Support polymorphic nested serializer url fields (#485)

Author: icereval

AUTHORS

@@ -10,6 +10,7 @@ Jonathan Senecal <contact@jonathansenecal.com>
 Léo S. <leo@naeka.fr>
 Luc Cary <luc.cary@gmail.com>
 Matt Layman <https://www.mattlayman.com>
+Michael Haselton <icereval@gmail.com>
 Ola Tarkowska <ola@red-aries.com>
 Oliver Sauder <os@esite.ch>
 Raphael Cohen <raphael.cohen.utt@gmail.com>

CHANGELOG.md

@@ -8,6 +8,20 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 Note that in line with [Django REST Framework policy](http://www.django-rest-framework.org/topics/release-notes/),
 any parts of the framework not mentioned in the documentation should generally be considered private API, and may be subject to change.
 
+
+## [Unreleased]
+
+### Added
+
+### Deprecated
+
+### Changed
+
+### Fixed
+
+* Pass context from `PolymorphicModelSerializer` to child serializers to support fields which require a `request` context such as `url`.
+
+
 ## [2.6.0] - 2018-09-20
 
 ### Added

example/factories.py

@@ -12,6 +12,7 @@
     Comment,
     Company,
     Entry,
+    ProjectType,
     ResearchProject,
     TaggedItem
 )
@@ -89,12 +90,20 @@ class Meta:
     tag = factory.LazyAttribute(lambda x: faker.word())
 
 
+class ProjectTypeFactory(factory.django.DjangoModelFactory):
+    class Meta:
+        model = ProjectType
+
+    name = factory.LazyAttribute(lambda x: faker.name())
+
+
 class ArtProjectFactory(factory.django.DjangoModelFactory):
     class Meta:
         model = ArtProject
 
     topic = factory.LazyAttribute(lambda x: faker.catch_phrase())
     artist = factory.LazyAttribute(lambda x: faker.name())
+    project_type = factory.SubFactory(ProjectTypeFactory)
 
 
 class ResearchProjectFactory(factory.django.DjangoModelFactory):
@@ -103,6 +112,7 @@ class Meta:
 
     topic = factory.LazyAttribute(lambda x: faker.catch_phrase())
     supervisor = factory.LazyAttribute(lambda x: faker.name())
+    project_type = factory.SubFactory(ProjectTypeFactory)
 
 
 class CompanyFactory(factory.django.DjangoModelFactory):

example/migrations/0005_auto_20180922_1508.py

@@ -0,0 +1,43 @@
+# Generated by Django 2.1.1 on 2018-09-22 15:08
+
+from django.db import migrations, models
+import django.db.models.deletion
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('example', '0004_auto_20171011_0631'),
+    ]
+
+    operations = [
+        migrations.CreateModel(
+            name='ProjectType',
+            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='artproject',
+            options={'base_manager_name': 'objects'},
+        ),
+        migrations.AlterModelOptions(
+            name='project',
+            options={'base_manager_name': 'objects'},
+        ),
+        migrations.AlterModelOptions(
+            name='researchproject',
+            options={'base_manager_name': 'objects'},
+        ),
+        migrations.AddField(
+            model_name='project',
+            name='project_type',
+            field=models.ForeignKey(null=True, on_delete=django.db.models.deletion.CASCADE, to='example.ProjectType'),
+        ),
+    ]

example/models.py

@@ -119,8 +119,20 @@ class Meta:
         ordering = ('id',)
 
 
+@python_2_unicode_compatible
+class ProjectType(BaseModel):
+    name = models.CharField(max_length=50)
+
+    def __str__(self):
+        return self.name
+
+    class Meta:
+        ordering = ('id',)
+
+
 class Project(PolymorphicModel):
     topic = models.CharField(max_length=30)
+    project_type = models.ForeignKey(ProjectType, null=True, on_delete=models.CASCADE)
 
 
 class ArtProject(Project):

example/serializers.py

@@ -15,6 +15,7 @@
     Company,
     Entry,
     Project,
+    ProjectType,
     ResearchProject,
     TaggedItem
 )
@@ -218,19 +219,34 @@ class Meta:
         # fields = ('entry', 'body', 'author',)
 
 
-class ArtProjectSerializer(serializers.ModelSerializer):
+class ProjectTypeSerializer(serializers.ModelSerializer):
+    class Meta:
+        model = ProjectType
+        fields = ('name', 'url',)
+
+
+class BaseProjectSerializer(serializers.ModelSerializer):
+    included_serializers = {
+        'project_type': ProjectTypeSerializer,
+    }
+
+
+class ArtProjectSerializer(BaseProjectSerializer):
     class Meta:
         model = ArtProject
         exclude = ('polymorphic_ctype',)
 
