app.js

// Based on the tutorial:
// http://tutorialzine.com/2012/08/nodejs-drawing-game/

//Restrictions on HEROKU:
// Doesn't support installing dependencies with npm with node 0.8
// Doesn't support websocekts.

// Including libraries

var app = require('http').createServer(handler),
	io = require('socket.io').listen(app),
	nstatic = require('node-static'); // for serving files

// This will make all the files in the current folder
// accessible from the web
var fileServer = new nstatic.Server('./');
	
// This is the port for our web server.
// you will need to go to http://localhost:3000 to see it
var port = process.env.PORT || 80; // Cloud9 + Heroku || localhost
app.listen(port);

// If the URL of the socket server is opened in a browser
function handler (request, response) {
	request.addListener('end', function () {
        fileServer.serve(request, response);
    });
}

// Delete this row if you want to see debug messages
io.set('log level', 1);

// Heroku doesn't support websockets so...
// Detect if heroku via config vars
// https://devcenter.heroku.com/articles/config-vars
// heroku config:add HEROKU=true --app node-drawing-game
if (process.env.HEROKU === 'true') {
    io.configure(function () {
        io.set("transports", ["xhr-polling"]);
        io.set("polling duration", 10);
    });
}

// Listen for incoming connections from clients
io.sockets.on('connection', function (socket) {

	// Start listening for mouse move events
	socket.on('mousemove', function (data) {
		
		// This line sends the event (broadcasts it)
		// to everyone except the originating client.
		socket.broadcast.emit('moving', data);
	});
});