def create(self, validated_data):
usages = validated_data.pop('usages', [])
instance = super(PrefixSerializer, self).create(validated_data)
for usage in usages:
manage.PrefixUsage(prefix=instance, usage=usage).save()
return instance
def update(self, instance, validated_data):
if 'usages' in validated_data:
new_usages = set(u.id for u in validated_data.pop('usages'))
current_usages = set(u.id for u in instance.usages.all())
to_add = new_usages - current_usages
to_delete = current_usages - new_usages
for usage in to_add:
manage.PrefixUsage(
prefix=instance,
usage=manage.Usage.objects.get(pk=usage)).save()
manage.PrefixUsage.objects.filter(
prefix=instance, usage__in=list(to_delete)).delete()
return super(PrefixSerializer, self).update(instance, validated_data)