Merge pull request #24 from MaxDude132/23-make-the-prefetching-work-for-all-parent-containers-not-just-listserializer

23 - Fix prefetching issue when using DictField

Author: MaxDude132

serializer_prefetch/base.py

@@ -216,7 +216,11 @@ def _get_fields(self, serializer: serializers.Field):
             if field.write_only:
                 continue
 
-            if not isinstance(field, serializers.BaseSerializer):
+            child = getattr(field, "child", None)
+
+            if not isinstance(field, serializers.BaseSerializer) and not isinstance(
+                child, serializers.BaseSerializer
+            ):
                 continue
 
             yield field
@@ -233,9 +237,7 @@ def _get_serializer_field_relations(
         force_prefetch = self.get_force_prefetch_data(serializer)
 
         for field in self._get_fields(serializer):
-            future_should_prefetch = should_prefetch or isinstance(
-                field, serializers.ListSerializer
-            )
+            future_should_prefetch = should_prefetch or hasattr(field, "child")
 
             source = getattr(field, "_prefetch_source", None) or field.source
 
@@ -283,7 +285,7 @@ def _get_serializer_field_relations(
 
             meta = (
                 getattr(field.child, "Meta", None)
-                if isinstance(field, serializers.ListSerializer)
+                if hasattr(field, "child")
                 else getattr(field, "Meta", None)
             )
             if meta:

setup.py

@@ -4,7 +4,7 @@
 # drf-serializer-prefetch
 from setuptools import find_packages, setup
 
-VERSION = "1.1.7"
+VERSION = "1.1.8"
 DESCRIPTION = "An automatic prefetcher for django-rest-framework."
 this_directory = Path(__file__).parent
 LONG_DESCRIPTION = (this_directory / "README.md").read_text()

tests/test_serializers.py

@@ -923,3 +923,24 @@ class Meta:
             data,
             [{"label": "Margherita", "extra_data": {"label": "Margherita"}}],
         )
+
+    def test_dict_serializer(self):
+        class ToppingDictSerializer(serializers.DictField):
+            child = ToppingSerializer()
+
+            def to_representation(self, value):
+                value = {obj.label: ToppingSerializer(obj).data for obj in value.all()}
+                return super().to_representation(value)
+
+        class PizzaSerializer(PrefetchingSerializerMixin, serializers.ModelSerializer):
+            toppings = ToppingDictSerializer()
+
+            class Meta:
+                model = Pizza
+                fields = ("label", "toppings")
+
+        pizzas = Pizza.objects.all()
+        serializer = PizzaSerializer(pizzas, many=True)
+
+        with self.assertNumQueries(2):
+            serializer.data