Merge pull request #439 from lcary/patch-1

Extend ReadOnlyModelViewSet with prefetch mixins

Author: sliverc

Diff for: AUTHORS

@@ -6,6 +6,7 @@ Greg Aker <[email protected]>
 Jamie Bliss <[email protected]>
 Jerel Unruh <[email protected]>
 Léo S. <[email protected]>
+Luc Cary <[email protected]>
 Matt Layman <https://www.mattlayman.com>
 Ola Tarkowska <[email protected]>
 Oliver Sauder <[email protected]>

Diff for: CHANGELOG.md

@@ -2,6 +2,7 @@ v2.5.0 - [unreleased]
 * Add new pagination classes based on JSON:API query parameter *recommendations*:
   * JsonApiPageNumberPagination and JsonApiLimitOffsetPagination. See [usage docs](docs/usage.md#pagination).
   * Deprecates PageNumberPagination and LimitOffsetPagination.
+* Add ReadOnlyModelViewSet extension with prefetch mixins.
 
 v2.4.0 - Released January 25, 2018
 

Diff for: docs/usage.md

@@ -612,19 +612,29 @@ class QuestSerializer(serializers.ModelSerializer):
 
 #### Performance improvements
 
-Be aware that using included resources without any form of prefetching **WILL HURT PERFORMANCE** as it will introduce m*(n+1) queries.
+Be aware that using included resources without any form of prefetching **WILL HURT PERFORMANCE** as it will introduce m\*(n+1) queries.
 
 A viewset helper was designed to allow for greater flexibility and it is automatically available when subclassing
-`views.ModelViewSet`
-```
- # When MyViewSet is called with ?include=author it will dynamically prefetch author and author.bio
- class MyViewSet(viewsets.ModelViewSet):
+`rest_framework_json_api.views.ModelViewSet`:
+```python
+from rest_framework_json_api import views
+
+# When MyViewSet is called with ?include=author it will dynamically prefetch author and author.bio
+class MyViewSet(views.ModelViewSet):
     queryset = Book.objects.all()
     prefetch_for_includes = {
-    '__all__': [],
-    'author': ['author', 'author__bio']
-    'category.section': ['category']
-}
+        '__all__': [],
+        'author': ['author', 'author__bio'],
+        'category.section': ['category']
+    }
+```
+
+An additional convenience DJA class exists for read-only views, just as it does in DRF.
+```python
+from rest_framework_json_api import views
+
+class MyReadOnlyViewSet(views.ReadOnlyModelViewSet):
+    # ...
 ```
 
 The special keyword `__all__` can be used to specify a prefetch which should be done regardless of the include, similar to making the prefetch yourself on the QuerySet.

Diff for: example/tests/unit/test_renderers.py

@@ -33,14 +33,31 @@ class DummyTestViewSet(views.ModelViewSet):
     serializer_class = DummyTestSerializer
 
 
+class ReadOnlyDummyTestViewSet(views.ReadOnlyModelViewSet):
+    queryset = Entry.objects.all()
+    serializer_class = DummyTestSerializer
+
+
+def render_dummy_test_serialized_view(view_class):
+    serializer = DummyTestSerializer(instance=Entry())
+    renderer = JSONRenderer()
+    return renderer.render(
+        serializer.data,
+        renderer_context={'view': view_class()})
+
+
 def test_simple_reverse_relation_included_renderer():
     '''
     Test renderer when a single reverse fk relation is passed.
     '''
-    serializer = DummyTestSerializer(instance=Entry())
-    renderer = JSONRenderer()
-    rendered = renderer.render(
-        serializer.data,
-        renderer_context={'view': DummyTestViewSet()})
+    rendered = render_dummy_test_serialized_view(
+        DummyTestViewSet)
+
+    assert rendered
+
+
+def test_simple_reverse_relation_included_read_only_viewset():
+    rendered = render_dummy_test_serialized_view(
+        ReadOnlyDummyTestViewSet)
 
     assert rendered

Diff for: rest_framework_json_api/views.py

@@ -38,7 +38,7 @@ class MyViewSet(viewsets.ModelViewSet):
             queryset = Book.objects.all()
             prefetch_for_includes = {
                 '__all__': [],
-                'author': ['author', 'author__authorbio']
+                'author': ['author', 'author__authorbio'],
                 'category.section': ['category']
             }
         """
@@ -102,6 +102,12 @@ class ModelViewSet(AutoPrefetchMixin, PrefetchForIncludesHelperMixin, viewsets.M
     pass
 
 
+class ReadOnlyModelViewSet(AutoPrefetchMixin,
+                           PrefetchForIncludesHelperMixin,
+                           viewsets.ReadOnlyModelViewSet):
+    pass
+
+
 class RelationshipView(generics.GenericAPIView):
     serializer_class = ResourceIdentifierObjectSerializer
     self_link_view_name = None