Example 5: Socket IO App

var io                                     = require(‘socket.io’)();

var _socket                        = ”;

//When new client is connected

io.on(‘connection’, function (socket) {

console.log(‘hello… you are connected (id=’ + socket.id + ‘).’);

_socket = socket;

//Receiving incoming message ‘message_reply’

socket.on(‘message_reply’, function(msg) {

console.info(‘message_reply : ‘+msg);

});

//When disconnect

socket.on(‘disconnect’, function() {

console.info(‘Socket id=’ + _socket.id + ‘ has gone.’);

});

});

// Listening to port 3000 for new connection and incoming message

io.listen(3000, function () {

console.log(‘Demo 5 – server with port : 3000’);

});

// Auto-send message to client every 5s

setInterval(function() {

var currentTime = new Date().toISOString();

console.log(‘Ping client : ‘+_socket.id+’ msg #’+currentTime);

_socket.emit(‘ping_client’, ‘Ping client : ‘+_socket.id+’ msg #’+currentTime);

}, 5000);

var io                     = require(‘socket.io-client’);

var client              = io.connect(‘http://localhost:3000’);

//Receiving incoming message ‘ping_client’

client.on(‘ping_client’, function(msg) {

console.info(‘Receiving ping message from server : ‘+msg);

//Send message to server

client.emit(‘message_reply’, ‘Hi server, got your message’);

console.info(‘Sending ack message to server’);

});