Allow type field on none polymorphic serializers

Author: Oliver Sauder

example/factories.py

@@ -7,6 +7,7 @@
     ArtProject,
     Author,
     AuthorBio,
+    AuthorType,
     Blog,
     Comment,
     Company,
@@ -26,6 +27,13 @@ class Meta:
     name = factory.LazyAttribute(lambda x: faker.name())
 
 
+class AuthorTypeFactory(factory.django.DjangoModelFactory):
+    class Meta:
+        model = AuthorType
+
+    name = factory.LazyAttribute(lambda x: faker.name())
+
+
 class AuthorFactory(factory.django.DjangoModelFactory):
     class Meta:
         model = Author
@@ -34,6 +42,7 @@ class Meta:
     email = factory.LazyAttribute(lambda x: faker.email())
 
     bio = factory.RelatedFactory('example.factories.AuthorBioFactory', 'author')
+    type = factory.SubFactory(AuthorTypeFactory)
 
 
 class AuthorBioFactory(factory.django.DjangoModelFactory):

example/migrations/0004_auto_20171011_0631.py

@@ -0,0 +1,62 @@
+# -*- coding: utf-8 -*-
+# Generated by Django 1.11.6 on 2017-10-11 06:31
+from __future__ import unicode_literals
+
+from django.db import migrations, models
+import django.db.models.deletion
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('example', '0003_polymorphics'),
+    ]
+
+    operations = [
+        migrations.CreateModel(
+            name='AuthorType',
+            fields=[
+                ('id', models.AutoField(auto_created=True, primary_key=True, serialize=False, verbose_name='ID')),
+                ('created_at', models.DateTimeField(auto_now_add=True)),
+                ('modified_at', models.DateTimeField(auto_now=True)),
+                ('name', models.CharField(max_length=50)),
+            ],
+            options={
+                'ordering': ('id',),
+            },
+        ),
+        migrations.AlterModelOptions(
+            name='author',
+            options={'ordering': ('id',)},
+        ),
+        migrations.AlterModelOptions(
+            name='authorbio',
+            options={'ordering': ('id',)},
+        ),
+        migrations.AlterModelOptions(
+            name='blog',
+            options={'ordering': ('id',)},
+        ),
+        migrations.AlterModelOptions(
+            name='comment',
+            options={'ordering': ('id',)},
+        ),
+        migrations.AlterModelOptions(
+            name='entry',
+            options={'ordering': ('id',)},
+        ),
+        migrations.AlterModelOptions(
+            name='taggeditem',
+            options={'ordering': ('id',)},
+        ),
+        migrations.AlterField(
+            model_name='entry',
+            name='authors',
+            field=models.ManyToManyField(related_name='entries', to='example.Author'),
+        ),
+        migrations.AddField(
+            model_name='author',
+            name='type',
+            field=models.ForeignKey(null=True, on_delete=django.db.models.deletion.CASCADE, to='example.AuthorType'),
+        ),
+    ]

example/models.py

@@ -45,10 +45,22 @@ class Meta:
         ordering = ('id',)
 
 
+@python_2_unicode_compatible
+class AuthorType(BaseModel):
+    name = models.CharField(max_length=50)
+
+    def __str__(self):
+        return self.name
+
+    class Meta:
+        ordering = ('id',)
+
+
 @python_2_unicode_compatible
 class Author(BaseModel):
     name = models.CharField(max_length=50)
     email = models.EmailField()
+    type = models.ForeignKey(AuthorType, null=True)
 
     def __str__(self):
         return self.name

example/serializers.py

@@ -9,6 +9,7 @@
     ArtProject,
     Author,
     AuthorBio,
+    AuthorType,
     Blog,
     Comment,
     Company,
@@ -101,6 +102,12 @@ class JSONAPIMeta:
         included_resources = ['comments']
 
