Following complete.

conduit/apps/profiles/migrations/0002_profile_follows.py

@@ -0,0 +1,20 @@
+# -*- coding: utf-8 -*-
+# Generated by Django 1.10 on 2016-08-28 16:09
+from __future__ import unicode_literals
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+ dependencies = [
+ ('profiles', '0001_initial'),
+ ]
+
+ operations = [
+ migrations.AddField(
+ model_name='profile',
+ name='follows',
+ field=models.ManyToManyField(related_name='followed_by', to='profiles.Profile'),
+ ),
+ ]

conduit/apps/profiles/models.py

@@ -21,5 +21,32 @@ class Profile(TimestampedModel):
  # avatar. Similar to `bio`, this field is not required. It may be blank.
  image = models.URLField(blank=True)
 
+ # This is an example of a Many-To-Many relationship where both sides of the
+ # relationship are of the same model. In this case, the model is `Profile`.
+ # As mentioned in the text, this relationship will be one-way. Just because
+ # you are following mean does not mean that I am following you. This is
+ # what `symmetrical=False` does for us.
+ follows = models.ManyToManyField(
+ 'self',
+ related_name='followed_by',
+ symmetrical=False
+ )
+
  def __str__(self):
  return self.user.username
+
+ def follow(self, profile):
+ """Follow `profile` if we're not already following `profile`."""
+ self.follows.add(profile)
+
+ def unfollow(self, profile):
+ """Unfollow `profile` if we're already following `profile`."""
+ self.follows.remove(profile)
+
+ def is_following(self, profile):
+ """Returns True if we're following `profile`; False otherwise."""
+ return self.follows.filter(pk=profile.pk).exists()
+
+ def is_followed_by(self, profile):
+ """Returns True if `profile` is following us; False otherwise."""
+ return self.followed_by.filter(pk=profile.pk).exists()

conduit/apps/profiles/serializers.py

@@ -7,14 +7,29 @@ class ProfileSerializer(serializers.ModelSerializer):
  username = serializers.CharField(source='user.username')
  bio = serializers.CharField(allow_blank=True, required=False)
  image = serializers.SerializerMethodField()
+ following = serializers.SerializerMethodField()
 
  class Meta:
  model = Profile
- fields = ('username', 'bio', 'image',)
+ fields = ('username', 'bio', 'image', 'following',)
  read_only_fields = ('username',)
 
  def get_image(self, obj):
  if obj.image:
  return obj.image
 
  return 'https://static.productionready.io/images/smiley-cyrus.jpg'
+
+ def get_following(self, instance):
+ request = self.context.get('request', None)
+
+ if request is None:
+ return False
+
+ if not request.user.is_authenticated():
+ return False
+
+ follower = request.user.profile
+ followee = instance
+
+ return follower.is_following(followee)

conduit/apps/profiles/urls.py

@@ -1,7 +1,9 @@
 from django.conf.urls import url
 
-from .views import ProfileRetrieveAPIView
+from .views import ProfileRetrieveAPIView, ProfileFollowAPIView
 
 urlpatterns = [
  url(r'^profiles/(?P<username>\w+)/?$', ProfileRetrieveAPIView.as_view()),
+ url(r'^profiles/(?P<username>\w+)/follow/?$', 
+ ProfileFollowAPIView.as_view()),
 ]

conduit/apps/profiles/views.py

@@ -1,8 +1,9 @@
-from rest_framework import status
+from rest_framework import serializers, status
 from rest_framework.exceptions import NotFound
 from rest_framework.generics import RetrieveAPIView
-from rest_framework.permissions import AllowAny
+from rest_framework.permissions import AllowAny, IsAuthenticated
 from rest_framework.response import Response
+from rest_framework.views import APIView
 
 from .models import Profile
 from .renderers import ProfileJSONRenderer
@@ -23,6 +24,49 @@ def retrieve(self, request, username, *args, **kwargs):
  except Profile.DoesNotExist:
  raise NotFound('A profile with this username does not exist.')
 
- serializer = self.serializer_class(profile)
+ serializer = self.serializer_class(profile, context={
+ 'request': request
+ })
 
  return Response(serializer.data, status=status.HTTP_200_OK)
+
+
+class ProfileFollowAPIView(APIView):
+ permission_classes = (IsAuthenticated,)
+ renderer_classes = (ProfileJSONRenderer,)
+ serializer_class = ProfileSerializer
+
+ def delete(self, request, username=None):
+ follower = self.request.user.profile
+
+ try:
+ followee = Profile.objects.get(user__username=username)
+ except Profile.DoesNotExist:
+ raise NotFound('A profile with this username was not found.')
+
+ follower.unfollow(followee)
+
+ serializer = self.serializer_class(followee, context={
+ 'request': request
+ })
+
+ return Response(serializer.data, status=status.HTTP_200_OK)
+
+ def post(self, request, username=None):
+ follower = self.request.user.profile
+
+ try:
+ followee = Profile.objects.get(user__username=username)
+ except Profile.DoesNotExist:
+ raise NotFound('A profile with this username was not found.')
+
+ if follower.pk is followee.pk:
+ raise serializers.ValidationError('You can not follow yourself.')
+
+ follower.follow(followee)
+
+ serializer = self.serializer_class(followee, context={
+ 'request': request
+ })
+
+ return Response(serializer.data, status=status.HTTP_201_CREATED)