Refactor RelatedObjectCountField to take a single relationship name

netbox/circuits/api/nested_serializers.py

@@ -36,7 +36,7 @@ class NestedProviderNetworkSerializer(WritableNestedSerializer):
 )
 class NestedProviderSerializer(WritableNestedSerializer):
     url = serializers.HyperlinkedIdentityField(view_name='circuits-api:provider-detail')
-    circuit_count = RelatedObjectCountField('circuits.circuit', 'provider')
+    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 = RelatedObjectCountField('circuits.circuit', 'type')
+    circuit_count = RelatedObjectCountField('circuits')
 
     class Meta:
         model = CircuitType

netbox/circuits/api/serializers.py

@@ -32,7 +32,7 @@ class ProviderSerializer(NetBoxModelSerializer):
     )
 
     # Related object counts
-    circuit_count = RelatedObjectCountField('circuits.circuit', 'provider')
+    circuit_count = RelatedObjectCountField('circuits')
 
     class Meta:
         model = Provider
@@ -82,7 +82,7 @@ class CircuitTypeSerializer(NetBoxModelSerializer):
     url = serializers.HyperlinkedIdentityField(view_name='circuits-api:circuittype-detail')
 
     # Related object counts
-    circuit_count = RelatedObjectCountField('circuits.circuit', 'type')
+    circuit_count = RelatedObjectCountField('circuits')
 
     class Meta:
         model = CircuitType

netbox/core/api/serializers.py

@@ -28,7 +28,7 @@ class DataSourceSerializer(NetBoxModelSerializer):
     )
 
     # Related object counts
-    file_count = RelatedObjectCountField('core.datafile', 'source')
+    file_count = RelatedObjectCountField('datafiles')
 
     class Meta:
         model = DataSource

netbox/dcim/api/nested_serializers.py

@@ -111,7 +111,7 @@ class NestedLocationSerializer(WritableNestedSerializer):
 )
 class NestedRackRoleSerializer(WritableNestedSerializer):
     url = serializers.HyperlinkedIdentityField(view_name='dcim-api:rackrole-detail')
-    rack_count = RelatedObjectCountField('dcim.rack', 'role')
+    rack_count = RelatedObjectCountField('racks')
 
     class Meta:
         model = models.RackRole
@@ -123,7 +123,7 @@ class NestedRackRoleSerializer(WritableNestedSerializer):
 )
 class NestedRackSerializer(WritableNestedSerializer):
     url = serializers.HyperlinkedIdentityField(view_name='dcim-api:rack-detail')
-    device_count = RelatedObjectCountField('dcim.device', 'rack')
+    device_count = RelatedObjectCountField('devices')
 
     class Meta:
         model = models.Rack
@@ -151,7 +151,7 @@ class NestedRackReservationSerializer(WritableNestedSerializer):
 )
 class NestedManufacturerSerializer(WritableNestedSerializer):
     url = serializers.HyperlinkedIdentityField(view_name='dcim-api:manufacturer-detail')
-    devicetype_count = RelatedObjectCountField('dcim.devicetype', 'manufacturer')
+    devicetype_count = RelatedObjectCountField('device_types')
 
     class Meta:
         model = models.Manufacturer
@@ -164,7 +164,7 @@ class NestedManufacturerSerializer(WritableNestedSerializer):
 class NestedDeviceTypeSerializer(WritableNestedSerializer):
     url = serializers.HyperlinkedIdentityField(view_name='dcim-api:devicetype-detail')
     manufacturer = NestedManufacturerSerializer(read_only=True)
-    device_count = RelatedObjectCountField('dcim.device', 'device_type')
+    device_count = RelatedObjectCountField('instances')
 
     class Meta:
         model = models.DeviceType
@@ -274,8 +274,8 @@ class NestedInventoryItemTemplateSerializer(WritableNestedSerializer):
 )
 class NestedDeviceRoleSerializer(WritableNestedSerializer):
     url = serializers.HyperlinkedIdentityField(view_name='dcim-api:devicerole-detail')
-    device_count = RelatedObjectCountField('dcim.device', 'role')
+    device_count = RelatedObjectCountField('devices')
-    virtualmachine_count = RelatedObjectCountField('virtualization.virtualmachine', 'role')
+    virtualmachine_count = RelatedObjectCountField('virtual_machines')
 
