I have successfully created and loaded a PDF, but I'm not able to access the metadata. Here is my code which I took from the Zend Framework site:
...
$pdf = Zend_Pdf::load()$pdfPath;
$metadata = $pdf->getMetadata();
$metadataDOM = new DOMDocument();
$metadataDOM->loadXML($metadata);

The following error is generated: Warning: DOMDocument::loadXML()[domdocument.loadxml]: Empty string supplied as input...

I can view the PDF along with the XMP document file and information using Acrobat. How can I access the XMP using Zend library components?

Thanks.