fastadmin后台使用websocket

直接使用gatewayworker。

在backend-init.js中：
断线重连、心跳检测

define(['backend'], function (Backend) {
    var socket; //websocket的实例
    var lockReconnect = false; //避免重复连接
    reconnect();
    function getwebsocket() { //新建websocket的函数 页面初始化 断开连接时重新调用
        var wsUrl = 'ws://47.56.127.188:8384';
        socket = new WebSocket(wsUrl);
        socket.onerror = function(event) {
            //console.log('websocket服务出错了');
            reconnect(wsUrl);
        };
        socket.onclose = function(event) {
            //console.log('websocket服务关闭了');
            reconnect(wsUrl);
        };
        socket.onopen = function(event) {
            heartCheck.reset().start(); //传递信息
        };
        socket.onmessage = function(event) {
            //如果获取到消息，心跳检测重置
            //拿到任何消息都说明当前连接是正常的
            //接受消息后的UI变化
            var tmp = eval('(' + event.data + ')');
            var type = tmp.type;
            var action = tmp.action;
            //最新通知推送（给所有在线用户推送的）
            if (type == 'notice' && action == 'withdraw') {
                var alertSound = new Audio('/public/assets/audio/withdraw.mp3');
                alertSound.play();
            }
            if (type == 'notice' && action == 'recharge') {
                var alertSound = new Audio('/public/assets/audio/recharge.mp3');
                alertSound.play();
            }
            heartCheck.reset().start();
        };
    }

    function reconnect(url) {
        if (lockReconnect) return;
        lockReconnect = true;
        //没连接上会一直重连，设置延迟避免请求过多
        setTimeout(function() {
            getwebsocket();
            lockReconnect = false;
        }, 2000);
    }
    //心跳检测
    var heartCheck = {
        timeout: 60000, //60秒
        timeoutObj: null,
        serverTimeoutObj: null,
        reset: function() {
            clearTimeout(this.timeoutObj);
            clearTimeout(this.serverTimeoutObj);
            return this;
        },
        start: function() {
            var self = this;
            this.timeoutObj = setTimeout(function() {
                //这里发送一个心跳，后端收到后，返回一个心跳消息，
                //onmessage拿到返回的心跳就说明连接正常
                socket.send("心跳测试");
                self.serverTimeoutObj = setTimeout(function() { //如果超过一定时间还没重置，说明后端主动断开了
                    socket.close(); //如果onclose会执行reconnect，我们执行ws.close()就行了.如果直接执行reconnect 会触发onclose导致重连两次
                }, self.timeout);
            }, this.timeout);
        }
    };
});