Server sourceDisconnect

sourceDisconnect.js

var sourceDisconnect = Rx.Observable.create(function(observer) {
    io.on('connection', function(socket) {                
        socket.on('disconnect', function(data) {
            observer.onNext({'socketId': socket.id, 'event': 'client disconnect'});       
        });
    });
});

var observerDisconnect = sourceDisconnect
.subscribe(function(obj) { 
    var socketId = obj.socketId;
    var user = usersMap.get(socketId);
    usersMap = usersMap.delete(obj.socketId);
    io.emit('all users', usersMap.toArray());
});