cookie tracking

edspace

I have a music website that keeps track of the number of times a visitor clicks on an album or listens to a song.

Every time a user clicks on a song I update the count field in the database. (count++). This works fine but a lot of people took advantage of the unlimited counting to refresh the page as many times as they wanted and this would increase the album's points and make the album go in the top 10.

The only way I could think of stopping the average visitor from abusing the system was by setting a cookie based on the album id. So if someone visits album.php?id=5 I set cookie 'album5' to expire in about 5 minutes. As long as the cookie exists I would not increase the count for album 5. So the average visitor who is unaware of cookies could refresh the page 100 times in 5 minutes but he would only increase the count by 1.

This system works fine but I noticed that the cookies are not expiring in the time that I am telling them to. I have noticed this problem on IE 5 and 6.

This is how I set the cookies.

//if album id is set, set cookie to expire in 5 minutes
if (isset($id) ){
setcookie ("album$id", 1, time()+300 );
}

I have made a test page to print the cookies and they seem to exist for a long time.

Any sugestions on what could be causing this? Is the server time() incorrect?

Any other way to stop the visitors from incrementing the count with every page load?

dalecosp

That's pretty much how most cookies get set. One of my sites does this:

$now=time();
$WarnCookie=$_COOKIE[WarnCookie];

if ($WarnCookie !="set") {
        $expire=$now+3600;
        setcookie("WarnCookie", "set", "$expire");
        $IncludeBrowserAlert="yes";
        }

So it doesn't seem that different...

By way of curiousity, how do you know the cookies aren't expiring? Also, I guess you could try the same strategy with sessions instead of cookies....

edspace

I have made a test.php script that prints cookies.

<?php
print_r($_COOKIE);
?>

I reload this page after x minutes and cookies are still there.

I just tried out netscape 7.0 and everything works fine. The cookies expire in the time they are supposed to.

IE 6.0 is still keeping them longer then it should. If they don't expire in time the average user that visits my site will have a new cookie with almost very click they make. I remember reading somewhere that there is a 20 cookie limit for domain.

By expiring them every couple of minutes I am limiting the number of cookies active and also keeping php resources down.

I could try the same thing with sessions but from I don't think you can set an individual expire time for every session variable. So in a matter of minutes the session will have 20 some variables and this will slow down page processing on an already very busy server.

marque

Sessions are probably cleaner and more effective. The only draw back is the session closes when the user closes their browser. But if you wanted cookies to expire after 5 minutes, it doesn't seem like such a problem

do this

session_start()

if(isset($albumID)) {
session_register(ID_Array)
$ID_Array[] = $albumID;
}

I would put it in an array because you may have one 'prat' user who likes to jump throuh one album to another and if it wern't in an array each albumID would overwrite each other.

marque

In that case try session_cache_expire()

edspace

session_cache_expire() is a universal setting for the entire engine. There are many other php applications on the same server and if i change session_cache_expire() it will change on php.ini. I don't want the entire session to expire. I just want the session variables to expire.

I don't think your code will do the trick. With cookies if a visitor goes to albums 4, 5, and 6 he would have 3 cookies set.

album.php?id = 4
album$id \album4 cookie set

album.php?id = 5
album$id \album5 cookie set

album.php?id = 6
album$id \album6 cookie set

This is all dynamic and it goes on for all the albums that the user visits.

so if the user visits album.php?id=6 for the first time

set cookie album6
if (!isset($_COOKIE['album6'])) //this will be true
counter++ in database for album 6

when he visits or refreshes the page for the second time

set cookie album6
if (!isset($_COOKIE['album6'])) //this will be false
counter++ in database for album 6

This issue is not worth designing a system with sessions or even database tracking. If someone can show me how to get IE to understand cookies like netscape does I will be set.

here are my cookies after listening to a couple of songs.

Array ( [album1] => 1 [song4] => 1 [PHPSESSID] => b3cac8a0d71e9beb4ca30c9bcd04d0b3 [album126] => 1 [song1526] => 1 [song1165] => 1 [song1104] => 1 [song1955] => 1 )

dalecosp

Originally posted by edspace
I could try the same thing with sessions but from I don't think you can set an individual expire time for every session variable. So in a matter of minutes the session will have 20 some variables and this will slow down page processing on an already very busy server.

Well, I don't know why you couldn't. The thing would be the logic itself, and the fact that you'd need to check them on just about every transaction, and that could get quite expensive, as you say. To do it, though, make each Session var an array containing an album ID and a timestamp, then whenever you do any transaction, you iterate the array(s) and unset() any array whose timestamp is older than time() minus 300 seconds, or whatever. As to how busy your server is, only you know. Of course, if you start limiting clicks, you may free up some resources 😉

edspace

After a good night of sleep I opened my test.php page in internet explorer and the cookies were gone. So it takes hours for a cookie in IE to expire.

Like I said this problem is not worth loading the server with huge sessions and a lot of if statements. If I cannot solve this problem I will probably keep track of only the last 2 albums. So if someone wants to vote twice for an album they have to first visit 2 other albums.

-> they visit album 5

alb_history[1] = 5
increment counter

-> they visit album 6

alb_history [2] = 6
increment counter

-> they visit album 5 again
don't increment counter because it exists in alb_history[1]

-> they visit album 7
alb_history[1] = 7
increment counter

-> they visit album 5 again
alb_history[2] = 5
increment counter because history only has 6 and 7 (not 5)

So if the user wants to vote more than once for album 5 they have to visit 2 other albums. The average visitor will not know what I do with sessions and it will take them time before they figure out how i track votes. Even if they do figure it out they will go nuts refreshing pages to increment album ratings.

I am just surprised how this problem has not come up before with other people.

edspace

To solve the problem I now use session tracking rather then cookie tracking.

Basically I registered an array in the session with 20 elements.

$_SESSION['history'] = array();
fill in the first 20 elements.

Every time they visit an album I add an element.
$_SESSION['history'][] = "a$id"

So if i visit album 5 I add an element at the end of the array with value a5.
Now I have 21 elements so I have to delete the first one by using array_shift().

array_shift ($_SESSION['history']);

When they listen to a song I use the same logic but instead of
$SESSION['history'][] = "a$id"
I use
$SESSION['history'][] = "s$id"

I separate albums from songs because the id for an album might be the same as a song id.

Here is the actual code for the album tracking. Hope this helps someone. I don't know how the server will react to the extra values performance wise but I will find out pretty soon.

if (!in_array ("a$id", $_SESSION['history'])){
			$update = mysql_query("UPDATE albums SET alb_hits=(alb_hits + 1) WHERE alb_id='$id'");
			$_SESSION['history'][] = "a$id";
			array_shift ($_SESSION['history']);
		}