There are a couple of reasons you might want to do server-side presence checks. It lets you avoid having to deal with any library compatibility issues, it improves your page load time by not requiring the users to download the client-side presence API code, and it lets you avoid that little flash of "requires javascript" or "we're offline" before your true presence is displayed. Here's a quick example of how you might go about doing server-side presence in PHP.
Note: Requires PHP ver 5, could be ported to ver 4.
<?php
$doc = new DOMDocument();
$doc->load('https://libraryh3lp.com/presence/jid/{name}/chat.libraryh3lp.com/xml');
$show = 'unavailable';
$resources = $doc->getElementsByTagName('resource');
if ($resources->length > 0) {
$show = $resources->item(0)->getAttribute('show');
}
if ($show == 'available') {
?>You are available for chatting.<?php
} else {
?>You are not available.<?php
}
?>