/**
* @param Publication $publication
*
* @return DOMElement
*/
private function createRecordHeader(Publication $publication)
{
$xml = new DOMDocument('1.0', 'UTF-8');
$header = $xml->createElement('header');
$header->appendChild($xml->createElement('identifier', 'oai:' . $this->repositoryIdentifier . ':' . $publication->getId()));
$header->appendChild($xml->createElement('datestamp', $publication->getDateAdded('Y-m-d')));
$keywords = $publication->getKeywords();
foreach ($keywords as $keyword) {
$setSpec = str_replace(' ', '_', $keyword->getName());
$setSpec = strtolower($setSpec);
$header->appendChild($xml->createElement('setSpec', $setSpec));
}
return $header;
}