from typing import Type from dcim.models import DeviceRole from django.contrib.contenttypes.models import ContentType from django.db.models.signals import pre_delete from django.dispatch import receiver from netbox_topology_views.models import RoleImage @receiver(pre_delete, sender=DeviceRole, dispatch_uid="delete_hanging_role_image") def delete_hanging_role_image(sender: Type[DeviceRole], instance: DeviceRole, **kwargs): ct = ContentType.objects.get_for_model(sender) RoleImage.objects.filter(content_type=ct, object_id=instance.id).delete()