     class Meta:
         model = models.DeviceRole
@@ -287,8 +287,8 @@ class NestedDeviceRoleSerializer(WritableNestedSerializer):
 )
 class NestedPlatformSerializer(WritableNestedSerializer):
     url = serializers.HyperlinkedIdentityField(view_name='dcim-api:platform-detail')
-    device_count = RelatedObjectCountField('dcim.device', 'platform')
+    device_count = RelatedObjectCountField('devices')
-    virtualmachine_count = RelatedObjectCountField('virtualization.virtualmachine', 'platform')
+    virtualmachine_count = RelatedObjectCountField('virtual_machines')
 
     class Meta:
         model = models.Platform
@@ -445,7 +445,7 @@ class NestedInventoryItemSerializer(WritableNestedSerializer):
 )
 class NestedInventoryItemRoleSerializer(WritableNestedSerializer):
     url = serializers.HyperlinkedIdentityField(view_name='dcim-api:inventoryitemrole-detail')
-    inventoryitem_count = RelatedObjectCountField('dcim.inventoryitem', 'role')
+    inventoryitem_count = RelatedObjectCountField('inventory_items')
 
     class Meta:
         model = models.InventoryItemRole
@@ -490,7 +490,7 @@ class NestedVirtualChassisSerializer(WritableNestedSerializer):
 )
 class NestedPowerPanelSerializer(WritableNestedSerializer):
     url = serializers.HyperlinkedIdentityField(view_name='dcim-api:powerpanel-detail')
-    powerfeed_count = RelatedObjectCountField('dcim.powerfeed', 'power_panel')
+    powerfeed_count = RelatedObjectCountField('powerfeeds')
 
     class Meta:
         model = models.PowerPanel

netbox/dcim/api/serializers.py

@@ -144,12 +144,12 @@ class SiteSerializer(NetBoxModelSerializer):
     )
 
     # Related object counts
-    circuit_count = RelatedObjectCountField('circuits.circuit', 'terminations__site')
+    circuit_count = RelatedObjectCountField('circuit_terminations')
-    device_count = RelatedObjectCountField('dcim.device', 'site')
+    device_count = RelatedObjectCountField('devices')
-    prefix_count = RelatedObjectCountField('ipam.prefix', 'site')
+    prefix_count = RelatedObjectCountField('prefixes')
-    rack_count = RelatedObjectCountField('dcim.rack', 'site')
+    rack_count = RelatedObjectCountField('racks')
-    vlan_count = RelatedObjectCountField('ipam.vlan', 'site')
+    vlan_count = RelatedObjectCountField('vlans')
-    virtualmachine_count = RelatedObjectCountField('virtualization.virtualmachine', 'site')
+    virtualmachine_count = RelatedObjectCountField('virtual_machines')
 
     class Meta:
         model = Site
@@ -186,7 +186,7 @@ class RackRoleSerializer(NetBoxModelSerializer):
     url = serializers.HyperlinkedIdentityField(view_name='dcim-api:rackrole-detail')
 
     # Related object counts
-    rack_count = RelatedObjectCountField('dcim.rack', 'role')
+    rack_count = RelatedObjectCountField('racks')
 
     class Meta:
         model = RackRole
@@ -211,8 +211,8 @@ class RackSerializer(NetBoxModelSerializer):
     weight_unit = ChoiceField(choices=WeightUnitChoices, allow_blank=True, required=False, allow_null=True)
 
     # Related object counts
-    device_count = RelatedObjectCountField('dcim.device', 'rack')
+    device_count = RelatedObjectCountField('devices')
-    powerfeed_count = RelatedObjectCountField('dcim.powerfeed', 'rack')
+    powerfeed_count = RelatedObjectCountField('powerfeeds')
 
     class Meta:
         model = Rack
@@ -305,9 +305,9 @@ class ManufacturerSerializer(NetBoxModelSerializer):
     url = serializers.HyperlinkedIdentityField(view_name='dcim-api:manufacturer-detail')
 
