sessions and cache issue

[jamesbond]

To enable the use of the back button in combination with sessions, I added the following line to the top of my pages:

ini_set("session.cache_limiter","public");

This works well, but now I have the problem that when someone clicks on a link they see the 'old' cached page which doesn't reflect the latest changes.

What I would like is the following:

-When people use the back button they should see the cached page

-When they click on a link they should see the "non-cached" page which reflects the latest changes.

How can I accomplish this?

[Theiggsta]

You need to send a no-cache header, here is a sample of one.

  header("Expires: Mon, 14 Jul 1996 05:00:00 GMT"); 
  header("Last-Modified: " . gmdate("D, d M Y H:i:s") . "GMT");
  header("Cache-Control: no-cache, must-revalidate");   
  header("Pragma: no-cache"); 

This basically tells the browser to dump the page because its too old and make a new one from scratch.

I hope that helps.

[jamesbond]

If I don't cache the page then the back button won't work, so the nocache headers would not help here.

When I use sessions my pages are not cached by default.
That's why i used : ini_set("session.cache_limiter","public");

Now the pages are being cached and the back and forward button works, but I need the browser to show the 'newest' pages instead of the cached ones.

How can I enable the use of the back and forward buttons in combination with sessions and have the browser display the most recent changes when people click on a link?

I hope I'm clear enough

[freddydoesphp]

You can trick the browser into not caching the links when people click on them by tacking on a unix timestamp on the end of the link, this way the browser thinks its a new page and you will fool the cache into thinking that way too.

<a href="somelink.php?somevar=someval&ck=<?=time()?>">go there</a>

I use ck it stands for cache killer, but you can use whatever as long as it doesn't conflict with some other var you may be using. I hope that helps.

[Theiggsta]

freddy is right, you could try that.

my version was only to have ti clean out the cache to fetch a page, but it does eat the users bandwith trying to reload every page.

[jamesbond]

I tried Freddy's suggestion and it works!

Freddy and Theiggsta, thank you for your help!