feat(like-dislike): Like and Dislike Articles.

- Allow a user to like and unlike  an article.
- Allow a user to dislike and un-dislike an article.
- Allow user to turn like to dislike and reverse.

[starts #162949220]

authors/apps/articles/migrations/0001_initial.py

@@ -1,11 +1,5 @@
-<<<<<<< HEAD
-# Generated by Django 2.1.4 on 2019-01-25 15:01
+# Generated by Django 2.1.4 on 2019-01-28 09:25
 
-=======
-# Generated by Django 2.1.4 on 2019-01-22 05:48
-
-import cloudinary.models
->>>>>>> feat(articles): user can create articles
 from django.conf import settings
 from django.db import migrations, models
 import django.db.models.deletion
@@ -17,37 +11,34 @@ class Migration(migrations.Migration):
 
     dependencies = [
         migrations.swappable_dependency(settings.AUTH_USER_MODEL),
+        ('contenttypes', '0002_remove_content_type_name'),
     ]
 
     operations = [
         migrations.CreateModel(
-<<<<<<< HEAD
             name='Article',
             fields=[
                 ('id', models.AutoField(auto_created=True, primary_key=True, serialize=False, verbose_name='ID')),
                 ('slug', models.SlugField(blank=True, max_length=253)),
-=======
-            name='Articles',
-            fields=[
-                ('id', models.AutoField(auto_created=True, primary_key=True, serialize=False, verbose_name='ID')),
-                ('slug', models.SlugField(blank=True, max_length=253, unique=True)),
-                ('image', cloudinary.models.CloudinaryField(default='', max_length=255, verbose_name='image')),
->>>>>>> feat(articles): user can create articles
                 ('title', models.CharField(max_length=100)),
                 ('description', models.CharField(max_length=230)),
                 ('body', models.TextField()),
                 ('created_at', models.DateTimeField(auto_now_add=True)),
-<<<<<<< HEAD
-                ('updated_at', models.DateTimeField(auto_now=True)),
+                ('updated_at', models.DateField(auto_now=True)),
                 ('author', models.ForeignKey(on_delete=django.db.models.deletion.CASCADE, related_name='author', to=settings.AUTH_USER_MODEL)),
             ],
             options={
                 'ordering': ['-created_at'],
             },
-=======
-                ('updated_at', models.DateField(auto_now=True)),
-                ('author', models.OneToOneField(on_delete=django.db.models.deletion.CASCADE, related_name='author', to=settings.AUTH_USER_MODEL)),
+        ),
+        migrations.CreateModel(
+            name='LikeDislike',
+            fields=[
+                ('id', models.AutoField(auto_created=True, primary_key=True, serialize=False, verbose_name='ID')),
+                ('vote', models.BooleanField(choices=[(False, 'Dislike'), (True, 'Like')], verbose_name='vote')),
+                ('object_id', models.PositiveIntegerField()),
+                ('author', models.ForeignKey(on_delete=django.db.models.deletion.CASCADE, to=settings.AUTH_USER_MODEL)),
+                ('content_type', models.ForeignKey(on_delete=django.db.models.deletion.CASCADE, to='contenttypes.ContentType')),
             ],
->>>>>>> feat(articles): user can create articles
         ),
     ]

authors/apps/articles/models.py

@@ -1,19 +1,53 @@
+from django.contrib.contenttypes.fields import GenericRelation, \
+    GenericForeignKey
+from django.contrib.contenttypes.models import ContentType
 from django.db import models
 from .utils import get_unique_slug
 from django.db.models.signals import pre_save
-from django.db import models
-from cloudinary.models import CloudinaryField
-from .utils import get_unique_slug
 
 # local imports
 from ..authentication.models import User
-
 """
     Articles
 """
 
 
-# Create your models here.
+class LikeDislikeManager(models.Manager):
+    """This is model manager for likes and dislikes data"""
+
+    def likes(self):
+        """
+        get all the likes for an object
+        """
+        return self.get_queryset().filter(vote=True)
+
+    def dislikes(self):
+        """
+        get all the dislikes for an object
+        """
+        return self.get_queryset().filter(vote=False)
+
+
+class LikeDislike(models.Model):
+    """This class defines data for the likes and dislikes."""
+
+    LIKE = True
+    DISLIKE = False
+
+    VOTES = (
+        (DISLIKE, 'Dislike'),
+        (LIKE, 'Like')
+    )
+
+    vote = models.BooleanField(verbose_name='vote', choices=VOTES)
+    author = models.ForeignKey(User, on_delete=models.CASCADE)
+    content_type = models.ForeignKey(ContentType, on_delete=models.CASCADE)
+    object_id = models.PositiveIntegerField()
+    content_object = GenericForeignKey()
+
+    objects = LikeDislikeManager()
+
+
 class Article(models.Model):
     slug = models.SlugField(max_length=253, blank=True)
     author = models.ForeignKey(User, on_delete=models.CASCADE,
@@ -22,8 +56,8 @@ class Article(models.Model):
     description = models.CharField(max_length=230, blank=False)
     body = models.TextField(blank=False)
     created_at = models.DateTimeField(auto_now_add=True)
-    updated_at = models.DateTimeField(auto_now=True)
-
+    updated_at = models.DateField(auto_now=True)
+    votes = GenericRelation(LikeDislike, related_query_name='articles')
 