     # Related object counts
-    devicetype_count = RelatedObjectCountField('dcim.devicetype', 'manufacturer')
+    devicetype_count = RelatedObjectCountField('device_types')
-    inventoryitem_count = RelatedObjectCountField('dcim.inventoryitem', 'manufacturer')
+    inventoryitem_count = RelatedObjectCountField('inventory_items')
-    platform_count = RelatedObjectCountField('dcim.platform', 'manufacturer')
+    platform_count = RelatedObjectCountField('platforms')
 
     class Meta:
         model = Manufacturer
@@ -345,7 +345,7 @@ class DeviceTypeSerializer(NetBoxModelSerializer):
     inventory_item_template_count = serializers.IntegerField(read_only=True)
 
     # Related object counts
-    device_count = RelatedObjectCountField('dcim.device', 'device_type')
+    device_count = RelatedObjectCountField('instances')
 
     class Meta:
         model = DeviceType
@@ -646,8 +646,8 @@ class DeviceRoleSerializer(NetBoxModelSerializer):
     config_template = NestedConfigTemplateSerializer(required=False, allow_null=True, default=None)
 
     # Related object counts
-    device_count = RelatedObjectCountField('dcim.device', 'role')
+    device_count = RelatedObjectCountField('devices')
-    virtualmachine_count = RelatedObjectCountField('virtualization.virtualmachine', 'role')
+    virtualmachine_count = RelatedObjectCountField('virtual_machines')
 
     class Meta:
         model = DeviceRole
@@ -663,8 +663,8 @@ class PlatformSerializer(NetBoxModelSerializer):
     config_template = NestedConfigTemplateSerializer(required=False, allow_null=True, default=None)
 
     # Related object counts
-    device_count = RelatedObjectCountField('dcim.device', 'platform')
+    device_count = RelatedObjectCountField('devices')
-    virtualmachine_count = RelatedObjectCountField('virtualization.virtualmachine', 'platform')
+    virtualmachine_count = RelatedObjectCountField('virtual_machines')
 
     class Meta:
         model = Platform
@@ -773,7 +773,7 @@ class VirtualDeviceContextSerializer(NetBoxModelSerializer):
     status = ChoiceField(choices=VirtualDeviceContextStatusChoices)
 
     # Related object counts
-    interface_count = RelatedObjectCountField('dcim.interface', 'vdcs')
+    interface_count = RelatedObjectCountField('interfaces')
 
     class Meta:
         model = VirtualDeviceContext
@@ -1106,7 +1106,7 @@ class InventoryItemRoleSerializer(NetBoxModelSerializer):
     url = serializers.HyperlinkedIdentityField(view_name='dcim-api:inventoryitemrole-detail')
 
     # Related object counts
-    inventoryitem_count = RelatedObjectCountField('dcim.inventoryitem', 'role')
+    inventoryitem_count = RelatedObjectCountField('inventory_items')
 
     class Meta:
         model = InventoryItemRole
@@ -1220,7 +1220,7 @@ class PowerPanelSerializer(NetBoxModelSerializer):
     )
 
     # Related object counts
-    powerfeed_count = RelatedObjectCountField('dcim.powerfeed', 'power_panel')
+    powerfeed_count = RelatedObjectCountField('powerfeeds')
 
     class Meta:
         model = PowerPanel

netbox/dcim/api/views.py

@@ -7,6 +7,7 @@ from rest_framework.response import Response
 from rest_framework.routers import APIRootView
 from rest_framework.viewsets import ViewSet
 
+from circuits.models import Circuit
 from dcim import filtersets
 from dcim.constants import CABLE_TRACE_SVG_DEFAULT_WIDTH
 from dcim.models import *
@@ -20,6 +21,7 @@ from netbox.api.viewsets.mixins import SequentialBulkCreatesMixin
 from netbox.constants import NESTED_SERIALIZER_PREFIX
 from utilities.api import get_serializer_for_model
 from utilities.query_functions import CollateAsChar
+from utilities.utils import count_related
 from . import serializers
 from .exceptions import MissingFilterException
 

netbox/extras/api/serializers.py

@@ -289,7 +289,7 @@ class TagSerializer(ValidatedModelSerializer):
     )
 
