'If source_library_id or capa_type has been edited, refresh_children automatically.'

def editor_saved(self, user, old_metadata, old_content):

    old_source_library_id = old_metadata.get('source_library_id', [])
    if ((old_source_library_id != self.source_library_id) or (old_metadata.get('capa_type', ANY_CAPA_TYPE_VALUE) != self.capa_type)):
        try:
            self.refresh_children()
        except ValueError:
            pass
