'Add the necessary triggers to invalidate/recompute ``self``.'

def setup_triggers(self, model):

    for (model, field, path) in self.resolve_deps(model):
        if (field is not self):
            path_str = (None if (path is None) else ('.'.join(path) or 'id'))
            model._field_triggers.add(field, (self, path_str))
        elif path:
            self.recursive = True
            model._field_triggers.add(field, (self, '.'.join(path)))
