Vb - Count users on page

This can be quite tricky. How do you know when someone is still on the page? Someone might have visited the page and immediately closed their browser... how will you know that they are no longer on the page? Or if they navigate onto another page... how will you know?

One mechanism you can consider is to generate a serial number (maybe using a GUID string), then have a Javascript that polls the server every few seconds (say every 3 seconds) and all that it does is to send back that same GUID to the server. On the server, you can perhaps have a DataTable in which you store the GUID and the last time you "heard" from that GUID... You can regularly clear out (from the datatable) any GUID values that havent "spoken" to the server in say 10 seconds... A count of the number of rows in that DataTable then becomes the number of people still on the page (relatively accurate within the last 4-6 seconds). It is very imprecise, but might do the trick...

This mechanism is also not without problems, for the number of connections that it opens and closes every so often with the server. Have a look at this (for other technical considerations) http://query7.com/avoiding-long-polling

The jQuery snippet below polls the server every 3 seconds for new information and displays it in a simple alert box.

function callComplete(response) {
	alert("Response received is: "+response);
};

function connect() {
	// when the call completes, callComplete() will be called along with
	// the response returned
	$.post('/path/to/script.php', {}, callComplete, 'json');
};

$(document).ready( function() {
	setInterval(connect,3000);
}

Select allOpen in new window

Sounds like a very coplex way about it... as u see on my other question i have been able to record views and delete them on other pages but the whole browser closing is the issue.

It must be done as i have seen it used in other places and i know php can do it very well

my other option is on every page to record the page the user visited last and at what time... then run a query of the page from the last 10 seconds and make anote of that