socket.on('connection' … event never fired

Question

Problem socket.io NOT working

Details

• Generated a project with express [folder]; cd [folder]; npm install;
• Setup socket.io npm install socket.io
• Run node app with below code
• Client connect event fires but server connection NEVER fired.

Setup

• Server AWS Free Tier, Ubuntu 11.10, ami-a7f539ce
• nodejs v0.6.5
• express v2.5.1
• socket.io v0.8.7

Client

 var socket = io.connect('http://example.com:3000');

 socket.on('connect', function() { 
    console.log('connected');
 });

 socket.on('message', function(msg){
    console.log(msg);
 });

 socket.on('disconnect', function() {
    console.log('disconnected');
 });

 socket.on('error', function (e) {
    console.log('System', e ? e : 'A unknown error occurred');
 });

Server

 [...]

 app.listen(3000);

 // socket.io setup
 var socket = require('socket.io').listen(app);

 // socket.io connection establishment
 socket.on('connection', function (client) {
    client.send("hello");
    console.log("hello", client);           
 });

Why is connection event never fired?

Answer 1

Ricardo Tomasi is correct, saved my life, i was going crazy.

Altough things changed, we are in 2013, there's still an issue opened (since 2 years) on this

probably something changed, anyway to register the 'connect' event i had to do this:

var openSocket = function (uniqueID) {
  var appSocket = io.connect('/'+uniqueID, { transports: ['websocket', 'xhr-polling']});
  appSocket.socket.on('connect', function () {
    console.log('i did connect.');
  });
  return appSocket;
};

Answer 2

Took a while to notice... the connection event is emmited on io.sockets. In your code this would be

socket.sockets.on('connection', function (client) {
  client.send("hello")
  console.log("hello", client)
})

You should use io instead of socket as the var name to avoid this confusion.

Answer 3

The following did a trick for me with: socket.io-client: "^0.9.16"

io.connect("http://localhost:4000", {'force new connection': true});

Now 'connect' event fires consistently and there is no re-use.

I figured out this option by examining socket.io-client/lib/io.js line: 192 Since I can't even find this io.js file in github, I think there is refactoring in future releases, and this option might not work.

At least this might be helpful to somebody who will take this temporary work around.