Zrobiłem prosty licznik odwiedzin w czasie rzeczywistym.

Możesz go pobrać zto repozytorium.

Dzieje się tak, że zdarzenie rozłączenia (nawet po zamknięciu przeglądarki) na serwerze nigdy nie jest uruchamiane.

server.js to:

<code>(function () {
var app, count, express, io;

express = require('express');
io = require('socket.io');

app = module.exports = express.createServer();

app.configure(function () {
    app.set('views', __dirname + '/views');
    app.set('view engine', 'jade');
    app.use(express.bodyParser());
    app.use(express.methodOverride());
    app.use(require('stylus').middleware({
        src: __dirname + '/public'
    }));
    app.use(app.router);
    return app.use(express.static(__dirname + '/public'));
});

app.configure('development', function () {
    return app.use(express.errorHandler({
        dumpExceptions: true,
        showStack: true
    }));
});
app.configure('production', function () {
    return app.use(express.errorHandler());
});

io = require('socket.io').listen(app);

count = 0;

io.sockets.on('connection', function (socket) {
    count++;
    io.sockets.emit('count', {
        number: count
    });
});

io.sockets.on('disconnect', function () {
    console.log('DISCONNESSO!!! ');
    count--;
    io.sockets.emit('count', {
        number: count
    });
});


app.get('/', function (req, res) {
    return res.render('index', {
        title: 'node.js express socket.io counter'
    });
});
if (!module.parent) {
    app.listen(10927);
    console.log("Express server listening on port %d", app.address().port);
}

}).call(this);
</code>

Skrypt na kliencie to:

<code>    script(type='text/javascript')

        var socket = io.connect();

        socket.on('count', function (data) {
            $('#count').html( data.number );
        });
</code>