[Hyde]

I don't have a lot of experience with JavaScript so someone will probably have a better idea than mine, but there are many timer scripts for JavaScript. You could start one every time the page loads and pass the time to PHP by putting a variable in each link and updating it every time the time increments. I'm not sure how that would be in terms of efficiency though?

[callumacrae]

Save the time the page was opened to a var on page load, and on unload save it to a cookie (I don't think you can send AJAX requests on unload). Next time the page is loaded, send the cookie.

[Hyde]

callumacrae, on 04 February 2012 - 01:46 PM, said:

Save the time the page was opened to a var on page load, and on unload save it to a cookie (I don't think you can send AJAX requests on unload). Next time the page is loaded, send the cookie.

Ah, see, more efficient.

[Qasim]

when the page loads, you would, in PHP, set a session variable to the current time.

session_start();
$_SESSION['load_time'] = time();

Then, when the other page loads, set another variable to the current time, then subtract the new time with the old time, to get how long they were on that previous page.

$previous_time = $_SESSION['load_time'];
$current_time = time();
$time_elapsed = $current_time - $previous_time;

And time_elapsed variable will now hold the seconds that have passed from the previous page load to the current one.

[Sole_Wolf]

Qasim, on 04 February 2012 - 01:49 PM, said:

when the page loads, you would, in PHP, set a session variable to the current time.

session_start();
$_SESSION['load_time'] = time();

Then, when the other page loads, set another variable to the current time, then subtract the new time with the old time, to get how long they were on that previous page.

$previous_time = $_SESSION['load_time'];
$current_time = time();
$time_elapsed = $current_time - $previous_time;

And time_elapsed variable will now hold the seconds that have passed from the previous page load to the current one.

I was thinking about doing something like this but the only problem is how would I detect if the user closed the page? Also, I want to store this value into a mysql database and since PHP is server side, I can't get the new elapsed time value unless the user were to click the logout button.

[NeilHanlon]

You're gonna want to figure out how to send ajax on unload... or, maybe onBeforeUnload.

[callumacrae]

Qasim, on 04 February 2012 - 01:49 PM, said:

when the page loads, you would, in PHP, set a session variable to the current time.

session_start();
$_SESSION['load_time'] = time();

Then, when the other page loads, set another variable to the current time, then subtract the new time with the old time, to get how long they were on that previous page.

$previous_time = $_SESSION['load_time'];
$current_time = time();
$time_elapsed = $current_time - $previous_time;

And time_elapsed variable will now hold the seconds that have passed from the previous page load to the current one.

It isn't worth starting a session for this.


How to send AJAX on unload: http://stackoverflow...-ajax-on-unload

[Qasim]

callumacrae, on 04 February 2012 - 04:33 PM, said:

It isn't worth starting a session for this.

Could you please explain what you mean by saying that? Store it in an HTML form instead if starting a session is really that much of a problem. I haven't done research on the bad things about sessions so I wouldnt know any better.

[Daniel15]

Google Analytics does exactly this - Tracks how long people are on the site for, and the "bounce rate" (number of people that just hit one page and leave). They do it using JavaScript, so it can't be too hard. Not 100% sure how it does it though. It's not AJAX as you can't do cross-domain AJAX. I think it inserts images with tracking stuff in the querystring.

var image = document.createElement('img');
image.src = 'track.png?closed=true&other=stuff_here';
document.body.appendChild(image);

You may need to call

ignore_user_abort()

in your PHP script, as the connection will be cut off a bit after the request is sent (if you do it onclose)

[callumacrae]

Qasim, on 04 February 2012 - 04:59 PM, said:

Could you please explain what you mean by saying that? Store it in an HTML form instead if starting a session is really that much of a problem. I haven't done research on the bad things about sessions so I wouldnt know any better.

session_start() actually uses a fairly significant amount of resources, and it isn't worth starting a session when there are other, just as easy, solutions that don't require the use of sessions.