Add support for GenericRelations (#319)

* Change fake-factory (deprecated) requirement to Faker

* Added support for GenericRelation

* Added GenericRelation example. Fix tests

* Added GenericRelations tests

* Added support for GenericRelations on django 1.8

* implement requested changes

Author: santiavenda2

example/factories/__init__.py

@@ -2,7 +2,7 @@
 
 import factory
 from faker import Factory as FakerFactory
-from example.models import Blog, Author, AuthorBio, Entry, Comment
+from example.models import Blog, Author, AuthorBio, Entry, Comment, TaggedItem
 
 faker = FakerFactory.create()
 faker.seed(983843)
@@ -58,3 +58,11 @@ class Meta:
     body = factory.LazyAttribute(lambda x: faker.text())
     author = factory.SubFactory(AuthorFactory)
 
+
+class TaggedItemFactory(factory.django.DjangoModelFactory):
+
+    class Meta:
+        model = TaggedItem
+
+    content_object = factory.SubFactory(EntryFactory)
+    tag = factory.LazyAttribute(lambda x: faker.word())

example/migrations/0002_taggeditem.py

@@ -0,0 +1,31 @@
+# -*- coding: utf-8 -*-
+# Generated by Django 1.10.5 on 2017-02-01 08:34
+from __future__ import unicode_literals
+
+from django.db import migrations, models
+import django.db.models.deletion
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('contenttypes', '0002_remove_content_type_name'),
+        ('example', '0001_initial'),
+    ]
+
+    operations = [
+        migrations.CreateModel(
+            name='TaggedItem',
+            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)),
+                ('tag', models.SlugField()),
+                ('object_id', models.PositiveIntegerField()),
+                ('content_type', models.ForeignKey(on_delete=django.db.models.deletion.CASCADE, to='contenttypes.ContentType')),
+            ],
+            options={
+                'abstract': False,
+            },
+        ),
+    ]

example/models.py

@@ -1,6 +1,9 @@
 # -*- encoding: utf-8 -*-
 from __future__ import unicode_literals
 
+from django.contrib.contenttypes.models import ContentType
+from django.contrib.contenttypes.fields import GenericForeignKey
+from django.contrib.contenttypes.fields import GenericRelation
 from django.db import models
 from django.utils.encoding import python_2_unicode_compatible
 
@@ -16,10 +19,21 @@ class Meta:
         abstract = True
 
 
+class TaggedItem(BaseModel):
+    tag = models.SlugField()
+    content_type = models.ForeignKey(ContentType, on_delete=models.CASCADE)
+    object_id = models.PositiveIntegerField()
+    content_object = GenericForeignKey('content_type', 'object_id')
+
+    def __str__(self):
+        return self.tag
+
+
 @python_2_unicode_compatible
 class Blog(BaseModel):
     name = models.CharField(max_length=100)
     tagline = models.TextField()
+    tags = GenericRelation(TaggedItem)
 
     def __str__(self):
         return self.name
@@ -54,6 +68,7 @@ class Entry(BaseModel):
     n_comments = models.IntegerField(default=0)
     n_pingbacks = models.IntegerField(default=0)
     rating = models.IntegerField(default=0)
+    tags = GenericRelation(TaggedItem)
 
     def __str__(self):
         return self.headline

example/serializers.py

@@ -1,11 +1,23 @@
 from datetime import datetime
 from rest_framework_json_api import serializers, relations
-from example.models import Blog, Entry, Author, AuthorBio, Comment
+from example.models import Blog, Entry, Author, AuthorBio, Comment, TaggedItem
+
+
+class TaggedItemSerializer(serializers.ModelSerializer):
+
+    class Meta:
+        model = TaggedItem
+        fields = ('tag', )
 
 
 class BlogSerializer(serializers.ModelSerializer):
 
     copyright = serializers.SerializerMethodField()
+    tags = TaggedItemSerializer(many=True, read_only=True)
+
+    include_serializers = {
+        'tags': 'example.serializers.TaggedItemSerializer',
+    }
 
     def get_copyright(self, resource):
         return datetime.now().year
@@ -17,7 +29,8 @@ def get_root_meta(self, resource, many):
 
     class Meta:
         model = Blog
-        fields = ('name', 'url',)
+        fields = ('name', 'url', 'tags')
+        read_only_fields = ('tags', )
         meta_fields = ('copyright',)
 
 
@@ -36,6 +49,7 @@ def __init__(self, *args, **kwargs):
         'comments': 'example.serializers.CommentSerializer',
         'featured': 'example.serializers.EntrySerializer',
         'suggested': 'example.serializers.EntrySerializer',
+        'tags': 'example.serializers.TaggedItemSerializer',
     }
 
     body_format = serializers.SerializerMethodField()
@@ -52,6 +66,7 @@ def __init__(self, *args, **kwargs):
     # single related from serializer
     featured = relations.SerializerMethodResourceRelatedField(
             source='get_featured', model=Entry, read_only=True)
+    tags = TaggedItemSerializer(many=True, read_only=True)
 
     def get_suggested(self, obj):
         return Entry.objects.exclude(pk=obj.pk)
@@ -65,7 +80,8 @@ def get_body_format(self, obj):
     class Meta:
         model = Entry
         fields = ('blog', 'headline', 'body_text', 'pub_date', 'mod_date',
-                  'authors', 'comments', 'featured', 'suggested',)
+                  'authors', 'comments', 'featured', 'suggested', 'tags')
+        read_only_fields = ('tags', )
         meta_fields = ('body_format',)
 
     class JSONAPIMeta:

example/tests/conftest.py

@@ -1,20 +1,23 @@
 import pytest
 from pytest_factoryboy import register
 
-from example.factories import BlogFactory, AuthorFactory, AuthorBioFactory, EntryFactory, CommentFactory
+from example.factories import BlogFactory, AuthorFactory, AuthorBioFactory, EntryFactory, CommentFactory, \
+    TaggedItemFactory
 
 register(BlogFactory)
 register(AuthorFactory)
 register(AuthorBioFactory)
 register(EntryFactory)
 register(CommentFactory)
+register(TaggedItemFactory)
 
