Http is a stateless protocol. So, after each request cycle , a new connection needs to be established. It is ok for normal website but for chat application, we need a continuous connection to be established.Here we have code for simple socket programming with socket.io module
var socketio = require('socket.io');
var http = require('http');
var fs = require('fs');
var conn = http.createServer(function(req,res){
res.writeHead(200,{"Content-type" :"text/html"});
res.end(fs.readFileSync(__dirname+'/index.html'))
})
conn.listen(8082,function(){
console.log('Connected')
})
socketio.listen(conn).on('connection',function(socket){
socket.on('clientmessage',function(msg){
socket.emit("Message from client "+msg)
})
})
<html>
<head>
<scriptsrc="http://ajax.googleapis.com/ajax/libs/jquery/1.7.2/jquery.min.js"></script>
<scriptsrc="/socket.io/socket.io.js"></script>
<script>
$(function(){
variosocket = io.connect();
iosocket.on('connect', function () {
$('#incomingChatMessages').append($('<li>Connected</li>'));
iosocket.on('message', function(message) {
$('#incomingChatMessages').append($('<li></li>').text(message));
});
iosocket.on('disconnect', function() {
$('#incomingChatMessages').append('<li>Disconnected</li>');
});
});
$('#outgoingChatMessage').keypress(function(event) {
if(event.which == 13) {
event.preventDefault();
iosocket.send($('#outgoingChatMessage').val());
$('#incomingChatMessages').append($('<li></li>').text($('#outgoingChatMessage').val()));
$('#outgoingChatMessage').val('');
}
});
});
</script>
</head>
<body>
Incoming Chat: <ul id="incomingChatMessages"></ul>
<br />
<input type="text" id="outgoingChatMessage">
</body>
</html>
By Pankaj Kumar Agarwal
