Refactor REST API serializers to avoid circular imports

netbox/ipam/api/serializers_/asns.py

@@ -0,0 +1,78 @@
+from rest_framework import serializers
+
+from ipam.models import ASN, ASNRange, RIR
+from netbox.api.fields import RelatedObjectCountField
+from netbox.api.serializers import NetBoxModelSerializer
+from tenancy.api.serializers_.tenants import TenantSerializer
+
+__all__ = (
+    'ASNRangeSerializer',
+    'ASNSerializer',
+    'AvailableASNSerializer',
+    'RIRSerializer',
+)
+
+
+class RIRSerializer(NetBoxModelSerializer):
+    url = serializers.HyperlinkedIdentityField(view_name='ipam-api:rir-detail')
+
+    # Related object counts
+    aggregate_count = RelatedObjectCountField('aggregates')
+
+    class Meta:
+        model = RIR
+        fields = [
+            'id', 'url', 'display', 'name', 'slug', 'is_private', 'description', 'tags', 'custom_fields', 'created',
+            'last_updated', 'aggregate_count',
+        ]
+        brief_fields = ('id', 'url', 'display', 'name', 'slug', 'description', 'aggregate_count')
+
+
+class ASNRangeSerializer(NetBoxModelSerializer):
+    url = serializers.HyperlinkedIdentityField(view_name='ipam-api:asnrange-detail')
+    rir = RIRSerializer(nested=True)
+    tenant = TenantSerializer(nested=True, required=False, allow_null=True)
+    asn_count = serializers.IntegerField(read_only=True)
+
+    class Meta:
+        model = ASNRange
+        fields = [
+            'id', 'url', 'display', 'name', 'slug', 'rir', 'start', 'end', 'tenant', 'description', 'tags',
+            'custom_fields', 'created', 'last_updated', 'asn_count',
+        ]
+        brief_fields = ('id', 'url', 'display', 'name', 'description')
+
+
+class ASNSerializer(NetBoxModelSerializer):
+    url = serializers.HyperlinkedIdentityField(view_name='ipam-api:asn-detail')
+    rir = RIRSerializer(nested=True, required=False, allow_null=True)
+    tenant = TenantSerializer(nested=True, required=False, allow_null=True)
+
+    # Related object counts
+    site_count = RelatedObjectCountField('sites')
+    provider_count = RelatedObjectCountField('providers')
+
+    class Meta:
+        model = ASN
+        fields = [
+            'id', 'url', 'display', 'asn', 'rir', 'tenant', 'description', 'comments', 'tags', 'custom_fields',
+            'created', 'last_updated', 'site_count', 'provider_count',
+        ]
+        brief_fields = ('id', 'url', 'display', 'asn', 'description')
+
+
+class AvailableASNSerializer(serializers.Serializer):
+    """
+    Representation of an ASN which does not exist in the database.
+    """
+    asn = serializers.IntegerField(read_only=True)
+    description = serializers.CharField(required=False)
+
+    def to_representation(self, asn):
+        rir = RIRSerializer(self.context['range'].rir, nested=True, context={
+            'request': self.context['request']
+        }).data
+        return {
+            'rir': rir,
+            'asn': asn,
+        }