warning page expired

[twocents]

Hi All,
I'm using internet explorer 6.whatever-the-newest is.
When I'm searching a forum and hit my back button, I get: warning page expired

I have to hit refresh to get the data back. It's VERY annoying.
Can anyone tell me how to stop it?

thanks!

[Vernon Frazee]

When you search a forum, the server, (not your computer), has to store a copy of the listing it came up with for you in one or more temporary files on the server. As you move forward through these pages, the one you just viewed is deleted off of the server. (There is a built in timer involved in this process too). If you then click the Back button, the deleted temporary page is no longer on the server. When you then click the Refresh button, the search criteria you originally entered is resent to the server so it can rebuild a new set of temporary files.

One way to get around this, here on VirtualDr anyway, is to keep the listing in one browser window, then right-click the message you want to read and select "Open in a new window". When you're done reading that message, simply close that window and your original listing will still be there, just as you left it.

[Welshjim]

Vernon Frazee--When I'm searching a forum and hit my back button, I get: warning page expired
With that word Search underlined, is your explanation correct? I rarely have a problem with the Back button, but if I have run a Search that error message is what I get, even if I have run the Search in a New Window. I just live with it and assume it is the way the Search function works ("You can't go back again" to paraphrase Thomas Wolfe).

[Nix]

If I do a search and upon the resultant screen of threads hit the back button, it reexecutes the search.

The only time I get the Warning: Page Expired message is after replying to a thread and then after submtting and being taken to the new screen, hitting the back button.

It states the following:

Warning: Page has Expired

The page you requested was created using information you submitted in a form. This page is no longer available. As a security precaution, Internet Explorer does not automatically resubmit your information for you.

To resubmit your information and view this Web page, click the Refresh button.

[Nix]

Are you talking about http://discussions.virtualdr.com/images/top_search.gif (http://discussions.virtualdr.com/search.php?s=)

[kv]

Web pages can be coded with a lifetime, they can set to expire immediately, remain indefinitely or anywhere in between. This setting is generally used for caching, so when you are repeatedly visiting the same pages they are drawn from your stored copy, rather than re-downloading.

The problem is that dynamic websites often use "transparent'" pages that load solely to perform a server-side function and then redirect to the next page, this may happen without you realizing it because all you'll see is a blank page before the next one loads. This often happens in pages that do processing, such as search functions. The authors of the page will set these pages to expire immediately, to prevent you from going back and re-running the particularly operation they just did.

To put it in another light, imagine if you went onto a website and performed an online credit card transaction instead of a search... Once your transaction was through, if you tried to back up you could possibly hit the page that actually processed the transaction and it could be repeated. It's a safeguard more than anything else.

The other reason to force pages to expire immediately, particularly with search functions or pages that have regularly changing data, is to ensure that visitors are always seeing the correct information, instead of a previously viewed page.

In Nix's example, and I've made this mistake before, if you hit the back button after a post and then force a refresh after getting the "page expired" warning, you wind up with a second identical post, you'll notice this happen from time to time in this board....

Anyways, sorry for the long-winded explanation, but page-caching and expiration was a problem for me when I started developing a db-driven web application, so I had to educate myself the hard way. If there's one thing I've since learned, it's that a properly designed website should allow for navigation within the site's pages, without requiring the need for back or forward buttons.

Hope this helps...?

KV