feat-users-like-comments-163383199 (#48)

- users can like/dislike comments
- users can un-like/un-dislike comments
- users have to be authenticated to perfom like/dislike
- users cannot like their comments

[Starts #163383199]

authors/apps/articles/serializers.py

@@ -148,4 +148,4 @@ class ArticleReporterSerializer(serializers.ModelSerializer):
 
     class Meta:
         model = models.Report
-        fields = ('reporter', 'article', 'reason',)
+        fields = ('id', 'reporter', 'article', 'reason',)

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

@@ -17,12 +17,21 @@ class Migration(migrations.Migration):
         migrations.CreateModel(
             name='Comment',
             fields=[
-                ('id', models.AutoField(auto_created=True, primary_key=True, serialize=False, verbose_name='ID')),
+                ('id', models.AutoField(
+                    auto_created=True,
+                    primary_key=True,
+                    serialize=False, verbose_name='ID')),
                 ('body', models.TextField()),
                 ('created_at', models.DateTimeField(auto_now_add=True)),
-                ('updated_at', models.DateTimeField(auto_now=True, null=True)),
-                ('article', models.ForeignKey(on_delete=django.db.models.deletion.CASCADE, to='articles.Article')),
-                ('author', models.ForeignKey(on_delete=django.db.models.deletion.CASCADE, to='profiles.Profile')),
+                ('updated_at', models.DateTimeField(
+                    auto_now=True,
+                    null=True)),
+                ('article', models.ForeignKey(
+                    on_delete=django.db.models.deletion.CASCADE,
+                    to='articles.Article')),
+                ('author', models.ForeignKey(
+                    on_delete=django.db.models.deletion.CASCADE,
+                    to='profiles.Profile')),
             ],
             options={
                 'ordering': ['created_at'],
@@ -31,12 +40,18 @@ class Migration(migrations.Migration):
         migrations.CreateModel(
             name='CommentReply',
             fields=[
-                ('id', models.AutoField(auto_created=True, primary_key=True, serialize=False, verbose_name='ID')),
+                ('id', models.AutoField(
+                    auto_created=True, primary_key=True,
+                    serialize=False, verbose_name='ID')),
                 ('body', models.TextField()),
                 ('created_at', models.DateTimeField(auto_now_add=True)),
                 ('updated_at', models.DateTimeField(auto_now=True, null=True)),
-                ('author', models.ForeignKey(on_delete=django.db.models.deletion.CASCADE, to='profiles.Profile')),
-                ('comment', models.ForeignKey(on_delete=django.db.models.deletion.CASCADE, to='comments.Comment')),
+                ('author', models.ForeignKey(
+                    on_delete=django.db.models.deletion.CASCADE,
+                    to='profiles.Profile')),
+                ('comment', models.ForeignKey(
+                    on_delete=django.db.models.deletion.CASCADE,
+                    to='comments.Comment')),
             ],
             options={
                 'ordering': ['created_at'],

authors/apps/comments/migrations/0003_auto_20190220_0230.py

@@ -0,0 +1,29 @@
+# Generated by Django 2.1.5 on 2019-02-19 23:30
+
+from django.conf import settings
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        migrations.swappable_dependency(settings.AUTH_USER_MODEL),
+        ('comments', '0002_auto_20190211_1918'),
+    ]
+
+    operations = [
+        migrations.AddField(
+            model_name='comment',
+            name='disliked_by',
+            field=models.ManyToManyField(
+                related_name='disliked_comments',
+                to=settings.AUTH_USER_MODEL),
+        ),
+        migrations.AddField(
+            model_name='comment',
+            name='liked_by',
+            field=models.ManyToManyField(
+                related_name='liked_comments',
+                to=settings.AUTH_USER_MODEL),
+        ),
+    ]

authors/apps/comments/migrations/0004_merge_20190221_1355.py

@@ -0,0 +1,14 @@
+# Generated by Django 2.1.5 on 2019-02-21 10:55
+
+from django.db import migrations
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('comments', '0003_historicalcomment_historicalcommentreply'),
+        ('comments', '0003_auto_20190220_0230'),
+    ]
+
+    operations = [
+    ]

authors/apps/comments/migrations/0006_merge_20190222_1010.py

@@ -0,0 +1,14 @@
+# Generated by Django 2.1.5 on 2019-02-22 07:10
+
+from django.db import migrations
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('comments', '0005_historicalcomment_commenting_on'),
+        ('comments', '0004_merge_20190221_1355'),
+    ]
+
+    operations = [
+    ]

authors/apps/comments/models.py

@@ -19,6 +19,10 @@ class Comment(models.Model):
     author = models.ForeignKey(Profile, on_delete=models.CASCADE)
     article = models.ForeignKey(Article, on_delete=models.CASCADE)
     edit_history = HistoricalRecords()
+    liked_by = models.ManyToManyField(to=settings.AUTH_USER_MODEL,
+                                      related_name='liked_comments')
+    disliked_by = models.ManyToManyField(to=settings.AUTH_USER_MODEL,
+                                         related_name='disliked_comments')
 
     class Meta:
         """
@@ -37,6 +41,14 @@ def url(self):
         return settings.URL + reverse('comments:comment-details',
                                       kwargs={"pk": self.pk})
 
+    @property
+    def like_count(self):
+        return self.liked_by.count()
+
+    @property
+    def dislike_count(self):
+        return self.disliked_by.count()
+
 
 class CommentReply(models.Model):
     """The model defines the Comment-Replies table as stored in the DB

authors/apps/comments/serializers.py

@@ -25,6 +25,8 @@ class Meta:
             "article",
             "id",
             'commenting_on',
+            "like_count",
+            "dislike_count"
         )
         read_only_fields = (
             "article",

authors/apps/comments/signals.py

@@ -1,4 +1,5 @@
-from django.db.models.signals import post_save
+from django.db.models.signals import (
+    post_save, m2m_changed as model_field_changed_signal)
 from django.dispatch import receiver, Signal
 
 from authors.apps.comments.models import Comment
@@ -7,6 +8,9 @@
 # custom signal we shall send when a comment is published
 # the rationale for this custom signal is discussed in the articles app
 comment_published_signal = Signal(providing_args=["comment"])
+comment_liked_signal = Signal(
+    providing_args=["comment", "user_model", "id"]
+    )
 
 
 class CommentsSignalSender:
@@ -18,3 +22,21 @@ def on_comment_post_save(sender, **kwargs):
     if kwargs['created']:
         comment_published_signal.send(CommentsSignalSender,
                                       comment=kwargs['instance'])
+
+
+@receiver(model_field_changed_signal, sender=Comment.liked_by.through)
+def on_like_comment(sender, **kwargs):
+    """
+    on_like_comment is run when a user likes a comment. Then calls a signal
+    to notify the user
+    """
+    comment = kwargs.get("instance")
+    user_model = kwargs.get("model")
+    action = kwargs.get("action")
+    pk_set = kwargs.get("pk_set")
+    if action == "post_add":
+        user_id = [pk for pk in pk_set]
+        comment_liked_signal.send(CommentsSignalSender,
+                                  comment=comment,
+                                  user_model=user_model,
+                                  id=user_id[0])