     def __str__(self):
         return str(self.title)
@@ -51,3 +85,6 @@ class Meta:
 def slug_pre_save_receiver(sender, instance, *args, **kwargs):
     if not instance.slug:
         instance.slug = get_unique_slug(instance, 'title', 'slug')
+
+
+pre_save.connect(slug_pre_save_receiver, sender=Article)

authors/apps/articles/renderers.py

@@ -1,10 +1,12 @@
 import json
 from rest_framework.renderers import JSONRenderer
 from rest_framework.utils.serializer_helpers import ReturnList
+import json
 
 
 class ArticleJSONRenderer(JSONRenderer):
     charset = 'utf-8'
+
     def render(self, data, media_type=None, renderer_context=None):
         if isinstance(data, ReturnList):
             return json.dumps({
@@ -24,3 +26,12 @@ def render(self, data, media_type=None, renderer_context=None):
             'comment': data,
             'commentsCount': len(data)
         })
+
+
+class LikeArticleJSONRenderer(JSONRenderer):
+    charset = 'utf-8'
+
+    def render(self, data, media_type=None, renderer_context=None):
+        return json.dumps({
+            'likes_dislikes': data
+        })

authors/apps/articles/serializers.py

@@ -2,6 +2,7 @@
 
 from .models import Article, Comments
 from authors.apps.profiles.models import UserProfile
+from .models import Article, LikeDislike
 from authors.apps.profiles.serializers import ProfileSerialiazer
 
 
@@ -120,3 +121,9 @@ class Meta:
             'article',
             'parent',
         )
+
+
+class LikeDislikeSerializer(serializers.ModelSerializer):
+
+    class Meta:
+        model = LikeDislike

authors/apps/articles/urls.py

@@ -1,26 +1,33 @@
-
 from django.urls import path
 
 from authors.apps.articles.views.comments import(
     CommentsListView,
     CommentsRetrieveUpdateDestroy
 )
 from authors.apps.articles.views.articles import (GetUpdateDeleteArticle,
-                                                  CreateArticleView)
+                                                  CreateArticleView,
+                                                  LikeDislikeArticleView)
+from authors.apps.articles.models import Article, LikeDislike
 
 """
 Django 2.0 requires the app_name variable set when using include namespace
 """
 app_name = 'articles'
 
 urlpatterns = [
-
     path('', CreateArticleView.as_view(),
          name='article_create'),
     path('/<slug:slug>', GetUpdateDeleteArticle.as_view(),
          name='detail_article'),
     path('/<slug>/comments', CommentsListView.as_view(), name='comment'),
     path('/<slug>/comments/<int:id>',
          CommentsRetrieveUpdateDestroy.as_view(), name='thread'
-         )
+         ),
+    path('', CreateArticleView.as_view(), name='article-create'),
+    path('/<slug>/like',
+         LikeDislikeArticleView.as_view(vote_type=LikeDislike.LIKE),
+         name='article-like-like'),
+    path('/<slug>/dislike',
+         LikeDislikeArticleView.as_view(vote_type=LikeDislike.DISLIKE),
+         name='article-like-dislike'),
 ]

authors/apps/articles/views/articles.py

@@ -6,14 +6,16 @@
 )
 from rest_framework.response import Response
 from rest_framework.views import status
+from django.shortcuts import get_object_or_404
+from django.contrib.contenttypes.models import ContentType
 
 # local imports
-from authors.apps.articles.models import Article
+from authors.apps.articles.models import Article, LikeDislike
 from authors.apps.articles.serializers import (
-    ArticleSerializer, UpdateArticleSerializer
+    ArticleSerializer, UpdateArticleSerializer, LikeDislikeSerializer
 )
 
-from authors.apps.articles.renderers import ArticleJSONRenderer
+from authors.apps.articles.renderers import ArticleJSONRenderer, LikeArticleJSONRenderer
 from authors.apps.articles.response_messages import (error_messages,
                                                      success_messages)
 
@@ -129,3 +131,50 @@ def delete(self, request, *args, **kwargs):
         article.delete()
         message = success_messages['deleted']
         return Response(message, status=status.HTTP_200_OK)
+
+
+class LikeDislikeArticleView(ListCreateAPIView):
+    permission_classes = (IsAuthenticated,)
+    serializer_class = LikeDislikeSerializer
+    renderer_classes = (LikeArticleJSONRenderer,)
+    vote_type = None
+
+    def post(self, request, slug):
+        """""This method posts likes and dislikes"""
+
+        article = get_object_or_404(Article, slug=slug)
+
+        # message to display after like or dislike
+        try:
+            like_dislike = LikeDislike.objects.get(
+                content_type=ContentType.objects.get_for_model(article),
+                author=request.user,
+                object_id=article.id)
+            if like_dislike.vote is not self.vote_type:
+                like_dislike.vote = self.vote_type
+                like_dislike.save(update_fields=['vote'])
+            else:
+                like_dislike.delete()
+        except LikeDislike.DoesNotExist:
+            article.votes.create(author=request.user, vote=self.vote_type)
+            article.save()
+
+        return Response({
+            "likes": article.votes.likes().count(),
+            "dislikes": article.votes.dislikes().count(),
+                },
+                content_type="application/json",
+                status=status.HTTP_201_CREATED
+            )
+
+    def get(self, request, slug):
+
+        article = get_object_or_404(Article, slug=slug)
+
+        return Response({
+            "likes": article.votes.likes().count(),
+            "dislikes": article.votes.dislikes().count(),
+                },
+                content_type="application/json",
+                status=status.HTTP_200_OK
+            )