     # Related object counts
-    tagged_items = RelatedObjectCountField('extras.taggeditem', 'tag')
+    tagged_items = RelatedObjectCountField('extras_taggeditem_items')
 
     class Meta:
         model = Tag

netbox/ipam/api/nested_serializers.py

@@ -59,7 +59,7 @@ class NestedASNSerializer(WritableNestedSerializer):
 )
 class NestedVRFSerializer(WritableNestedSerializer):
     url = serializers.HyperlinkedIdentityField(view_name='ipam-api:vrf-detail')
-    prefix_count = RelatedObjectCountField('ipam.prefix', 'vrf')
+    prefix_count = RelatedObjectCountField('prefixes')
 
     class Meta:
         model = models.VRF
@@ -87,7 +87,7 @@ class NestedRouteTargetSerializer(WritableNestedSerializer):
 )
 class NestedRIRSerializer(WritableNestedSerializer):
     url = serializers.HyperlinkedIdentityField(view_name='ipam-api:rir-detail')
-    aggregate_count = RelatedObjectCountField('ipam.aggregate', 'rir')
+    aggregate_count = RelatedObjectCountField('aggregates')
 
     class Meta:
         model = models.RIR
@@ -133,8 +133,8 @@ class NestedFHRPGroupAssignmentSerializer(WritableNestedSerializer):
 )
 class NestedRoleSerializer(WritableNestedSerializer):
     url = serializers.HyperlinkedIdentityField(view_name='ipam-api:role-detail')
-    prefix_count = RelatedObjectCountField('ipam.prefix', 'role')
+    prefix_count = RelatedObjectCountField('prefixes')
-    vlan_count = RelatedObjectCountField('ipam.vlan', 'role')
+    vlan_count = RelatedObjectCountField('vlans')
 
     class Meta:
         model = models.Role
@@ -146,7 +146,7 @@ class NestedRoleSerializer(WritableNestedSerializer):
 )
 class NestedVLANGroupSerializer(WritableNestedSerializer):
     url = serializers.HyperlinkedIdentityField(view_name='ipam-api:vlangroup-detail')
-    vlan_count = RelatedObjectCountField('ipam.vlan', 'group')
+    vlan_count = RelatedObjectCountField('vlans')
 
     class Meta:
         model = models.VLANGroup

netbox/ipam/api/serializers.py

@@ -45,8 +45,8 @@ class ASNSerializer(NetBoxModelSerializer):
     tenant = NestedTenantSerializer(required=False, allow_null=True)
 
     # Related object counts
-    site_count = RelatedObjectCountField('dcim.site', 'asns')
+    site_count = RelatedObjectCountField('sites')
-    provider_count = RelatedObjectCountField('circuits.provider', 'asns')
+    provider_count = RelatedObjectCountField('providers')
 
     class Meta:
         model = ASN
@@ -94,8 +94,8 @@ class VRFSerializer(NetBoxModelSerializer):
     )
 
     # Related object counts
-    ipaddress_count = RelatedObjectCountField('ipam.ipaddress', 'vrf')
+    ipaddress_count = RelatedObjectCountField('ip_addresses')
-    prefix_count = RelatedObjectCountField('ipam.prefix', 'vrf')
+    prefix_count = RelatedObjectCountField('prefixes')
 
     class Meta:
         model = VRF
@@ -130,7 +130,7 @@ class RIRSerializer(NetBoxModelSerializer):
     url = serializers.HyperlinkedIdentityField(view_name='ipam-api:rir-detail')
 
     # Related object counts
-    aggregate_count = RelatedObjectCountField('ipam.aggregate', 'rir')
+    aggregate_count = RelatedObjectCountField('aggregates')
 
     class Meta:
         model = RIR
@@ -203,8 +203,8 @@ class RoleSerializer(NetBoxModelSerializer):
     url = serializers.HyperlinkedIdentityField(view_name='ipam-api:role-detail')
 
     # Related object counts
-    prefix_count = RelatedObjectCountField('ipam.prefix', 'role')
+    prefix_count = RelatedObjectCountField('prefixes')
-    vlan_count = RelatedObjectCountField('ipam.vlan', 'role')
+    vlan_count = RelatedObjectCountField('vlans')
 
     class Meta:
         model = Role
@@ -229,7 +229,7 @@ class VLANGroupSerializer(NetBoxModelSerializer):
     utilization = serializers.CharField(read_only=True)
 
