GM-67: Внедрить передачу флага нахождения заведения в избранном пользователя

apps/establishment/serializers.py

@@ -214,6 +214,16 @@ class EstablishmentDetailSerializer(EstablishmentListSerializer):
         return ReviewSerializer(obj.reviews.by_status(status=review_models.Review.READY)
                                            .order_by('-published_at').first()).data
 
+    def get_in_favorites(self, obj):
+        """Get in_favorites status flag"""
+        user = self.context.get('request').user
+        if user.is_authenticated:
+            return obj.id in user.favorites.by_content_type(app_label='establishment',
+                                                            model='establishment')\
+                                           .values_list('object_id', flat=True)
+        else:
+            return False
+
 
 class EstablishmentCommentCreateSerializer(comment_serializers.CommentSerializer):
     """Create comment serializer"""