How to handle asynchronous in Javascript?

Question

Asynchronous in Socket.io

I use 2 variables online (to count the number of online people currently) and total variable (count the total number of people visited). The problem is that when I reload page continuously online variable has not decreased, it has increased.

io.on('connection', function(sock) {

    sock.on('disconnect', function() {
        sock.broadcast.emit('Client-disconnect', --online);
    })
    io.sockets.emit('Client-connection',{ onl: ++online, tol: ++total });
}

that suggests `sock.on('disconnect'` isn't called - can you add some debugging to test this — Jaromanda X, Aug 20 '17 at 08:41
The Best Explanation for your query: https://stackoverflow.com/questions/14220321/how-do-i-return-the-response-from-an-asynchronous-call — Vijay Krishna, Oct 23 '17 at 11:53

score 1 · Accepted Answer · answered Aug 20 '17 at 08:48

The connections are being left open as they are not closed when the page is either refreshed or closed. Listen to the page events to be able to close the connection before the page is removed:

window.onbeforeunload = function(e) { sock.disconnect(); };

How to handle asynchronous in Javascript?

1 Answers1