AJAX with PHP function

Hi,

I'm trying to call a PHP function from a static web page to get the progress of a file download, but it isn't working.

Basically I want the get_progress() PHP function to be called and give me the return value every 2 seconds on the web page, without having to refresh the webpage.

So here is the code at the top of the webpage:

<script type="text/javascript">
var guid = "<?=$guid?>";
var progress_int = "<?=$job_progress?>";

$(document).ready( function() {
setInterval( function() {
var value = parseInt($('#progress_id').text());
if(value < 100)
{
$.ajax({
type: "POST",
url: "/xml/order_status.php?guid="+ guid,
dataType: "xml",
success: function(xml) {
$(xml).find('order').each(function(){
var progress_int = parseInt($(this).attr('job_progress'));
});
}
});
$('#progress_id').html("" + progress_int + "");
}
else
{
$('#progress_paragraph').html('Your files have been successfully prepared.<br>Please see below for your download links.');
}
}, 2000);
});
</script>
<? flush(); ?>

This calls the following page, order_status.php:

<?
session_start();
require_once '../config/definitions.pso';
header('Content-type: text/xml');

$guid = urldecode($_REQUEST['guid']);
if(isset($guid)){
$xml_file = GET_JOB_ADDRESS . $guid;
$job_progress = get_job_progress($xml_file);

} else {

$job_progress = 0;

}
?>
<order job_progress="<?=$job_progress?>" />

Which should return the progress of the job as an interger that is returned and updated every 2 seconds here:

Order status: <?=$job_status?> (<span id="progress_id"><?=$job_progress?></span>% complete)<br />

I'm new to this so please be patient.

Thanks,

Gemma

- put a alert(guid); and alert(progress_int) before $(document).ready and see what you get
- replace short tags '<?' with '<?php'. i would also replace '<?=' with '<?php echo '

best regards

Hi,

I've checked out what's going in on Firebug and the code is sound - it just appears to be caching the XML file so it always returns the same progress.

Any ideas?

Hi,

I've checked out what's going in on Firebug and the code is sound - it just appears to be caching the XML file so it always returns the same progress.

Any ideas?
who cache xml? firefox, a proxy, your server?

in php you can use this:

header("Expires: ".gmdate("D, d M Y H:i:s")."GMT");
header("Cache-Control: no-cache, must-revalidate");
header("Pragma: no-cache");


try to disable cache in firefox, i usualy do this when i write code.

best regards

Also there is a flaw in this piece of code:

$.ajax({
type: "POST",
url: "/xml/order_status.php?guid="+ guid,
dataType: "xml",
success: function(xml) {
$(xml).find('order').each(function(){
var progress_int = parseInt($(this).attr('job_progress'));
});
}
});
$('#progress_id').html("" + progress_int + "");

Due to the asynchronous nature of asynchronous requests the program flow will be
1. Start the request
2. Change the content of the element with id "progress_id" to the undefined variable progress_int
3. Some time later the request finishes and sets progress_int as a (local) variable

instead of what you expected
1. Start the request
2. Request finishes and sets progress_int
3. Change the content of the element with id "progress_id" to the content of progress_int