websocket.io is raising on method of undefined error

Question

code

var express = require('express')
    , wsio = require('websocket.io');

/**
 * Create express app.
 */
var app = express.createServer();

/**
 * Listen
 */
app.listen(3000);


/**
 * Attach websocket server.
 */

var ws = wsio.attach(app);

/**
 * Serve your code
 */
app.use(express.static('public'));

/**
 * Listening on connections
 */
ws.on('connection', function (socket) {
    //listen on the message event and send it back
    // socket.on('message', function (msg) {
    //  console.log('   \033[96mgot:\033[39m    ' + msg);
    //  socket.send('pong');
    // });  

});

i am getting this error

.io\lib\protocols\hybi-16.js:39
    .on('text', function (packet) {
     ^
TypeError: Object #<Receiver> has no method 'on'
    at new WebSocket (H:\wamp\www\practices\nodejs\smashing\chapter10-websocket\
node_modules\websocket.io\lib\protocols\hybi-16.js:39:6)
    at Server.createClient (H:\wamp\www\practices\nodejs\smashing\chapter10-webs
ocket\node_modules\websocket.io\lib\server.js:88:10)
    at Server.handleUpgrade (H:\wamp\www\practices\nodejs\smashing\chapter10-web
socket\node_modules\websocket.io\lib\server.js:60:21)
    at HTTPServer.<anonymous> (H:\wamp\www\practices\nodejs\smashing\chapter10-w
ebsocket\node_modules\websocket.io\lib\websocket.io.js:92:8)
    at HTTPServer.EventEmitter.emit (events.js:106:17)
    at Socket.socket.ondata (http.js:1986:14)
    at TCP.onread (net.js:525:27)

Answer 1

You may be using an old version of express. createServer is deprecated. And express >=3.x does not return an http server. So there maybe no http server attached, which throws you that error.

express itself requires to be attached to http server. So update the library and code to the recent standards. See this