Remove AutoPrefetchMixin

Author: jarekwg

CHANGELOG.md

@@ -13,6 +13,7 @@ any parts of the framework not mentioned in the documentation should generally b
 ### Changed
 
 * Moved resolving of `included_serialzers` and `related_serializers` classes to serializer's meta class.
+* Removed `PreloadIncludesMixin`, as the logic did not work when nesting includes, and the laborious effort needed in its manual config was unnecessary.
 
 ### Deprecated
 

example/tests/unit/test_filter_schema_params.py

@@ -20,8 +20,6 @@ class DummyEntryViewSet(EntryViewSet):
     }
 
     def __init__(self, **kwargs):
-        # dummy up self.request since PreloadIncludesMixin expects it to be defined
-        self.request = None
         super(DummyEntryViewSet, self).__init__(**kwargs)
 
 

rest_framework_json_api/views.py

@@ -11,6 +11,7 @@
 from django.db.models.manager import Manager
 from django.db.models.query import QuerySet
 from django.urls import NoReverseMatch
+from django.utils.module_loading import import_string as import_class_from_dotted_path
 from rest_framework import generics, viewsets
 from rest_framework.exceptions import MethodNotAllowed, NotFound
 from rest_framework.fields import get_attribute
@@ -30,54 +31,6 @@
 )
 
 
-class PreloadIncludesMixin(object):
-    """
-    This mixin provides a helper attributes to select or prefetch related models
-    based on the include specified in the URL.
-
-    __all__ can be used to specify a prefetch which should be done regardless of the include
-
-
-    .. code:: python
-
-        # When MyViewSet is called with ?include=author it will prefetch author and authorbio
-        class MyViewSet(viewsets.ModelViewSet):
-            queryset = Book.objects.all()
-            prefetch_for_includes = {
-                '__all__': [],
-                'category.section': ['category']
-            }
-            select_for_includes = {
-                '__all__': [],
-                'author': ['author', 'author__authorbio'],
-            }
-    """
-
-    def get_select_related(self, include):
-        return getattr(self, "select_for_includes", {}).get(include, None)
-
-    def get_prefetch_related(self, include):
-        return getattr(self, "prefetch_for_includes", {}).get(include, None)
-
-    def get_queryset(self, *args, **kwargs):
-        qs = super(PreloadIncludesMixin, self).get_queryset(*args, **kwargs)
-
-        included_resources = get_included_resources(
-            self.request, self.get_serializer_class()
-        )
-        for included in included_resources + ["__all__"]:
-
-            select_related = self.get_select_related(included)
-            if select_related is not None:
-                qs = qs.select_related(*select_related)
-
-            prefetch_related = self.get_prefetch_related(included)
-            if prefetch_related is not None:
-                qs = qs.prefetch_related(*prefetch_related)
-
-        return qs
-
-
 class AutoPrefetchMixin(object):
     def get_queryset(self, *args, **kwargs):
         """This mixin adds automatic prefetching for OneToOne and ManyToMany fields."""
@@ -182,6 +135,8 @@ def get_related_serializer_class(self):
                     False
                 ), 'Either "included_serializers" or "related_serializers" should be configured'
 
+            if not isinstance(_class, type):
+                return import_class_from_dotted_path(_class)
             return _class
 
         return parent_serializer_class
@@ -215,13 +170,13 @@ def get_related_instance(self):
 
 
 class ModelViewSet(
-    AutoPrefetchMixin, PreloadIncludesMixin, RelatedMixin, viewsets.ModelViewSet
+    AutoPrefetchMixin, RelatedMixin, viewsets.ModelViewSet
 ):
     http_method_names = ["get", "post", "patch", "delete", "head", "options"]
 
 
 class ReadOnlyModelViewSet(
-    AutoPrefetchMixin, PreloadIncludesMixin, RelatedMixin, viewsets.ReadOnlyModelViewSet
+    AutoPrefetchMixin, RelatedMixin, viewsets.ReadOnlyModelViewSet
 ):
     http_method_names = ["get", "post", "patch", "delete", "head", "options"]