Implement connect social accounts functionality

Add serializers and views for connecting accounts with minimal
specialization of the existing django-rest-auth interfaces.

Also add viewset which enables listing social account infmration
via the REST API for social authentication driven client applications.

Resolves #347 in GitHub.

Author: aleksihakli

docs/installation.rst

@@ -111,18 +111,23 @@ Facebook
 .. code-block:: python
 
     from allauth.socialaccount.providers.facebook.views import FacebookOAuth2Adapter
-    from rest_auth.registration.views import SocialLoginView
+    from rest_auth.registration.views import SocialLoginView, SocialConnectView
 
     class FacebookLogin(SocialLoginView):
         adapter_class = FacebookOAuth2Adapter
 
+    # Add a connect view if you want to allow connecting existing accounts
+    class FacebookConnect(SocialConnectView):
+        adapter_class = FacebookOAuth2Adapter
+
 4. Create url for FacebookLogin view:
 
 .. code-block:: python
 
     urlpatterns += [
         ...,
         url(r'^rest-auth/facebook/$', FacebookLogin.as_view(), name='fb_login')
+        url(r'^rest-auth/facebook/connect/$', FacebookConnect.as_view(), name='fb_connect')
     ]
 
 
@@ -136,20 +141,27 @@ If you are using Twitter for your social authentication, it is a bit different s
 .. code-block:: python
 
     from allauth.socialaccount.providers.twitter.views import TwitterOAuthAdapter
-    from rest_auth.views import LoginView
-    from rest_auth.social_serializers import TwitterLoginSerializer
+    from rest_auth.registration.views import SocialLoginView
+    from rest_auth.social_serializers import TwitterLoginSerializer, TwitterConnectSerializer
 
-    class TwitterLogin(LoginView):
+    class TwitterLogin(SocialLoginView):
         serializer_class = TwitterLoginSerializer
         adapter_class = TwitterOAuthAdapter
 
+    # Add a connect view if you want to allow connecting existing accounts
+    class TwitterConnect(SocialConnectView):
+        serializer_class = TwitterConnectSerializer
+        adapter_class = TwitterOAuthAdapter
+
+
 4. Create url for TwitterLogin view:
 
 .. code-block:: python
 
     urlpatterns += [
         ...,
         url(r'^rest-auth/twitter/$', TwitterLogin.as_view(), name='twitter_login')
+        url(r'^rest-auth/twitter/connect/$', TwitterConnect.as_view(), name='twitter_login')
     ]
 .. note:: Starting from v0.21.0, django-allauth has dropped support for context processors. Check out http://django-allauth.readthedocs.org/en/latest/changelog.html#from-0-21-0 for more details.
 

rest_auth/registration/serializers.py

@@ -14,10 +14,6 @@
 
 from rest_framework import serializers
 from requests.exceptions import HTTPError
-# Import is needed only if we are using social login, in which
-# case the allauth.socialaccount will be declared
-if 'allauth.socialaccount' in settings.INSTALLED_APPS:
-    from allauth.socialaccount.helpers import complete_social_login
 
 
 class SocialLoginSerializer(serializers.Serializer):
@@ -186,3 +182,44 @@ def save(self, request):
 
 class VerifyEmailSerializer(serializers.Serializer):
     key = serializers.CharField()
+
+
+# Import is needed only if we are using social login, in which
+# case the allauth.socialaccount will be declared
+if 'allauth.socialaccount' in settings.INSTALLED_APPS:
+    from allauth.socialaccount.helpers import complete_social_login
+    from allauth.socialaccount.models import SocialAccount
+    from allauth.socialaccount.providers.base import AuthProcess
+
+    class SocialAccountSerializer(serializers.ModelSerializer):
+        """
+        serialize allauth SocialAccounts for use with a REST API
+        """
+        class Meta:
+            model = SocialAccount
+            fields = (
+                'id',
+                'provider',
+                'uid',
+                'last_login',
+                'date_joined',
+                'extra_data',
+            )
+
+
+    class SocialConnectMixin(object):
+        def get_social_login(self, *args, **kwargs):
+            """
+            set the social login process state to connect rather than login
+
+            Refer to the implementation of get_social_login in base class and to the
+            allauth.socialaccount.helpers module complete_social_login function.
+            """
+
+            social_login = super(SocialConnectMixin, self).get_social_login(*args, **kwargs)
+            social_login.state['process'] = AuthProcess.CONNECT
+            return social_login
+
+
+    class SocialConnectSerializer(SocialConnectMixin, SocialLoginSerializer):
+        pass

rest_auth/registration/views.py

@@ -5,11 +5,13 @@
 
 from rest_framework.views import APIView
 from rest_framework.response import Response
-from rest_framework.permissions import AllowAny
+from rest_framework.permissions import (AllowAny,
+                                        IsAuthenticated)
+from rest_framework.decorators import detail_route
+from rest_framework.viewsets import GenericViewSet
 from rest_framework.generics import CreateAPIView
 from rest_framework import status
 
