概述

有些场景我们需要拦截或监听部分上行或者下行消息。

上行消息拦截

利用自定义路由器实现(RouteHandler)

实现自定义路由器

func (this *Gate) OnRoute(session gate.Session, topic string, msg []byte) (bool, interface{}, error) {
    needreturn := true
    u, err := url.Parse(topic)
    if err != nil {
        return needreturn, nil, errors.Errorf("topic is not uri %v", err.Error())
    }
    if strings.HasPrefix(topic, "account://modulus/init_by_deviceid") {
        //拦截协议
        message := map[string]interface{}{}
        err := json.Unmarshal(msg, &message)
        if err != nil {
            return needreturn, "", err
        }
        r, errstr := this.init_by_deviceid(session, message)
        if errstr != "" {
            return needreturn, "", errors.Errorf(errstr)
        }
        return needreturn, r, nil
    }else {
        //利用UriRoute将消息转发至后端模块,也可以实现自己的Route规则
        return this.Route.OnRoute(session, topic, msg)
    }
    return needreturn, "success", nil
}

替换默认的gate路由规则

func (this *Gate) OnInit(app module.App, settings *conf.ModuleSettings) {
    this.Gate.OnInit(this, app, settings,
        gate.SetRouteHandler(OnRoute),
    )
}

下行消息拦截

可以通过SendMessageHook替换下行消息体(Body),也可以直接拦截不允许发送

func (this *Gate) OnInit(app module.App, settings *conf.ModuleSettings) {
    this.Gate.OnInit(this, app, settings,
        gate.SetSendMessageHook(func(session gate.Session, topic string, msg []byte) (bytes []byte, e error) {
            return nil, errors.New("本协议不允许发送给客户端")
        }),
    )
}