SocketIO Disconnected : From https://stackoverflow.com/questions/17287330/socket-io-handling-disconnect-event?answertab=votes#tab-top
var allClients = [];
io.sockets.on('connection', function(socket) {
allClients.push(socket);
socket.on('disconnect', function() {
console.log('Got disconnect!');
var i = allClients.indexOf(socket);
delete allClients[i];
});
});