socket.io signalling server

server.js

/*jslint node: true */
(function (){
  'use strict';

  var nodeStatic = require('node-static');
  var http = require('http');
  var io = require('socket.io')();

  var server = new(nodeStatic.Server)();
  var app = http.createServer(function (request, response) {
      server.serve(request, response);
  });

  app.listen(1337);
  io.listen(app);

  // Allows debouncing of functions, to stop event spam
  function debounce(fn, delay) {
    var timer = null;
    return function () {
      var context = this, args = arguments;
      clearTimeout(timer);
      timer = setTimeout(function () {
        fn.apply(context, args);
      }, delay);
    };
  }
  // Since we can't do clients.length in Socket.io 1+, this will give us the count
  var getClientsForRoom = function (roomId, namespace) {
    var res = [],
    ns = io.of(namespace ||'/');    // the default namespace is '/'

    if (ns) {
      for (var id in ns.connected) {
        if(roomId) {
          var index = ns.connected[id].rooms.indexOf(roomId) ;
          if(index !== -1) {
            res.push(ns.connected[id]);
          }
        } else {
          res.push(ns.connected[id]);
        }
      }
    }
    return res;
  };

  io.sockets.on('connection', function (socket){
    var log = function () {
      var messages = ['>>> Message from server: '];
      for (var i = 0; i < arguments.length; i++) {
        messages.push(arguments[i]);
      }
      socket.emit('log', messages);
    };
    socket.on('error', function (err) {
      console.log(err);
    });

    socket.on('message', function (message) {
      log('Got message:', message);
      socket.broadcast.emit('message', message);
    });

    socket.on('create or join', function (room) {
      var clients = getClientsForRoom(room);
      var numClients = Object.keys(clients).length;

      log('Room ' + room + ' has ' + numClients + ' client' + ( numClients === 1 ? '' : 's' ));
      log('Request to create or join room ' + room);

      if (numClients === 0){
        socket.join(room);
        socket.emit('created', room);
        log('Created a room: ', room);
      } else if (numClients >= 1) {
        io.sockets.in(room).emit('join', room);
        socket.join(room);
        socket.emit('joined', room);
        log('Joined a room: ', room);
      }
      socket.emit('emit(): client ' + socket.id + ' joined room ' + room);
      socket.broadcast.emit('broadcast(): client ' + socket.id + ' joined room ' + room);
    });
    // Sends slide change event to all clients
    socket.on('changeSlide', function (slide) {
      log('Asked to change to slide', slide);
      socket.broadcast.emit('changeSlide', slide);
      socket.emit('changeSlide', slide);
    });
    // Sends rotate data to all clients
    socket.on('rotate', debounce(function (data) {
      log('Rotation data: ', data);
      socket.broadcast.emit('rotate', data);
      socket.emit('rotate', data);
    }, 50));

  });
}());