 
+class AuthorTypeSerializer(serializers.ModelSerializer):
+    class Meta:
+        model = AuthorType
+        fields = ('name', )
+
+
 class AuthorBioSerializer(serializers.ModelSerializer):
     class Meta:
         model = AuthorBio
@@ -109,12 +116,13 @@ class Meta:
 
 class AuthorSerializer(serializers.ModelSerializer):
     included_serializers = {
-        'bio': AuthorBioSerializer
+        'bio': AuthorBioSerializer,
+        'type': AuthorTypeSerializer
     }
 
     class Meta:
         model = Author
-        fields = ('name', 'email', 'bio', 'entries')
+        fields = ('name', 'email', 'bio', 'entries', 'type')
 
 
 class WriterSerializer(serializers.ModelSerializer):

example/tests/conftest.py

@@ -5,6 +5,7 @@
     ArtProjectFactory,
     AuthorBioFactory,
     AuthorFactory,
+    AuthorTypeFactory,
     BlogFactory,
     CommentFactory,
     CompanyFactory,
@@ -16,6 +17,7 @@
 register(BlogFactory)
 register(AuthorFactory)
 register(AuthorBioFactory)
+register(AuthorTypeFactory)
 register(EntryFactory)
 register(CommentFactory)
 register(TaggedItemFactory)

example/tests/test_model_viewsets.py

@@ -1,3 +1,4 @@
+import pytest
 from django.conf import settings
 from django.contrib.auth import get_user_model
 from django.core.urlresolvers import reverse
@@ -226,3 +227,31 @@ def test_key_in_post(self):
         self.assertEqual(
             get_user_model().objects.get(pk=self.miles.pk).email,
             'miles@trumpet.org')
+
+
+@pytest.mark.django_db
+def test_patch_allow_field_type(author, author_type_factory, client):
+    """
+    Verify that type field may be updated.
+    """
+    author_type = author_type_factory()
+    url = reverse('author-detail', args=[author.id])
+
+    data = {
+        'data': {
+            'id': author.id,
+            'type': 'authors',
+            'relationships': {
+                'data': {
+                    'id': author_type.id,
+                    'type': 'author-type'
+                }
+            }
+        }
+    }
+
+    response = client.patch(url,
+                            content_type='application/vnd.api+json',
+                            data=dump_json(data))
+
+    assert response.status_code == 200

example/tests/test_performance.py

@@ -50,8 +50,9 @@ def test_query_count_include_author(self):
         1. Primary resource COUNT query
         2. Primary resource SELECT
         3. Authors prefetched
-        3. Entries prefetched
+        4. Author types prefetched
+        5. Entries prefetched
         """
-        with self.assertNumQueries(4):
+        with self.assertNumQueries(5):
             response = self.client.get('/comments?include=author&page_size=25')
             self.assertEqual(len(response.data['results']), 25)

example/views.py

@@ -78,7 +78,7 @@ class CommentViewSet(ModelViewSet):
     serializer_class = CommentSerializer
     prefetch_for_includes = {
         '__all__': [],
-        'author': ['author', 'author__bio', 'author__entries'],
+        'author': ['author', 'author__bio', 'author__entries', 'author__type'],
         'entry': ['author', 'author__bio', 'author__entries']
     }
 

rest_framework_json_api/parsers.py

@@ -6,7 +6,7 @@
 from rest_framework import parsers
 from rest_framework.exceptions import ParseError
 
-from . import exceptions, renderers, utils
+from . import exceptions, renderers, serializers, utils
 
 
 class JSONParser(parsers.JSONParser):
@@ -83,9 +83,10 @@ def parse(self, stream, media_type=None, parser_context=None):
             raise ParseError('Received document does not contain primary data')
 
         data = result.get('data')
+        view = parser_context['view']
 
         from rest_framework_json_api.views import RelationshipView
-        if isinstance(parser_context['view'], RelationshipView):
+        if isinstance(view, RelationshipView):
             # We skip parsing the object as JSONAPI Resource Identifier Object and not a regular
             # Resource Object
             if isinstance(data, list):
@@ -129,8 +130,12 @@ def parse(self, stream, media_type=None, parser_context=None):
             raise ParseError("The resource identifier object must contain an 'id' member")
 
         # Construct the return data
+        serializer_class = getattr(view, 'serializer_class', None)
         parsed_data = {'id': data.get('id')} if 'id' in data else {}
-        parsed_data['type'] = data.get('type')
+        # `type` field needs to be allowed in none polymorphic serializers
+        if serializer_class is not None:
+            if issubclass(serializer_class, serializers.PolymorphicModelSerializer):
+                parsed_data['type'] = data.get('type')
         parsed_data.update(self.parse_attributes(data))
         parsed_data.update(self.parse_relationships(data))
         parsed_data.update(self.parse_metadata(result))