     # Related object counts
-    vlan_count = RelatedObjectCountField('ipam.vlan', 'group')
+    vlan_count = RelatedObjectCountField('vlans')
 
     class Meta:
         model = VLANGroup
@@ -259,7 +259,7 @@ class VLANSerializer(NetBoxModelSerializer):
     l2vpn_termination = NestedL2VPNTerminationSerializer(read_only=True, allow_null=True)
 
     # Related object counts
-    prefix_count = RelatedObjectCountField('ipam.prefix', 'vlan')
+    prefix_count = RelatedObjectCountField('prefixes')
 
     class Meta:
         model = VLAN

netbox/netbox/api/fields.py

@@ -1,7 +1,6 @@
-from django.apps import apps
 from django.core.exceptions import ObjectDoesNotExist
-from drf_spectacular.utils import extend_schema_field
 from drf_spectacular.types import OpenApiTypes
+from drf_spectacular.utils import extend_schema_field
 from netaddr import IPNetwork
 from rest_framework import serializers
 from rest_framework.exceptions import ValidationError
@@ -146,13 +145,7 @@ class RelatedObjectCountField(serializers.ReadOnlyField):
     is detected by get_annotations_for_serializer() when determining the annotations to be added to a queryset
     depending on the serializer fields selected for inclusion in the response.
     """
-    def __init__(self, model, related_field, **kwargs):
+    def __init__(self, relation, **kwargs):
-        super().__init__(**kwargs)
+        self.relation = relation
 
-        # Set the model and field names passed on the field
+        super().__init__(**kwargs)
-        if type(model) is str:
-            app_label, model_name = model.split('.')
-            self.model = apps.get_model(app_label, model_name)
-        else:
-            self.model = model
-        self.related_field = related_field

netbox/tenancy/api/serializers.py

@@ -34,16 +34,16 @@ class TenantSerializer(NetBoxModelSerializer):
     group = NestedTenantGroupSerializer(required=False, allow_null=True)
 
     # Related object counts
-    circuit_count = RelatedObjectCountField('circuits.circuit', 'tenant')
+    circuit_count = RelatedObjectCountField('circuits')
-    device_count = RelatedObjectCountField('dcim.device', 'tenant')
+    device_count = RelatedObjectCountField('devices')
-    rack_count = RelatedObjectCountField('dcim.rack', 'tenant')
+    rack_count = RelatedObjectCountField('racks')
-    site_count = RelatedObjectCountField('dcim.site', 'tenant')
+    site_count = RelatedObjectCountField('sites')
-    ipaddress_count = RelatedObjectCountField('ipam.ipaddress', 'tenant')
+    ipaddress_count = RelatedObjectCountField('ip_addresses')
-    prefix_count = RelatedObjectCountField('ipam.prefix', 'tenant')
+    prefix_count = RelatedObjectCountField('prefixes')
-    vlan_count = RelatedObjectCountField('ipam.vlan', 'tenant')
+    vlan_count = RelatedObjectCountField('vlans')
-    vrf_count = RelatedObjectCountField('ipam.vrf', 'tenant')
+    vrf_count = RelatedObjectCountField('vrfs')
-    virtualmachine_count = RelatedObjectCountField('virtualization.virtualmachine', 'tenant')
+    virtualmachine_count = RelatedObjectCountField('virtual_machines')
-    cluster_count = RelatedObjectCountField('virtualization.cluster', 'tenant')
+    cluster_count = RelatedObjectCountField('clusters')
 
     class Meta:
         model = Tenant

netbox/utilities/api.py

@@ -17,6 +17,7 @@ from utilities.utils import count_related
 from .utils import dynamic_import
 
 __all__ = (
+    'get_annotations_for_serializer',
     'get_graphql_type_for_model',
     'get_prefetches_for_serializer',
     'get_serializer_for_model',
@@ -143,9 +144,12 @@ def get_annotations_for_serializer(serializer_class, fields_to_include=None):
     if not fields_to_include:
         fields_to_include = serializer_class.Meta.fields
 
