Closes #15131: Dynamic queryset annotations for REST API endpoints (#15152)

* Introduce RelatedObjectCountField

* Introduce get_annotations_for_serializer() and enable dynamic annotations

* Add RelatedObjectCountFields to serializers; remove static annotations from querysets

* Remove annotations cleanup logic from BriefModeMixin

* Annotate type for RelatedObjectCountField

* Remove redundant field on TagSerializer

* Add missing reverse relationship for power feeds to rack

* Refactor RelatedObjectCountField to take a single relationship name

netbox/circuits/api/nested_serializers.py

@@ -1,8 +1,8 @@
-from drf_spectacular.utils import extend_schema_field, extend_schema_serializer
-from drf_spectacular.types import OpenApiTypes
+from drf_spectacular.utils import extend_schema_serializer
 from rest_framework import serializers
 
 from circuits.models import *
+from netbox.api.fields import RelatedObjectCountField
 from netbox.api.serializers import WritableNestedSerializer
 
 __all__ = [
@@ -36,7 +36,7 @@ class NestedProviderNetworkSerializer(WritableNestedSerializer):
 )
 class NestedProviderSerializer(WritableNestedSerializer):
     url = serializers.HyperlinkedIdentityField(view_name='circuits-api:provider-detail')
-    circuit_count = serializers.IntegerField(read_only=True)
+    circuit_count = RelatedObjectCountField('circuits')
 
     class Meta:
         model = Provider
@@ -64,7 +64,7 @@ class NestedProviderAccountSerializer(WritableNestedSerializer):
 )
 class NestedCircuitTypeSerializer(WritableNestedSerializer):
     url = serializers.HyperlinkedIdentityField(view_name='circuits-api:circuittype-detail')
-    circuit_count = serializers.IntegerField(read_only=True)
+    circuit_count = RelatedObjectCountField('circuits')
 
     class Meta:
         model = CircuitType

netbox/circuits/api/serializers.py

@@ -6,7 +6,7 @@ from dcim.api.nested_serializers import NestedSiteSerializer
 from dcim.api.serializers import CabledObjectSerializer
 from ipam.models import ASN
 from ipam.api.nested_serializers import NestedASNSerializer
-from netbox.api.fields import ChoiceField, SerializedPKRelatedField
+from netbox.api.fields import ChoiceField, RelatedObjectCountField, SerializedPKRelatedField
 from netbox.api.serializers import NetBoxModelSerializer, WritableNestedSerializer
 from tenancy.api.nested_serializers import NestedTenantSerializer
 from .nested_serializers import *
@@ -32,7 +32,7 @@ class ProviderSerializer(NetBoxModelSerializer):
     )
 
     # Related object counts
-    circuit_count = serializers.IntegerField(read_only=True)
+    circuit_count = RelatedObjectCountField('circuits')
 
     class Meta:
         model = Provider
@@ -80,13 +80,15 @@ class ProviderNetworkSerializer(NetBoxModelSerializer):
 
 class CircuitTypeSerializer(NetBoxModelSerializer):
     url = serializers.HyperlinkedIdentityField(view_name='circuits-api:circuittype-detail')
-    circuit_count = serializers.IntegerField(read_only=True)
+
+    # Related object counts
+    circuit_count = RelatedObjectCountField('circuits')
 
     class Meta:
         model = CircuitType
         fields = [
-            'id', 'url', 'display', 'name', 'slug', 'color', 'description', 'tags', 'custom_fields', 'created', 'last_updated',
-            'circuit_count',
+            'id', 'url', 'display', 'name', 'slug', 'color', 'description', 'tags', 'custom_fields', 'created',
+            'last_updated', 'circuit_count',
         ]
 
 

netbox/circuits/api/views.py

@@ -4,7 +4,6 @@ from circuits import filtersets
 from circuits.models import *
 from dcim.api.views import PassThroughPortMixin
 from netbox.api.viewsets import NetBoxModelViewSet
-from utilities.utils import count_related
 from . import serializers
 
 
@@ -21,9 +20,7 @@ class CircuitsRootView(APIRootView):
 #
 
 class ProviderViewSet(NetBoxModelViewSet):
-    queryset = Provider.objects.annotate(
-        circuit_count=count_related(Circuit, 'provider')
-    )
+    queryset = Provider.objects.all()
     serializer_class = serializers.ProviderSerializer
     filterset_class = filtersets.ProviderFilterSet
 
@@ -33,9 +30,7 @@ class ProviderViewSet(NetBoxModelViewSet):
 #
 
 class CircuitTypeViewSet(NetBoxModelViewSet):
-    queryset = CircuitType.objects.annotate(
-        circuit_count=count_related(Circuit, 'type')
-    )
+    queryset = CircuitType.objects.all()
     serializer_class = serializers.CircuitTypeSerializer
     filterset_class = filtersets.CircuitTypeFilterSet