()

        user = authenticate(username=user.username, password=password)
        login(request, user)
        user_registered.send(sender=self.__class__, user=user, request=request)
        return user

    def registration_allowed(self, request):
        allowed = getattr(settings, 'REGISTRATION_OPEN', True)
        if not allowed:
            return False
        if not getattr(settings, 'LIMITED_REGISTRATION', False):
            return True
        return self.check_access_token(request)

    def check_access_token(self, request):
        access_token = request.session.get('access_token', None)
        if access_token:
            # do what you need to do to validate the access token, return
            # True?False
            pass