PHP: session_cache_expire

Description

int session_cache_expire ( [int new_cache_expire] )

session_cache_expire() returns the current setting of session.cache_expire. The value returned should be read in minutes, defaults to 180. If new_cache_expire is given, the current cache expire is replaced with new_cache_expire.

The cache expire is reset to the default value of 180 stored in session.cache_limiter at request startup time. Thus, you need to call session_cache_expire() for every request (and before session_start() is called).

Example 1. session_cache_expire() example


<?php



/* set the cache limiter to 'private' */



session_cache_limiter('private');

$cache_limiter = session_cache_limiter();



/* set the cache expire to 30 minutes */

session_cache_expire(30);

$cache_expire = session_cache_expire();



/* start the session */



session_start();



echo "The cache limiter is now set to $cache_limiter<br />";

echo "The cached session pages expire after $cache_expire minutes";

?>

Note: Setting new_cache_expire is of value only, if session.cache_limiter is set to a value different from nocache.

See also the configuration settings session.cache_expire, session.cache_limiter and session_cache_limiter().

User Contributed Notes
session_cache_expire

bermi·ferrer·[·at·]·akelos·[NO·SPAM]·com
03-Jun-2004 03:11


Hello,

Some of my customers asked me for a solution form their session not to expire when filling large forms. Sometimes it takes them more than 2 hours to submit (phone, desk customers...). 

I know I could have forced an ilayer to be refreshed dynamically and then include PHP code using session_cache_expire() function, but this refreshing a page changes the form focus. So I found this the only solution for them not to loose focus over their form element.



You can make a session not to expire by using this code.

Its a mixture of PHP and JavaScript and can be used on the same page were your code goes or it can be called using an ilayer/iframe from your page. 



I know this is not the best practice, but in some cases were user has no control over server globals and security is not important this can help.



Here is the code.



<?



//First of all we prevent browsers from caching the image

header("Cache-Control: no-store, no-cache, must-revalidate");

header("Cache-Control: post-check=0, pre-check=0", false);

header("Pragma: no-cache");

header("Expires: Mon, 26 Jul 1997 05:00:00 GMT");

header("Last-Modified: " . gmdate("D, d M Y H:i:s") . " GMT"); 



//This piece of code returns a blank gif

if($_GET[img] > 0){ 

    header('Content-Type: image/gif');

    header("Content-Disposition: inline; filename=".time().".gif");

    echo base64_decode(str_replace("\n","","

R0lGODlhAQABAPcAAAAAAAAAQAAAgAAA/

wAgAAAgQAAggAAg/wBAAABAQABAgABA/

wBgAABgQABggABg/wCAAACAQACAgACA/

wCgAACgQACggACg/wDAAADAQADAgADA/

wD/AAD/QAD/gAD//yAAACAAQCAAgCAA/

yAgACAgQCAggCAg/yBAACBAQCBAgCBA/

yBgACBgQCBggCBg/yCAACCAQCCAgCCA/

yCgACCgQCCggCCg/yDAACDAQCDAgCDA/

yD/ACD/QCD/gCD//0AAAEAAQEAAgEAA/

0AgAEAgQEAggEAg/0BAAEBAQEBAgEBA/

0BgAEBgQEBggEBg/0CAAECAQECAgECA/

0CgAECgQECggECg/0DAAEDAQEDAgEDA/

0D/AED/QED/gED//2AAAGAAQGAAgGAA/

2AgAGAgQGAggGAg/2BAAGBAQGBAgGBA/

2BgAGBgQGBggGBg/2CAAGCAQGCAgGCA/

2CgAGCgQGCggGCg/2DAAGDAQGDAgGDA/

2D/AGD/QGD/gGD//4AAAIAAQIAAgIAA/

4AgAIAgQIAggIAg/4BAAIBAQIBAgIBA/

4BgAIBgQIBggIBg/4CAAICAQICAgICA/

4CgAICgQICggICg/4DAAIDAQIDAgIDA/

4D/AID/QID/gID//6AAAKAAQKAAgKAA/

6AgAKAgQKAggKAg/6BAAKBAQKBAgKBA/

6BgAKBgQKBggKBg/6CAAKCAQKCAgKCA/

6CgAKCgQKCggKCg/6DAAKDAQKDAgKDA/

6D/AKD/QKD/gKD//8AAAMAAQMAAgMAA/

8AgAMAgQMAggMAg/8BAAMBAQMBAgMBA/

8BgAMBgQMBggMBg/8CAAMCAQMCAgMCA/

8CgAMCgQMCggMCg/8DAAMDAQMDAgMDA/

8D/AMD/QMD/gMD///8AAP8AQP8AgP8A/

/8gAP8gQP8ggP8g//9AAP9AQP9AgP9A/

/9gAP9gQP9ggP9g//+AAP+AQP+AgP+A/

/+gAP+gQP+ggP+g///AAP/AQP/AgP/A/

///AP//QP//gP///yH5BAEAAP8ALAAAA

AABAAEAAAgEAP8FBAA7"));

    exit;

}



?>



<!-- HERE YOU CAN INSERT THE HTML OR PHP CODE -->



<img name="keepUpdated" src="<?=$_SELF?>?img=999">

<script language="Javascript">

<!--

var updateEvery = 30;//Seconds

function keepUpdated() {

    timer=setTimeout("updateImage()",1000*updateEvery)

}

function updateImage() {

    var randNum = Math.floor(Math.random()*999);

    document.images.keepUpdated.src ="<?=$_SELF?>?img="+randNum;

    keepUpdated();

}

keepUpdated();

//-->

</script>



I hope this can be helpful for someone.



Bermi Ferrer