Setup OAI-PMH provider endpoint.

app/Http/Controllers/OaiPmhController.php

@@ -0,0 +1,20 @@
+<?php
+
+namespace App\Http\Controllers;
+
+use Psr\Http\Message\ServerRequestInterface;
+
+use App\Repositories\Product;
+
+class OaiPmhController extends Controller
+{
+    public function index(ServerRequestInterface $request)
+    {
+        $repository = new Product();
+        // $provider = new \Picturae\OaiPmh\Provider($repository);
+        $provider = new \Picturae\OaiPmh\Provider($repository, $request);
+        $response = $provider->getResponse();
+
+        return $response;
+    }
+}

app/Repositories/Product.php

@@ -0,0 +1,223 @@
+<?php
+
+namespace App\Repositories;
+
+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 OaiRepository;
+use Picturae\OaiPmh\Interfaces\Repository\Identity;
+use Picturae\OaiPmh\Interfaces\SetList as InterfaceSetList;
+
+class Product implements OaiRepository
+{
+    /**
+     * @return string the base URL of the repository
+     */
+    public function getBaseUrl()
+    {
+        // return 'http://my-data-provider/oai-pmh';
+        return route('api.oai-pmh');
+    }
+
+    /**
+     * @return string
+     * the finest harvesting granularity supported by the repository. The legitimate values are
+     * YYYY-MM-DD and YYYY-MM-DDThh:mm:ssZ with meanings as defined in ISO8601.
+     */
+    public function getGranularity()
+    {
+        return 'YYYY-MM-DD';
+    }
+
+    /**
+     * @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();
+    }
+}

composer.json

@@ -26,9 +26,13 @@
     "league/flysystem": "^1.0",
     "league/flysystem-memory": "^1.0",
     "nothingworks/blade-svg": "^0.3",
+    "nyholm/psr7": "^1.2",
     "orangehill/iseed": "^2.6",
+    "picturae/oai-pmh": "^0.5.20",
     "seld/signal-handler": "^1.1",
-    "spatie/laravel-image-optimizer": "^1.3"
+    "spatie/laravel-image-optimizer": "^1.3",
+    "symfony/psr-http-message-bridge": "~1.0",
+    "zendframework/zend-diactoros": "^2.2"
   },
   "require-dev": {
     "barryvdh/laravel-debugbar": "^3.1",