✨ Rewrite websocket demo

Author: jysperm

README.md

@@ -39,6 +39,7 @@ app.use('/wechat', require('./routes/wechat-message-callback'))
 | 文件名        | 介绍 |
 | ------------  | ---- |
 | [wechat-message-callback.js](https://github.com/leancloud/leanengine-nodejs-demos/blob/master/routes/wechat-message-callback.js) | 接收并自动回复 [微信公众平台的用户消息回调](https://mp.weixin.qq.com/wiki?t=resource/res_main&id=mp1421140543)  |
+| [websocket.js](https://github.com/leancloud/leanengine-nodejs-demos/blob/master/routes/websocket.js) | 简单的 WebSocket 示例：将客户端发来的消息原样发回客户端（echo）、每隔一秒向客户端发送一条消息（timer） |
 
 ## 其他 Demo
 

app.js

@@ -1,17 +1,16 @@
+const AV = require('leanengine')
+const bodyParser = require('body-parser')
 const express = require('express')
-const timeout = require('connect-timeout')
 const path = require('path')
-const bodyParser = require('body-parser')
-const AV = require('leanengine')
-const expressWs = require('express-ws')
+const timeout = require('connect-timeout')
 
 // 加载云函数定义，你可以将云函数拆分到多个文件方便管理，但需要在主文件中加载它们
 require('./cloud')
 
 const app = express()
 
 // 启用 WebSocket 支持，如不需要可去除
-expressWs(app)
+require('express-ws')(app)
 
 // 设置模板引擎
 app.set('views', path.join(__dirname, 'views'))

routes/websocket.js

@@ -1,22 +1,42 @@
-var express = require('express');
-var expressWs = require('express-ws');
+var {Router} = require('express')
 
-var router = express.Router();
+const router = module.exports = new Router
 
 /*
  * WebSocket 示例
  *
- * 你还需要在 app.js 中添加 `expressWs(app);`
+ * 注意检查 app.js 中需要有 `require('express-ws')(app)`
+ *
+ * 可以使用 wscat 或 websocat 来对 WebSocket API 进行测试
+ * https://github.com/websockets/wscat
+ * https://github.com/vi/websocat
+ *
+ * 安装依赖：
+ *
+ *   npm install express-ws
+ *
  */
 
-router.get('/', (req, res) => {
-  res.render('websocket.ejs');
-});
-
+/*
+ * 将客户端发来的消息原样发回客户端
+ * wscat -c ws://localhost:3000/websocket/echo
+*/
 router.ws('/echo', (ws, req) => {
   ws.on('message', (msg) => {
-    ws.send(msg);
-  });
-});
+    ws.send(msg)
+  })
+})
+
+/*
+ * 每隔一秒向客户端发送一条消息
+ * wscat -c ws://localhost:3000/websocket/timer
+*/
+router.ws('/timer', (ws, req) => {
+  const intervalId = setInterval( () => {
+    ws.send('Hello')
+  }, 1000)
 
-module.exports = router;
+  ws.on('close', (msg) => {
+    clearInterval(intervalId)
+  })
+})