Flutter + Django OAuth integration

Question

I am using Flutter as front end and Django for back end purpose. I am trying to integrate Google and Facebook OAuth in the app and using some flutter libraires I am able to fetch user details and access token in front end. Now the question is how do I handle users and access tokens for them and verify them through drf. I could totally depend on drf for OAuth and create users using http request in front end using OAuth toolikt for Django but is there a way that I handle incoming auth tokens in front end and verify them in drf so as to register them in backend.

Solution

@api_view(http_method_names=['POST'])
@permission_classes([AllowAny])
@psa()
def exchange_token(request, backend):
    serializer = SocialSerializer(data=request.data)

    if serializer.is_valid(raise_exception=True):
        # This is the key line of code: with the @psa() decorator above,
        # it engages the PSA machinery to perform whatever social authentication
        # steps are configured in your SOCIAL_AUTH_PIPELINE. At the end, it either
        # hands you a populated User model of whatever type you've configured in
        # your project, or None.
        user = request.backend.do_auth(serializer.validated_data['access_token'])

        if user:
            # if using some other token back-end than DRF's built-in TokenAuthentication,
            # you'll need to customize this to get an appropriate token object
            token, _ = Token.objects.get_or_create(user=user)
            return Response({'token': token.key})

        else:
            return Response(
                {'errors': {'token': 'Invalid token'}},
                status=status.HTTP_400_BAD_REQUEST,
            )

There’s just a little more that needs to go in your settings (full code), and then you’re all set:

AUTHENTICATION_BACKENDS = (
    'social_core.backends.google.GoogleOAuth2',
    'social_core.backends.facebook.FacebookOAuth2',
    'django.contrib.auth.backends.ModelBackend',
)
for key in ['GOOGLE_OAUTH2_KEY',
            'GOOGLE_OAUTH2_SECRET',
            'FACEBOOK_KEY',
            'FACEBOOK_SECRET']:
    # Use exec instead of eval here because we're not just trying to evaluate a dynamic value here;
    # we're setting a module attribute whose name varies.
    exec("SOCIAL_AUTH_{key} = os.environ.get('{key}')".format(key=key))
SOCIAL_AUTH_PIPELINE = (
  'social_core.pipeline.social_auth.social_details',
  'social_core.pipeline.social_auth.social_uid',
  'social_core.pipeline.social_auth.auth_allowed',
  'social_core.pipeline.social_auth.social_user',
  'social_core.pipeline.user.get_username',
  'social_core.pipeline.social_auth.associate_by_email',
  'social_core.pipeline.user.create_user',
  'social_core.pipeline.social_auth.associate_user',
  'social_core.pipeline.social_auth.load_extra_data',
  'social_core.pipeline.user.user_details',
)

Add a mapping to this function in your urls.py, and you’re all set!