islandora_premis.module

<?php

// phpcs:disable
if (class_exists('\EasyRdf_Graph') && !class_exists('\EasyRdf\Graph')) {
    class_alias('\EasyRdf_Graph', '\EasyRdf\Graph');
}
if (class_exists('\EasyRdf_Namespace') && !class_exists('\EasyRdf\RdfNamespace')) {
    class_alias('\EasyRdf_Namespace', '\EasyRdf\RdfNamespace');
}
// phpcs:enable

use EasyRdf\Graph;
use EasyRdf\RdfNamespace;

/**
 * Implements hook_islandora_premis_turtle_alter().
*/
function islandora_premis_islandora_premis_turtle_alter($nid, &$turtle) {
  $config = \Drupal::config('islandora_premis.settings');
  $node = \Drupal::entityTypeManager()->getStorage('node')->load($nid);
  $utils = \Drupal::service('islandora.utils');
  $media_source = \Drupal::service('islandora.media_source_service');
  $file_uri_lookup = \Drupal::service('islandora_premis.utils');
  $current_path = \Drupal::service('path.current')->getPath();
  if (\Drupal::moduleHandler()->moduleExists('islandora_riprap')) {
    $islandora_riprap_utils = \Drupal::service('islandora_riprap.riprap');
  }

  if (!$node) {
    return array();
  }

  $url = \Drupal\Core\Url::fromRoute('entity.node.canonical', ['node' => $nid], ['absolute' => TRUE])->toString();

  /**
   * @var Symfony\Component\Serializer\Serializer $serializer
   */
  $serializer = \Drupal::service('serializer');
  $jsonld = $serializer->serialize($node, 'jsonld');

  $graph = new Graph($url, $jsonld, 'jsonld');
  $graph->addType($url, "http://www.loc.gov/premis/rdf/v3/IntellectualEntity");

  $media = $utils->getMedia($node);

  if (count($media) > 0) {
    foreach ($media as $medium) {
      $file = $media_source->getSourceFile($medium);
      $file_url = $file_uri_lookup->getUrl($medium->id());
      if (is_null($file_url)) {
        return;
      }

      $binary_resource_url = $file_url;
      if (\Drupal::moduleHandler()->moduleExists('islandora_riprap')) {
        $riprap_config = \Drupal::config('islandora_riprap.settings');
        if ($riprap_config->get('use_drupal_urls')) {
          $binary_resource_url = $islandora_riprap_utils->getLocalUrl($medium->id());
        }
      }

      // Register some namespaces.
      $ns = new RdfNamespace();
      $ns->set('premisObject', 'http://www.loc.gov/premis/rdf/v3/Object');
      $ns->set('premis', 'http://id.loc.gov/vocabulary/preservation/eventOutcome');
      $ns->set('crypHashFunc', 'http://id.loc.gov/vocabulary/preservation/cryptographicHashFunctions/');
      $ns->set('ebucore', 'https://www.ebu.ch/metadata/ontologies/ebucore#');

      $graph->resource($binary_resource_url, 'premisObject:File');
      $graph->add($binary_resource_url, 'premis:size', $file->getSize());
      $graph->add($binary_resource_url, 'premis:compositionLevel', 0);
      $graph->add($binary_resource_url, 'ebucore:hasMimeType', $file->getMimeType());

      $original_name_field = $config->get('islandora_premis_file_original_name_field');
      if ($medium->hasField($original_name_field)) {
        $original_name = trim($medium->get($original_name_field)->getString());
        if (strlen($original_name)) {
          $graph->add($binary_resource_url, 'premis:originalName', $original_name);
        }
      }
    }
  }
  $turtle = $graph->serialise('turtle');


}