private function getSourceXmlDocument()
{
if (($content = $this->getDocumentContent()) !== '') {
$document = new DOMDocument();
$document->loadXML($content);
return $document;
} else {
if (($path = $this->getDocumentPath()) !== '') {
$document = new DOMDocument();
$document->load($path);
return $document;
} else {
return null;
}
}
}