/**
* Collects ISBN, LCCN, and OCLC numbers to use in calling preview APIs
*
* @return array
*/
public function getPreviewIds()
{
// Extract identifiers from record driver if it supports appropriate methods:
$isbn = is_callable([$this->driver, 'getCleanISBN']) ? $this->driver->getCleanISBN() : '';
$lccn = is_callable([$this->driver, 'getLCCN']) ? $this->driver->getLCCN() : '';
$oclc = is_callable([$this->driver, 'getOCLC']) ? $this->driver->getOCLC() : [];
// Turn identifiers into class names to communicate with jQuery logic:
$idClasses = [];
if (!empty($isbn)) {
$idClasses[] = 'ISBN' . $isbn;
}
if (!empty($lccn)) {
$idClasses[] = 'LCCN' . $lccn;
}
if (!empty($oclc)) {
foreach ($oclc as $oclcNum) {
if (!empty($oclcNum)) {
$idClasses[] = 'OCLC' . $oclcNum;
}
}
}
return $idClasses;
}