+    model = serializer_class.Meta.model
+
     for field_name, field in serializer_class._declared_fields.items():
         if field_name in fields_to_include and type(field) is RelatedObjectCountField:
-            annotations[field_name] = count_related(field.model, field.related_field)
+            related_field = model._meta.get_field(field.relation).field
+            annotations[field_name] = count_related(related_field.model, related_field.name)
 
     return annotations
 

netbox/virtualization/api/nested_serializers.py

@@ -24,7 +24,7 @@ __all__ = [
 )
 class NestedClusterTypeSerializer(WritableNestedSerializer):
     url = serializers.HyperlinkedIdentityField(view_name='virtualization-api:clustertype-detail')
-    cluster_count = RelatedObjectCountField('virtualization.cluster', 'type')
+    cluster_count = RelatedObjectCountField('clusters')
 
     class Meta:
         model = ClusterType
@@ -36,7 +36,7 @@ class NestedClusterTypeSerializer(WritableNestedSerializer):
 )
 class NestedClusterGroupSerializer(WritableNestedSerializer):
     url = serializers.HyperlinkedIdentityField(view_name='virtualization-api:clustergroup-detail')
-    cluster_count = RelatedObjectCountField('virtualization.cluster', 'group')
+    cluster_count = RelatedObjectCountField('clusters')
 
     class Meta:
         model = ClusterGroup
@@ -48,7 +48,7 @@ class NestedClusterGroupSerializer(WritableNestedSerializer):
 )
 class NestedClusterSerializer(WritableNestedSerializer):
     url = serializers.HyperlinkedIdentityField(view_name='virtualization-api:cluster-detail')
-    virtualmachine_count = RelatedObjectCountField('virtualization.virtualmachine', 'cluster')
+    virtualmachine_count = RelatedObjectCountField('virtual_machines')
 
     class Meta:
         model = Cluster

netbox/virtualization/api/serializers.py

@@ -25,7 +25,7 @@ class ClusterTypeSerializer(NetBoxModelSerializer):
     url = serializers.HyperlinkedIdentityField(view_name='virtualization-api:clustertype-detail')
 
     # Related object counts
-    cluster_count = RelatedObjectCountField('virtualization.cluster', 'type')
+    cluster_count = RelatedObjectCountField('clusters')
 
     class Meta:
         model = ClusterType
@@ -39,7 +39,7 @@ class ClusterGroupSerializer(NetBoxModelSerializer):
     url = serializers.HyperlinkedIdentityField(view_name='virtualization-api:clustergroup-detail')
 
     # Related object counts
-    cluster_count = RelatedObjectCountField('virtualization.cluster', 'group')
+    cluster_count = RelatedObjectCountField('clusters')
 
     class Meta:
         model = ClusterGroup
@@ -58,8 +58,8 @@ class ClusterSerializer(NetBoxModelSerializer):
     site = NestedSiteSerializer(required=False, allow_null=True, default=None)
 
     # Related object counts
-    device_count = RelatedObjectCountField('dcim.device', 'cluster')
+    device_count = RelatedObjectCountField('devices')
-    virtualmachine_count = RelatedObjectCountField('virtualization.virtualmachine', 'cluster')
+    virtualmachine_count = RelatedObjectCountField('virtual_machines')
 
     class Meta:
         model = Cluster

netbox/vpn/api/nested_serializers.py

@@ -24,7 +24,7 @@ __all__ = (
 )
 class NestedTunnelGroupSerializer(WritableNestedSerializer):
     url = serializers.HyperlinkedIdentityField(view_name='vpn-api:tunnelgroup-detail')
-    tunnel_count = RelatedObjectCountField('vpn.tunnel', 'group')
+    tunnel_count = RelatedObjectCountField('tunnels')
 
     class Meta:
         model = models.TunnelGroup

netbox/vpn/api/serializers.py

@@ -31,7 +31,7 @@ class TunnelGroupSerializer(NetBoxModelSerializer):
     url = serializers.HyperlinkedIdentityField(view_name='vpn-api:tunnelgroup-detail')
 
     # Related object counts
-    tunnel_count = RelatedObjectCountField('vpn.tunnel', 'group')
+    tunnel_count = RelatedObjectCountField('tunnels')
 
     class Meta:
         model = TunnelGroup
@@ -62,7 +62,7 @@ class TunnelSerializer(NetBoxModelSerializer):
     )
 
     # Related object counts
-    terminations_count = RelatedObjectCountField('vpn.tunneltermination', 'tunnel')
+    terminations_count = RelatedObjectCountField('terminations')
 
     class Meta:
         model = Tunnel