 
 @pytest.fixture
-def single_entry(blog, author, entry_factory, comment_factory):
+def single_entry(blog, author, entry_factory, comment_factory, tagged_item_factory):
 
     entry = entry_factory(blog=blog, authors=(author,))
     comment_factory(entry=entry)
+    tagged_item_factory(content_object=entry)
     return entry
 
 

example/tests/integration/test_meta.py

@@ -19,6 +19,11 @@ def test_top_level_meta_for_list_view(blog, client):
             "links": {
                 "self": 'http://testserver/blogs/1'
             },
+            "relationships": {
+                "tags": {
+                    "data": []
+                }
+            },
             "meta": {
                 "copyright": datetime.now().year
             },
@@ -50,6 +55,11 @@ def test_top_level_meta_for_detail_view(blog, client):
             "attributes": {
                 "name": blog.name
             },
+            "relationships": {
+                "tags": {
+                    "data": []
+                }
+            },
             "links": {
                 "self": "http://testserver/blogs/1"
             },

example/tests/integration/test_non_paginated_responses.py

@@ -57,6 +57,9 @@ def test_multiple_entries_no_pagination(multiple_entries, rf):
                             "related": "http://testserver/entries/1/suggested/",
                             "self": "http://testserver/entries/1/relationships/suggested"
                         }
+                    },
+                    "tags": {
+                        "data": []
                     }
                 }
             },
@@ -92,6 +95,9 @@ def test_multiple_entries_no_pagination(multiple_entries, rf):
                             "related": "http://testserver/entries/2/suggested/",
                             "self": "http://testserver/entries/2/relationships/suggested"
                         }
+                    },
+                    "tags": {
+                        "data": []
                     }
                 }
             },

example/tests/integration/test_pagination.py

@@ -50,6 +50,14 @@ def test_pagination_with_single_entry(single_entry, client):
                             "related": "http://testserver/entries/1/suggested/",
                             "self": "http://testserver/entries/1/relationships/suggested"
                         }
+                    },
+                    "tags": {
+                        "data": [
+                            {
+                                "id": "1",
+                                "type": "taggedItems"
+                            }
+                        ]
                     }
                 }
             }],

requirements-development.txt

@@ -2,7 +2,7 @@
 pytest>=2.9.0,<3.0
 pytest-django
 pytest-factoryboy
-fake-factory
+Faker
 recommonmark
 Sphinx
 sphinx_rtd_theme

rest_framework_json_api/utils.py

@@ -30,10 +30,12 @@
 if django.VERSION >= (1, 9):
     from django.db.models.fields.related_descriptors import ManyToManyDescriptor, ReverseManyToOneDescriptor
     ReverseManyRelatedObjectsDescriptor = type(None)
+    from django.contrib.contenttypes.fields import ReverseGenericManyToOneDescriptor
 else:
     from django.db.models.fields.related import ManyRelatedObjectsDescriptor as ManyToManyDescriptor
     from django.db.models.fields.related import ForeignRelatedObjectsDescriptor as ReverseManyToOneDescriptor
     from django.db.models.fields.related import ReverseManyRelatedObjectsDescriptor
+    from django.contrib.contenttypes.fields import ReverseGenericRelatedObjectsDescriptor as ReverseGenericManyToOneDescriptor
 
 
 def get_resource_name(context):
@@ -210,17 +212,23 @@ def get_related_resource_type(relation):
             else:
                 parent_model_relation = getattr(parent_model, parent_serializer.field_name)
 
-            if type(parent_model_relation) is ReverseManyToOneDescriptor:
+            parent_model_relation_type = type(parent_model_relation)
+            if parent_model_relation_type is ReverseManyToOneDescriptor:
                 if django.VERSION >= (1, 9):
                     relation_model = parent_model_relation.rel.related_model
                 elif django.VERSION >= (1, 8):
                     relation_model = parent_model_relation.related.related_model
                 else:
                     relation_model = parent_model_relation.related.model
-            elif type(parent_model_relation) is ManyToManyDescriptor:
+            elif parent_model_relation_type is ManyToManyDescriptor:
                 relation_model = parent_model_relation.field.remote_field.model
-            elif type(parent_model_relation) is ReverseManyRelatedObjectsDescriptor:
+            elif parent_model_relation_type is ReverseManyRelatedObjectsDescriptor:
                 relation_model = parent_model_relation.field.related.model
+            elif parent_model_relation_type is ReverseGenericManyToOneDescriptor:
+                if django.VERSION >= (1, 9):
+                    relation_model = parent_model_relation.rel.model
+                else:
+                    relation_model = parent_model_relation.field.related_model
             else:
                 return get_related_resource_type(parent_model_relation)