Optimizations for PartList API endpoint:

- Remove custom list() function
- Queryset prefetch now performed by the model manager

InvenTree/part/api.py

@@ -536,75 +536,15 @@ class PartList(generics.ListCreateAPIView):
 
         kwargs['starred_parts'] = self.starred_parts
 
+        try:
+            params = self.request.query_params
+
+            kwargs['category_detail'] = str2bool(params.get('category_detail', False))
+        except AttributeError:
+            pass
+
         return self.serializer_class(*args, **kwargs)
 
-    def list(self, request, *args, **kwargs):
-        """
-        Overide the 'list' method, as the PartCategory objects are
-        very expensive to serialize!
-
-        So we will serialize them first, and keep them in memory,
-        so that they do not have to be serialized multiple times...
-        """
-
-        queryset = self.filter_queryset(self.get_queryset())
-
-        page = self.paginate_queryset(queryset)
-
-        if page is not None:
-            serializer = self.get_serializer(page, many=True)
-        else:
-            serializer = self.get_serializer(queryset, many=True)
-
-        data = serializer.data
-
-        # Do we wish to include PartCategory detail?
-        if str2bool(request.query_params.get('category_detail', False)):
-
-            # Work out which part categories we need to query
-            category_ids = set()
-
-            for part in data:
-                cat_id = part['category']
-
-                if cat_id is not None:
-                    category_ids.add(cat_id)
-
-            # Fetch only the required PartCategory objects from the database
-            categories = PartCategory.objects.filter(pk__in=category_ids).prefetch_related(
-                'parts',
-                'parent',
-                'children',
-            )
-
-            category_map = {}
-
-            # Serialize each PartCategory object
-            for category in categories:
-                category_map[category.pk] = part_serializers.CategorySerializer(category).data
-
-            for part in data:
-                cat_id = part['category']
-
-                if cat_id is not None and cat_id in category_map.keys():
-                    detail = category_map[cat_id]
-                else:
-                    detail = None
-
-                part['category_detail'] = detail
-
-        """
-        Determine the response type based on the request.
-        a) For HTTP requests (e.g. via the browseable API) return a DRF response
-        b) For AJAX requests, simply return a JSON rendered response.
-        """
-        if page is not None:
-            return self.get_paginated_response(data)
-        elif request.is_ajax():
-            return JsonResponse(data, safe=False)
-        else:
-            return Response(data)
-
     def perform_create(self, serializer):
         """
         We wish to save the user who created this part!
@@ -619,8 +559,6 @@ class PartList(generics.ListCreateAPIView):
     def get_queryset(self, *args, **kwargs):
 
         queryset = super().get_queryset(*args, **kwargs)
-
-        queryset = part_serializers.PartSerializer.prefetch_queryset(queryset)
         queryset = part_serializers.PartSerializer.annotate_queryset(queryset)
 
         return queryset