/**
* convert dom to simpleXML
* @param DOMElement $dom
* @param $class cast to child class of SimpleXMLElement
* @return SimpleXMLElement
*/
public static function whole_dom_to_simplexml($dom, $class = 'SimpleXMLElement')
{
if ($dom instanceof DOMElement) {
$save_xml = $dom->ownerDocument->saveXML();
} elseif ($dom instanceof DOMDocument) {
$save_xml = $dom->saveXML();
}
return simplexml_load_string($save_xml, $class, LIBXML_NOCDATA | LIBXML_NOERROR);
}