feature(paginate articles): Pagination support for articles.

- Enable users to paginate articles [Finishes #159952015] Co-authored-by: huxaiphaer <huxaiphaeridris@gmail.com> Co-authored-by: reiosantos <ronireiosantos@gmail.com>
andela · Sep 14, 2018 · ea62c3d · ea62c3d
1 parent 4f71a57
commit ea62c3d
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Showing 6 changed files with 53 additions and 39 deletions.
diff --git a/authors/apps/articles/migrations/0001_initial.py b/authors/apps/articles/migrations/0001_initial.py
@@ -1,13 +1,17 @@
-# Generated by Django 2.1 on 2018-09-13 09:42
+# Generated by Django 2.1 on 2018-09-14 07:51
 
+from django.conf import settings
 from django.db import migrations, models
+import django.db.models.deletion
 import django.utils.timezone
 
 
 class Migration(migrations.Migration):
+
     initial = True
 
     dependencies = [
+        migrations.swappable_dependency(settings.AUTH_USER_MODEL),
     ]
 
     operations = [
@@ -26,6 +30,7 @@ class Migration(migrations.Migration):
                 ('favorited', models.BooleanField(default=False)),
                 ('favorites_count', models.IntegerField(default=0)),
                 ('photo_url', models.CharField(max_length=255, null=True)),
+                ('author', models.ForeignKey(on_delete=django.db.models.deletion.CASCADE, to=settings.AUTH_USER_MODEL)),
             ],
             options={
                 'ordering': ['-created_at', 'author'],

diff --git a/authors/apps/articles/migrations/0002_article_author.py b/authors/apps/articles/migrations/0002_article_author.py
diff --git a/authors/apps/articles/renderer.py b/authors/apps/articles/renderer.py
@@ -20,16 +20,16 @@ def render(self, data, accepted_media_type=None, renderer_context=None):
         :param renderer_context:
         :return:
         """
-        if isinstance(data, list) and len(data) > 1:
+        val = data.get("results", None)
+        if val and isinstance(val, list) and len(val) > 1:
             return json.dumps({
                 'articles': data
             })
 
-        if isinstance(data, list) and len(data) is 1:
-            data = data[0]
+        if val and isinstance(val, list) and len(val) is 1:
+            val = val[0]
 
-        if isinstance(data, list) and len(data) < 1:
-            data = {}
+        data.update({"results": val})
 
         errors = data.get('errors', None)
 

diff --git a/authors/apps/articles/serializers.py b/authors/apps/articles/serializers.py
@@ -2,12 +2,15 @@
 Serializer classes for articles
 """
 from rest_framework import serializers
+from rest_framework.pagination import PageNumberPagination
 
 from authors.apps.articles.exceptions import NotFoundException
 from authors.apps.articles.models import Article
 from authors.apps.articles.utils import get_date
 from authors.apps.authentication.models import User
 from authors.apps.authentication.serializers import UserSerializer
+from authors.apps.profiles.models import UserProfile
+from authors.apps.profiles.serializers import RetrieveUserProfileSerializer
 
 
 class ArticleSerializer(serializers.ModelSerializer):
@@ -64,7 +67,9 @@ def to_representation(self, instance):
         :return:
         """
         response = super().to_representation(instance)
-        response['author'] = UserSerializer(instance.author).data
+        profile = RetrieveUserProfileSerializer(UserProfile.objects.get(user=instance.author)).data
+
+        response['author'] = profile
         return response
 
     class Meta:
@@ -75,3 +80,27 @@ class behaviours
         # noinspection SpellCheckingInspection
         fields = ('slug', 'title', 'description', 'body', 'created_at',
                   'updated_at', 'favorited', 'favorites_count', 'photo_url', 'author')
+
+
+class PaginatedArticleSerializer(PageNumberPagination):
+    """
+    Pagination class
+    Inherits from PageNumberPagination
+    Paginates articles
+    """
+    page_size = 4
+
+    def get_paginated_response(self, data):
+        """
+        Formats response to include page links
+        :param data:
+        :return:
+        """
+        return {
+            'links': {
+                'next': self.get_next_link(),
+                'previous': self.get_previous_link()
+            },
+            'count': self.page.paginator.count,
+            'results': data
+        }
diff --git a/authors/apps/articles/tests/test_articles.py b/authors/apps/articles/tests/test_articles.py
@@ -115,7 +115,7 @@ def test_list_specific_article(self):
         self.assertIn('article', response.json())
         self.assertIsInstance(response.json().get("article"), dict)
 
-        slug = response.json().get("article").get("slug")
+        slug = response.json().get("article").get("results").get("slug")
 
         response = self.client.get(
             "/api/articles/{0}/".format(slug), content_type='application/json')
@@ -137,7 +137,7 @@ def test_delete_specific_article(self):
         self.assertIn('article', response.json())
         self.assertIsInstance(response.json().get("article"), dict)
 
-        slug = response.json().get("article").get("slug")
+        slug = response.json().get("article").get("results").get("slug")
 
         response = self.client.delete(
             "/api/articles/{0}/".format(slug), content_type='application/json')
@@ -166,7 +166,7 @@ def test_list_many_articles(self):
         response = self.client.get(
             "/api/articles/", content_type='application/json')
         self.assertEqual(response.status_code, 200)
-        self.assertIsInstance(response.json().get("articles"), list)
+        self.assertIsInstance(response.json().get("articles").get("results"), list)
         self.assertEqual(len(response.json().get("articles")), 3)
 
     def test_update_article(self):
@@ -183,7 +183,7 @@ def test_update_article(self):
         self.assertIn('article', response.json())
         self.assertIsInstance(response.json().get("article"), dict)
 
-        slug = response.json().get("article").get("slug")
+        slug = response.json().get("article").get("results").get("slug")
 
         response = self.client.put(
             "/api/articles/{0}/".format(slug), data=json.dumps(
@@ -206,7 +206,7 @@ def test_update_article_missing_data_and_not_exist(self):
         self.assertIn('article', response.json())
         self.assertIsInstance(response.json().get("article"), dict)
 
-        slug = response.json().get("article").get("slug")
+        slug = response.json().get("article").get("results").get("slug")
 
         response = self.client.put(
             "/api/articles/{0}/".format(slug), data=json.dumps(

diff --git a/authors/apps/articles/views.py b/authors/apps/articles/views.py
@@ -10,7 +10,7 @@
 from authors.apps.articles.exceptions import NotFoundException, InvalidQueryParameterException
 from authors.apps.articles.models import Article
 from authors.apps.articles.renderer import ArticleJSONRenderer
-from authors.apps.articles.serializers import ArticleSerializer
+from authors.apps.articles.serializers import ArticleSerializer, PaginatedArticleSerializer
 
 
 # noinspection PyUnusedLocal,PyMethodMayBeStatic
@@ -51,12 +51,14 @@ def to_int(val):
 
         queryset = Article.objects.all()
         if queryset.count() > 0:
-            queryset = queryset[offset:limit]
+            queryset = queryset[offset:]
 
-        serializer = self.serializer_class(queryset, many=True)
-        data = serializer.data
+        data = self.serializer_class(queryset, many=True).data
 
-        return Response(data)
+        pager_class = PaginatedArticleSerializer()
+        pager_class.page_size = limit
+
+        return Response(pager_class.get_paginated_response(pager_class.paginate_queryset(data, request)))
 
     def retrieve(self, request, slug=None):
         """