util.py 文件源码

def _validator_events(desc, key, validator, include_removes):
    """Runs a validation method on an attribute value to be set or appended."""

    if include_removes:
        def append(state, value, initiator):
            return validator(state.obj(), key, value, False)

        def set_(state, value, oldvalue, initiator):
            return validator(state.obj(), key, value, False)

        def remove(state, value, initiator):
            validator(state.obj(), key, value, True)
    else:
        def append(state, value, initiator):
            return validator(state.obj(), key, value)

        def set_(state, value, oldvalue, initiator):
            return validator(state.obj(), key, value)

    event.listen(desc, 'append', append, raw=True, retval=True)
    event.listen(desc, 'set', set_, raw=True, retval=True)
    if include_removes:
        event.listen(desc, "remove", remove, raw=True, retval=True)