-from allauth.account.adapter import get_adapter
 from allauth.account.views import ConfirmEmailView
 from allauth.account.utils import complete_signup
 from allauth.account import app_settings as allauth_settings
@@ -19,7 +21,8 @@
                                     create_token)
 from rest_auth.models import TokenModel
 from rest_auth.registration.serializers import (SocialLoginSerializer,
-                                                VerifyEmailSerializer)
+                                                VerifyEmailSerializer,
+                                                SocialConnectSerializer)
 from rest_auth.utils import jwt_encode
 from rest_auth.views import LoginView
 from .app_settings import RegisterSerializer, register_permission_classes
@@ -91,31 +94,98 @@ def post(self, request, *args, **kwargs):
         return Response({'detail': _('ok')}, status=status.HTTP_200_OK)
 
 
-class SocialLoginView(LoginView):
-    """
-    class used for social authentications
-    example usage for facebook with access_token
-    -------------
-    from allauth.socialaccount.providers.facebook.views import FacebookOAuth2Adapter
+if 'allauth.socialaccount' in settings.INSTALLED_APPS:
+    from allauth.socialaccount import signals
+    from allauth.socialaccount.models import SocialAccount
+    from allauth.socialaccount.adapter import get_adapter
 
-    class FacebookLogin(SocialLoginView):
-        adapter_class = FacebookOAuth2Adapter
-    -------------
+    from rest_auth.registration.serializers import SocialAccountSerializer
 
-    example usage for facebook with code
 
-    -------------
-    from allauth.socialaccount.providers.facebook.views import FacebookOAuth2Adapter
-    from allauth.socialaccount.providers.oauth2.client import OAuth2Client
+    class SocialLoginView(LoginView):
+        """
+        class used for social authentications
+        example usage for facebook with access_token
+        -------------
+        from allauth.socialaccount.providers.facebook.views import FacebookOAuth2Adapter
 
-    class FacebookLogin(SocialLoginView):
-        adapter_class = FacebookOAuth2Adapter
-         client_class = OAuth2Client
-         callback_url = 'localhost:8000'
-    -------------
-    """
+        class FacebookLogin(SocialLoginView):
+            adapter_class = FacebookOAuth2Adapter
+        -------------
 
-    serializer_class = SocialLoginSerializer
+        example usage for facebook with code
 
-    def process_login(self):
-        get_adapter(self.request).login(self.request, self.user)
+        -------------
+        from allauth.socialaccount.providers.facebook.views import FacebookOAuth2Adapter
+        from allauth.socialaccount.providers.oauth2.client import OAuth2Client
+
+        class FacebookLogin(SocialLoginView):
+            adapter_class = FacebookOAuth2Adapter
+            client_class = OAuth2Client
+            callback_url = 'localhost:8000'
+        -------------
+        """
+
+        serializer_class = SocialLoginSerializer
+
+        def process_login(self):
+            get_adapter(self.request).login(self.request, self.user)
+
+
+    class SocialConnectView(SocialLoginView):
+        """
+        class used for social account linking
+
+        example usage for facebook with access_token
+        -------------
+        from allauth.socialaccount.providers.facebook.views import FacebookOAuth2Adapter
+
+        class FacebookConnect(SocialConnectView):
+            adapter_class = FacebookOAuth2Adapter
+        -------------
+        """
+
+        serializer_class = SocialConnectSerializer
+        permission_classes = (IsAuthenticated,)
+
+
+    class SocialAccountViewSet(GenericViewSet):
+        """
+        allauth SocialAccount REST API read and disconnect views for logged in users
+
+        Refer to the django-allauth package implementation of the models and
+        account handling logic for more details, this viewset emulates the allauth web UI.
+        """
+
+        serializer_class = SocialAccountSerializer
+        permission_classes = (IsAuthenticated,)
+        queryset = SocialAccount.objects.none()
+
+        def get_queryset(self):
+            return SocialAccount.objects.filter(user=self.request.user)
+
+        def list(self, request):
+            """
+            list SocialAccounts for the currently logged in user
+            """
+
+            return Response(self.get_serializer(self.get_queryset(), many=True).data)
+
+        @detail_route(methods=['POST'])
+        def disconnect(self, request, pk):
+            """
+            disconnect SocialAccount from remote service for the currently logged in user
+            """
+
+            accounts = self.get_queryset()
+            account = accounts.get(pk=pk)
+            get_adapter(self.request).validate_disconnect(account, accounts)
+
+            account.delete()
+            signals.social_account_removed.send(
+                sender=SocialAccount,
+                request=self.request,
+                socialaccount=account
+            )
+
+            return Response(self.get_serializer(account).data)