def _pre_save(self, **kwargs): #signal, sender, instance):
        tags = self._get_instance_tag_cache(kwargs['instance'])
        tags = parse_tag_input(tags)

        #print 'Tags before: %s' % tags
        instance = kwargs['instance']
        self._set_instance_tag_cache(
            instance, edit_string_for_tags(tags))
Save tags back to the database
dataset/ETHPy150Open hzlf/openbroadcast/website/tagging_ng/fields.py/TagField._pre_save