 
-class ResearchProjectSerializer(serializers.ModelSerializer):
+class ResearchProjectSerializer(BaseProjectSerializer):
     class Meta:
         model = ResearchProject
         exclude = ('polymorphic_ctype',)
 
 
 class ProjectSerializer(serializers.PolymorphicModelSerializer):
+    included_serializers = {
+        'project_type': ProjectTypeSerializer,
+    }
     polymorphic_serializers = [ArtProjectSerializer, ResearchProjectSerializer]
 
     class Meta:

example/tests/integration/test_polymorphism.py

@@ -3,6 +3,8 @@
 import pytest
 from django.urls import reverse
 
+from example.factories import ArtProjectFactory, ProjectTypeFactory
+
 pytestmark = pytest.mark.django_db
 
 
@@ -57,13 +59,22 @@ def test_polymorphism_on_polymorphic_model_detail_patch(single_art_project, clie
 def test_polymorphism_on_polymorphic_model_list_post(client):
     test_topic = 'New test topic {}'.format(random.randint(0, 999999))
     test_artist = 'test-{}'.format(random.randint(0, 999999))
+    test_project_type = ProjectTypeFactory()
     url = reverse('project-list')
     data = {
         'data': {
             'type': 'artProjects',
             'attributes': {
                 'topic': test_topic,
                 'artist': test_artist
+            },
+            'relationships': {
+                'projectType': {
+                    'data': {
+                        'type': 'projectTypes',
+                        'id': test_project_type.pk
+                    }
+                }
             }
         }
     }
@@ -73,6 +84,22 @@ def test_polymorphism_on_polymorphic_model_list_post(client):
     assert content['data']['type'] == "artProjects"
     assert content['data']['attributes']['topic'] == test_topic
     assert content['data']['attributes']['artist'] == test_artist
+    assert content['data']['relationships']['projectType']['data']['id'] == \
+        str(test_project_type.pk)
+
+
+def test_polymorphism_on_polymorphic_model_w_included_serializers(client):
+    test_project = ArtProjectFactory()
+    query = '?include=projectType'
+    url = reverse('project-list')
+    response = client.get(url + query)
+    content = response.json()
+    assert content['data'][0]['id'] == str(test_project.pk)
+    assert content['data'][0]['type'] == 'artProjects'
+    assert content['data'][0]['relationships']['projectType']['data']['id'] == \
+        str(test_project.project_type.pk)
+    assert content['included'][0]['type'] == 'projectTypes'
+    assert content['included'][0]['id'] == str(test_project.project_type.pk)
 
 
 def test_polymorphic_model_without_any_instance(client):

example/urls.py

@@ -13,6 +13,7 @@
     EntryRelationshipView,
     EntryViewSet,
     NonPaginatedEntryViewSet,
+    ProjectTypeViewset,
     ProjectViewset
 )
 
@@ -25,6 +26,7 @@
 router.register(r'comments', CommentViewSet)
 router.register(r'companies', CompanyViewset)
 router.register(r'projects', ProjectViewset)
+router.register(r'project-types', ProjectTypeViewset)
 
 urlpatterns = [
     url(r'^', include(router.urls)),

example/urls_test.py

@@ -15,6 +15,7 @@
     FiltersetEntryViewSet,
     NoFiltersetEntryViewSet,
     NonPaginatedEntryViewSet,
+    ProjectTypeViewset,
     ProjectViewset
 )
 
@@ -30,6 +31,7 @@
 router.register(r'comments', CommentViewSet)
 router.register(r'companies', CompanyViewset)
 router.register(r'projects', ProjectViewset)
+router.register(r'project-types', ProjectTypeViewset)
 
 # for the old tests
 router.register(r'identities', Identity)

example/views.py

@@ -13,14 +13,15 @@
 from rest_framework_json_api.utils import format_drf_errors
 from rest_framework_json_api.views import ModelViewSet, RelationshipView
 
-from example.models import Author, Blog, Comment, Company, Entry, Project
+from example.models import Author, Blog, Comment, Company, Entry, Project, ProjectType
 from example.serializers import (
     AuthorSerializer,
     BlogSerializer,
     CommentSerializer,
     CompanySerializer,
     EntrySerializer,
-    ProjectSerializer
+    ProjectSerializer,
+    ProjectTypeSerializer
 )
 
 HTTP_422_UNPROCESSABLE_ENTITY = 422
@@ -176,6 +177,11 @@ class ProjectViewset(ModelViewSet):
     serializer_class = ProjectSerializer
 
 
+class ProjectTypeViewset(ModelViewSet):
+    queryset = ProjectType.objects.all()
+    serializer_class = ProjectTypeSerializer
+
+
 class EntryRelationshipView(RelationshipView):
     queryset = Entry.objects.all()
 

rest_framework_json_api/renderers.py

@@ -595,7 +595,9 @@ def render(self, data, accepted_media_type=None, renderer_context=None):
                     if isinstance(serializer.child, rest_framework_json_api.
                                   serializers.PolymorphicModelSerializer):
                         resource_serializer_class = serializer.child.\
-                            get_polymorphic_serializer_for_instance(resource_instance)()
+                            get_polymorphic_serializer_for_instance(resource_instance)(
+                                context=serializer.child.context
+                            )
                     else:
                         resource_serializer_class = serializer.child