/**
* Appends the record's header to the XML response.
*
* Adds the identifier, datestamp and setSpec to a header element, and
* appends in to the document.
*
* @param DOMElement $parentElement
*/
public function appendHeader($parentElement)
{
$headerData['identifier'] = OaiPmhRepository_OaiIdentifier::itemToOaiId($this->item->id);
$headerData['datestamp'] = OaiPmhRepository_Date::dbToUtc($this->item->modified);
$collectionId = $this->item->collection_id;
if ($collectionId) {
$headerData['setSpec'] = $collectionId;
}
$this->createElementWithChildren($parentElement, 'header', $headerData);
}
/**
* Responds to the two main List verbs, includes resumption and limiting.
*
* @param string $verb OAI-PMH verb for the request
* @param string $metadataPrefix Metadata prefix
* @param int $cursor Offset in response to begin output at
* @param mixed $set Optional set argument
* @param string $from Optional from date argument
* @param string $until Optional until date argument
* @uses createResumptionToken()
*/
private function listResponse($verb, $metadataPrefix, $cursor, $set, $from, $until)
{
$listLimit = $this->_listLimit;
$itemTable = get_db()->getTable('Item');
$select = $itemTable->getSelect();
$alias = $itemTable->getTableAlias();
$itemTable->filterByPublic($select, true);
if ($set) {
$itemTable->filterByCollection($select, $set);
}
if ($from) {
$select->where("{$alias}.modified >= ? OR {$alias}.added >= ?", $from);
$select->group("{$alias}.id");
}
if ($until) {
$select->where("{$alias}.modified <= ? OR {$alias}.added <= ?", $until);
$select->group("{$alias}.id");
}
// Total number of rows that would be returned
$rows = $select->query()->rowCount();
// This limit call will form the basis of the flow control
$select->limit($listLimit, $cursor);
$items = $itemTable->fetchObjects($select);
if (count($items) == 0) {
$this->throwError(self::OAI_ERR_NO_RECORDS_MATCH, 'No records match the given criteria');
} else {
if ($verb == 'ListIdentifiers') {
$method = 'appendHeader';
} else {
if ($verb == 'ListRecords') {
$method = 'appendRecord';
}
}
$verbElement = $this->document->createElement($verb);
$this->document->documentElement->appendChild($verbElement);
foreach ($items as $item) {
$record = new $this->metadataFormats[$metadataPrefix]($item, $this->document);
$record->{$method}($verbElement);
// Drop Item from memory explicitly
release_object($this->item);
}
if ($rows > $cursor + $listLimit) {
$token = $this->createResumptionToken($verb, $metadataPrefix, $cursor + $listLimit, $set, $from, $until);
$tokenElement = $this->document->createElement('resumptionToken', $token->id);
$tokenElement->setAttribute('expirationDate', OaiPmhRepository_Date::dbToUtc($token->expiration));
$tokenElement->setAttribute('completeListSize', $rows);
$tokenElement->setAttribute('cursor', $cursor);
$verbElement->appendChild($tokenElement);
} else {
if ($cursor != 0) {
$tokenElement = $this->document->createElement('resumptionToken');
$verbElement->appendChild($tokenElement);
}
}
}
}
/**
* Helper to get the earlieast datestamp of the repository.
*
* @return string OAI-PMH date stamp.
*/
private function _getEarliestDatestamp()
{
$earliestItem = get_record('Item', array('public' => 1, 'sort_field' => 'added', 'sort_dir' => 'a'));
return $earliestItem ? OaiPmhRepository_Date::dbToUtc($earliestItem->added) : OaiPmhRepository_Date::unixToUtc(0);
}