videochat-index.js

//Initializing Express and other dependencies
...
...

var io = socketIO(server);

//Implementing Socket.io
//connection is a synonym of reserved event connect
//connection event is fired as soon as a client connects to this socket.
io.sockets.on('connection', function(socket) {

	// Convenience function to log server messages on the client.
	// Arguments is an array like object which contains all the arguments of log(). 
	// To push all the arguments of log() in array, we have to use apply().
	function log() {
	  var array = ['Message from server:'];
	  array.push.apply(array, arguments);
	  socket.emit('log', array);
	}
  
    
  //Defining Server behavious on Socket Events
  socket.on('message', function(message, room) {
	  log('Client said: ', message);
    //server should send the receive only in room
	  socket.in(room).emit('message', message, room);
	});
  
	//Event for joining/creating room
  socket.on('create or join', function(room) {
	  log('Received request to create or join room ' + room);
  
	  //Finding clients in the current room
    var clientsInRoom = io.sockets.adapter.rooms[room];
	  var numClients = clientsInRoom ? Object.keys(clientsInRoom.sockets).length : 0;
	  log('Room ' + room + ' now has ' + numClients + ' client(s)');
  
    //If no client is in the room, create a room and add the current client
	  if (numClients === 0) {
		  socket.join(room);
		  log('Client ID ' + socket.id + ' created room ' + room);
		  socket.emit('created', room, socket.id);
	  } 
    
    //If one client is already in the room, add this client in the room
    else if (numClients === 1) {
		  log('Client ID ' + socket.id + ' joined room ' + room);
		  io.sockets.in(room).emit('join', room);
		  socket.join(room);
		  socket.emit('joined', room, socket.id);
		  io.sockets.in(room).emit('ready');
	  }
    
    //If two clients are already present in the room, do not add the current client in the room
    else { // max two clients
		  socket.emit('full', room);
	  }
	});
  
  //Utility event 
	socket.on('ipaddr', function() {
	  var ifaces = os.networkInterfaces();
	  for (var dev in ifaces) {
		ifaces[dev].forEach(function(details) {
		  if (details.family === 'IPv4' && details.address !== '127.0.0.1') {
			socket.emit('ipaddr', details.address);
		  }
		});
	  }
	});
  
  //Event for notifying other clients when a client leaves the room
	socket.on('bye', function(){
	  console.log('received bye');
	});
  
  });