微信小程序 SocketIO 实例讲解

const emitter = require('./emitter.js');/** socket.io 协议常量 */var packets = {  open:   0  // non-ws , close:  1  // non-ws , ping:   2 , pong:   3 , message: 4 , upgrade: 5 , noop:   6};var events = {   CONNECT: 0,  DISCONNECT: 1,  EVENT: 2,  ACK: 3,  ERROR: 4,  BINARY_EVENT: 5,  BINARY_ACK: 6};const PING_CHECK_INTERVAL = 2000;class WxSocketIO {  connect(url) {    return new Promise((resolve, reject) => {      wx.onSocketOpen((response) => {        this.isConnected = true;        //this.ping();        resolve(response);      });      wx.onSocketError(error => {        if (this.isConnected) {          this.fire('error', error);        } else {          reject(error);        }      });      wx.onSocketMessage(message => this._handleMessage(message));      wx.onSocketClose(result => {        if (this.isConnected) {          this.fire('error', new Error("The websocket was closed by server"));        } else {          this.fire('close');        }        this.isConnected = false;        this.destory();      });      wx.connectSocket({        url: `${url}/?EIO=3&transport=websocket`      });    });  }  ping() {    setTimeout(() => {      if (!this.isConnected) return;      wx.sendSocketMessage({        data: [packets.ping, 'probe'].join('')      });    }, PING_CHECK_INTERVAL);  }  close() {    return new Promise((resolve, reject) => {      if (this.isConnected) {        this.isConnected = false;        wx.onSocketClose(resolve);        wx.closeSocket();      } else {        reject(new Error('socket is not connected'));      }    });  }  emit(type, ...params) {    const data = [type, ...params];    wx.sendSocketMessage({      data: [packets.message, events.EVENT, JSON.stringify(data)].join("")    });  }  destory() {    this.removeAllListeners();  }  _handleMessage({ data }) {    const [match, packet, event, content] = /^(/d)(/d?)(.*)$/.exec(data);    if (+event === events.EVENT) {      switch (+packet) {        case packets.message:          let pack;          try {            pack = JSON.parse(content);          } catch (error) {            console.error('解析 ws 数据包失败：')            console.error(error);          }          const [type, ...params] = pack;          this.fire(type, ...params);          break;      }    }    else if (+packet == packets.pong) {      this.ping();    }  }};emitter.setup(WxSocketIO.prototype);module.exports = WxSocketIO;

const opts = {}const socket = this.globalData.socket = new WxSocketIO()socket.connect('ws://chat.socket.io', opts).then(_ => { console.info('App::WxSocketIO::onOpen') console.info('App:onShow:', that.globalData)}).catch(err => { console.error('App::WxSocketIO::onError', err)})其中socket.connect(ws_url, opts)中，opts目前可选值是path，用来指定使用socket.io时默认的path，比如设置opts为下列值：{ query: 'fanweixiao', with: 'mia&una',}