Example

require_once "XML/RDDL.php";

// create new RDDL parser
$rddl   = &new XML_RDDL();

// parse a document that contains RDDL resources
$result = $rddl->parseRDDL('http://www.rddl.org');
// check for error
if (PEAR::isError($result)) {
echo	sprintf( "ERROR: %s (code %d)", $result->getMessage(), $result->getCode());
exit;
}

// get all resources
$resources = $rddl->getAllResources();
echo	"<pre>";
print_r($resources);
echo	"</pre>";

//	get one resource by its Id
$test = $rddl->getResourceById('CSS');
echo	"<pre>";
print_r($test);
echo	"</pre>";

// get all stylesheets
$test = $rddl->getResourcesByNature('http://www.w3.org/1999/XSL/Transform');
echo	"<pre>";
print_r($test);
echo	"</pre>";

// get all normative references
$test = $rddl->getResourcesByPurpose('http://www.rddl.org/purposes#normative-reference');
echo	"<pre>";
print_r($test);
echo	"</pre>";