How to stop jpgraph (gd library) from caching or to force a refresh

[uncleronin]

I'm using a bunch of graphs all over my site to display various statistics. Some pages have lots, some have one. The big issue is that if I display the graphs for a particular page multiple times in a row (changing the parameters each time) the graphs don't refresh. Instead the same graphs are shown each time!

 

Is this because of caching or some php setting or some apache setting (using apache2 btw)? Is there any way to get around this or to force the graphs to refresh?

[chrisuk]

I have noticed the same issue.

 

Perhaps use javascript to force a page refresh after it loads?

[uncleronin]

Refreshing the page doesn't help. I've even gone so far as to prevent the actual page from caching but that doesn't do much either. Then again, images cache differently to pages. In IE the graphs refresh nicely but in FF the caching is handled differently so they dont refresh. I dunno, maybe FF has a cache setting somewhere but I have no idea how to force it to refresh pages. Maybe there's something in PHP which does this?

[o3d]

Maybe try this in your script:

 

<?php

header("Cache-Control: no-cache, must-revalidate"); // HTTP/1.1

header("Expires: Mon, 26 Jul 1997 05:00:00 GMT"); // Date in the past

?>

 

taken from www.php.net

 

[uncleronin]

I've tried using no-cache but not with must-revalidate. Will see what happens.