How does this forum's search progress page work?

minorgod

I've got a PHP shopping cart that I'd like to modify so the checkout page does the same type of this that this forum's search page does when you submit a search. It gives you a progress page that tells you your search is in progress, then it shows you the results page a moment later. This would be perfect for keeping people from submitting duplicate orders to my onilne store, but I don't have a clue how it is done. Could someone plese give me a brief explanation as to the concepts involved in doing it? I don't need exact instructions, just a general idea of how that interim page works and then refreshes with the results.

Drakla

Have you viewed the source on the interim page - it's basically a meta refresh, this is what I just ripped out of it

<html>
<head><title>PHP Builder Community Forums</title>
<meta http-equiv="Refresh" content="1; URL=search.php?s=&action=showresults&searchid=556357&sortby=&sortorder=">
<meta http-equiv="MSThemeCompatible" content="Yes">

.... etc etc

So basically it just keeps trying to get the results page until that page is ready to appear. I just tested that it doesn't cause multiple gets of the page, too by putting in a counter that's updated in a text file, then a 10 second delay... so it's just a case of a html file like this:

<meta http-equiv="refresh" content="1;URL=waitforit.php">
<html>
<head>
<title>Untitled Document</title>
<meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1">
</head>
<body>
Wait now...
</body>
</html>

and just for the sake of it I did this is waitforit.php

<?php
@$value=file_get_contents('count.txt');

$fp=fopen('count.txt', 'w');

fwrite($fp, ++$value); fclose($fp);

sleep(10);

echo "You've run this $value times";
?>

minorgod

Thanks. That helps quite a bit. I'm curious though, how to make a wait script that knows whether there have been search results returned yet. At some point, results are returned from a database query and the script knows to allow the redirect to happen at that point. Does that sound like what happens? I'm trying to implement this for a shopping cart order page where I want the page to tell the user that his order is being processed, then when the order is finished processing, cause the page to refresh with the order details screen. How would I inject the results back into the https stream or trigger something that would tell the page to redirect to a new location once the results are returned?

Drakla

The wait page will just change when the php page has finished its processing and is ready to fess up data, that's basically what I was 'simulating' with the 10 second pause. I was concerned that as the refresh is set to 1 second it might just continually trigger grabs of the page, but that doesn't happen.

This site passes the search guff through in the url parameters, but you probably won't want to do that. You could just save all your in between data in a session, and the waiting page could refresh to a page that just loads the whole lot back in again.