public function render()
{
// Create XML writer
$objWriter = new XMLWriter(XMLWriter::STORAGE_MEMORY);
// XML header
$objWriter->startDocument('1.0', 'UTF-8', 'yes');
// Properties
$objWriter->startElement('Properties');
$objWriter->writeAttribute('xmlns', 'http://schemas.openxmlformats.org/officeDocument/2006/extended-properties');
$objWriter->writeAttribute('xmlns:vt', 'http://schemas.openxmlformats.org/officeDocument/2006/docPropsVTypes');
// Application
$objWriter->writeElement('Application', 'Microsoft Office PowerPoint');
// Slides
$objWriter->writeElement('Slides', $this->getPresentation()->getSlideCount());
// ScaleCrop
$objWriter->writeElement('ScaleCrop', 'false');
// HeadingPairs
$objWriter->startElement('HeadingPairs');
// Vector
$objWriter->startElement('vt:vector');
$objWriter->writeAttribute('size', '4');
$objWriter->writeAttribute('baseType', 'variant');
// Variant
$objWriter->startElement('vt:variant');
$objWriter->writeElement('vt:lpstr', 'Theme');
$objWriter->endElement();
// Variant
$objWriter->startElement('vt:variant');
$objWriter->writeElement('vt:i4', '1');
$objWriter->endElement();
// Variant
$objWriter->startElement('vt:variant');
$objWriter->writeElement('vt:lpstr', 'Slide Titles');
$objWriter->endElement();
// Variant
$objWriter->startElement('vt:variant');
$objWriter->writeElement('vt:i4', '1');
$objWriter->endElement();
$objWriter->endElement();
$objWriter->endElement();
// TitlesOfParts
$objWriter->startElement('TitlesOfParts');
// Vector
$objWriter->startElement('vt:vector');
$objWriter->writeAttribute('size', '1');
$objWriter->writeAttribute('baseType', 'lpstr');
$objWriter->writeElement('vt:lpstr', 'Office Theme');
$objWriter->endElement();
$objWriter->endElement();
// Company
$objWriter->writeElement('Company', $this->getPresentation()->getDocumentProperties()->getCompany());
// LinksUpToDate
$objWriter->writeElement('LinksUpToDate', 'false');
// SharedDoc
$objWriter->writeElement('SharedDoc', 'false');
// HyperlinksChanged
$objWriter->writeElement('HyperlinksChanged', 'false');
// AppVersion
$objWriter->writeElement('AppVersion', '12.0000');
$objWriter->endElement();
$this->oZip->addFromString('docProps/app.xml', $objWriter->getData());
// Return
return $this->oZip;
}