refactor to handle M2M validation in ValidatedModelSerializer

netbox/dcim/api/serializers.py

@@ -734,30 +734,13 @@ class WritableInterfaceSerializer(ValidatedModelSerializer):
         # Validate that all untagged VLANs either belong to the same site as the Interface's parent Deivce or
         # VirtualMachine, or are global.
         parent = self.instance.parent if self.instance else data.get('device') or data.get('virtual_machine')
-        tagged_vlans = data.pop('tagged_vlans', [])
-        for vlan in tagged_vlans:
+        for vlan in data.get('tagged_vlans', []):
             if vlan.site not in [parent, None]:
                 raise serializers.ValidationError(
                     "Tagged VLAN {} must belong to the same site as the interface's parent device/VM, or it must be "
                     "global".format(vlan)
                 )
-
-        validated_data = super(WritableInterfaceSerializer, self).validate(data)
-        if tagged_vlans:
-            validated_data['tagged_vlans'] = tagged_vlans
-        return validated_data
-
-    def create(self, validated_data):
-        """
-        Becasue tagged_vlans is a M2M relationship, we have to create the interface first
-        """
-        tagged_vlans = validated_data.pop('tagged_vlans', None)
-        interface = Interface.objects.create(**validated_data)
-        interface.save()
-        if tagged_vlans:
-            interface.tagged_vlans = tagged_vlans
-            interface.save()
-        return interface
+        return data
 
 
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