Provides an wrapper to produce a OAI-PMH endpoint.
To use the OAI-PMH Library it is required to make your own implementation of the \Picturae\OaiPmh\Interfaces\Repository interface
Below is an example implementation needs to be modified to return your data
<?php
namespace My\Repository;
use DateTime;
use OpenSkos2\OaiPmh\Concept as OaiConcept;
use Picturae\OaiPmh\Exception\IdDoesNotExistException;
use Picturae\OaiPmh\Implementation\MetadataFormatType as ImplementationMetadataFormatType;
use Picturae\OaiPmh\Implementation\RecordList as OaiRecordList;
use Picturae\OaiPmh\Implementation\Repository\Identity as ImplementationIdentity;
use Picturae\OaiPmh\Implementation\Set;
use Picturae\OaiPmh\Implementation\SetList;
use Picturae\OaiPmh\Interfaces\MetadataFormatType;
use Picturae\OaiPmh\Interfaces\Record;
use Picturae\OaiPmh\Interfaces\RecordList;
use Picturae\OaiPmh\Interfaces\Repository as InterfaceRepository;
use Picturae\OaiPmh\Interfaces\Repository\Identity;
use Picturae\OaiPmh\Interfaces\SetList as InterfaceSetList;
class Repository implements InterfaceRepository
{
/**
* @return string the base URL of the repository
*/
public function getBaseUrl()
{
return 'http://my-data-provider/oai-pmh';
}
/**
* @return Identity
*/
public function identify()
{
return new ImplementationIdentity();
}
/**
* @return InterfaceSetList
*/
public function listSets()
{
$items = [];
$items[] = new Set('my:spec', 'Title of spec');
return new SetList($items);
}
/**
* @param string $token
* @return InterfaceSetList
*/
public function listSetsByToken($token)
{
$params = $this->decodeResumptionToken($token);
return $this->listSets();
}
/**
* @param string $metadataFormat
* @param string $identifier
* @return Record
*/
public function getRecord($metadataFormat, $identifier)
{
// Fetch record
$record = $this->getSomeRecord($identifier);
// Throw exception if it does not exists
if (!record) {
throw new IdDoesNotExistException('No matching identifier ' . $identifier, $exc->getCode(), $exc);
}
return new Record($record);
}
/**
* @param string $metadataFormat metadata format of the records to be fetch or null if only headers are fetched
* (listIdentifiers)
* @param DateTime $from
* @param DateTime $until
* @param string $set name of the set containing this record
* @return RecordList
*/
public function listRecords($metadataFormat = null, DateTime $from = null, DateTime $until = null, $set = null)
{
$items = [];
$items[] = new OaiConcept($concept);
// Show token only if more records exists then are shown
$token = $this->encodeResumptionToken($this->limit, $from, $until, $metadataFormat, $set);
return new OaiRecordList($items, $token);
}
/**
* @param string $token
* @return RecordList
*/
public function listRecordsByToken($token)
{
$params = $this->decodeResumptionToken($token);
$records = $this->GetRecords($params);
// Only show if there are more records available else $token = null;
$token = $this->encodeResumptionToken(
$params['offset'] + 100,
$params['from'],
$params['until'],
$params['metadataPrefix'],
$params['set']
);
return new OaiRecordList($items, $token);
}
/**
* @param string $identifier
* @return MetadataFormatType[]
*/
public function listMetadataFormats($identifier = null)
{
$formats = [];
$formats[] = new ImplementationMetadataFormatType(
'oai_dc',
'http://www.openarchives.org/OAI/2.0/oai_dc.xsd',
'http://www.openarchives.org/OAI/2.0/oai_dc/'
);
$formats[] = new ImplementationMetadataFormatType(
'oai_rdf',
'http://www.openarchives.org/OAI/2.0/rdf.xsd',
'http://www.w3.org/2004/02/skos/core#'
);
return $formats;
}
/**
* Decode resumption token
* possible properties are:
*
* ->offset
* ->metadataPrefix
* ->set
* ->from (timestamp)
* ->until (timestamp)
*
* @param string $token
* @return array
*/
private function decodeResumptionToken($token)
{
$params = (array) json_decode(base64_decode($token));
if (!empty($params['from'])) {
$params['from'] = new \DateTime('@' . $params['from']);
}
if (!empty($params['until'])) {
$params['until'] = new \DateTime('@' . $params['until']);
}
return $params;
}
/**
* Get resumption token
*
* @param int $offset
* @param DateTime $from
* @param DateTime $util
* @param string $metadataPrefix
* @param string $set
* @return string
*/
private function encodeResumptionToken(
$offset = 0,
DateTime $from = null,
DateTime $util = null,
$metadataPrefix = null,
$set = null
) {
$params = [];
$params['offset'] = $offset;
$params['metadataPrefix'] = $metadataPrefix;
$params['set'] = $set;
$params['from'] = null;
$params['until'] = null;
if ($from) {
$params['from'] = $from->getTimestamp();
}
if ($util) {
$params['until'] = $util->getTimestamp();
}
return base64_encode(json_encode($params));
}
/**
* Get earliest modified timestamp
*
* @return DateTime
*/
private function getEarliestDateStamp()
{
// Fetch earliest timestamp
return new DateTime();
}
}To create a request and send a response you will need something that can create a PSR 7 server request and emit a PSR 7 response
In this example we use zend-diactoros
composer require zendframework/zend-diactoros
// Where $repository is an instance of \Picturae\OaiPmh\Interfaces\Repository
$repository = new \Your\Implementation\Repository();
$provider = new \Picturae\OaiPmh\Provider($repository);
$request = Zend\Diactoros\ServerRequestFactory::fromGlobals();
$provider = new Picturae\OaiPmh\Provider($repository, $request);
$response = $provider->getResponse();
// Send PSR 7 Response
(new Zend\Diactoros\Response\SapiEmitter())->emit($response);Values for setSpec must be validated yourself before adding them to the header
$header = new \Picturae\OaiPmh\Validator\SetSpecValidator();
$boolean = $header->isValid($value);