postal.js/example/node/node_modules/socket.io/examples/chat/app.js

/**
 * Module dependencies.
 */

var express = require( 'express' )
	, stylus = require( 'stylus' )
	, nib = require( 'nib' )
	, sio = require( '../../lib/socket.io' );

/**
 * App.
 */

var app = express.createServer();

/**
 * App configuration.
 */

app.configure( function () {
	app.use( stylus.middleware( { src : __dirname + '/public', compile : compile } ) );
	app.use( express.static( __dirname + '/public' ) );
	app.set( 'views', __dirname );
	app.set( 'view engine', 'jade' );

	function compile( str, path ) {
		return stylus( str )
			.set( 'filename', path )
			.use( nib() );
	}

	;
} );

/**
 * App routes.
 */

app.get( '/', function ( req, res ) {
	res.render( 'index', { layout : false } );
} );

/**
 * App listen.
 */

app.listen( 3000, function () {
	var addr = app.address();
	console.log( '   app listening on http://' + addr.address + ':' + addr.port );
} );

/**
 * Socket.IO server (single process only)
 */

var io = sio.listen( app )
	, nicknames = {};

io.sockets.on( 'connection', function ( socket ) {
	socket.on( 'user message', function ( msg ) {
		socket.broadcast.emit( 'user message', socket.nickname, msg );
	} );

	socket.on( 'nickname', function ( nick, fn ) {
		if ( nicknames[nick] ) {
			fn( true );
		} else {
			fn( false );
			nicknames[nick] = socket.nickname = nick;
			socket.broadcast.emit( 'announcement', nick + ' connected' );
			io.sockets.emit( 'nicknames', nicknames );
		}
	} );

	socket.on( 'disconnect', function () {
		if ( !socket.nickname ) {
			return;
		}

		delete nicknames[socket.nickname];
		socket.broadcast.emit( 'announcement', socket.nickname + ' disconnected' );
		socket.broadcast.emit( 'nicknames', nicknames );
	} );
} );