added fallback

src/Plugin/Action/CreatePdfDerivative.php

@@ -18,8 +18,7 @@ use Drupal\Core\Entity\EntityTypeManagerInterface;
 use Drupal\Core\File\FileSystemInterface;
 use Drupal\media\Entity\Media;
 use Drupal\Core\Session\AccountProxyInterface;
-
-
+use Drupal\media\Entity\MediaType;
 
 /**
  * Provides a Create PDF Derivative action.
@@ -116,14 +115,27 @@ final class CreatePdfDerivative extends ConfigurableActionBase implements Contai
    */
   public function execute(ContentEntityInterface $entity = NULL): void {
     $identifier = $this->configuration['media_use_identifier'];
-    $service_term = $this->islandoraUtils->getTermForUri('http://pcdm.org/use#ServiceFile');
     $pdf_term = $this->islandoraUtils->getTermForUri($identifier);
-    $media = $this->islandoraUtils->getMediaWithTerm($entity, $service_term);
+    $terms = [
+      $this->islandoraUtils->getTermForUri('http://pcdm.org/use#ServiceFile'),
+      $this->islandoraUtils->getTermForUri('http://pcdm.org/use#OriginalFile'),
+    ];
+    foreach ($terms as $term) {
+      $media = $this->islandoraUtils->getMediaWithTerm($entity, $term);
+      if ($media) {
+        break;
+      }
+    }
+    if (!$media) {
+      return;
+    }
+
     // Original file info.
-    $field_name = 'field_media_image';
-    $source_file = $media->get($field_name)->entity;
-    $source_uri = $source_file->getFileUri();                // e.g. public://foo/bar.jpg
-    $source_real = $this->fileSystem->realpath($source_uri); // real path exists
+    $bundle = $media->bundle();                 // string, e.g. 'image' or 'file'
+    $media_type = MediaType::load($bundle);
+    $field_name = $media->getSource()->getSourceFieldDefinition($media_type)->getName();    $source_file = $media->get($field_name)->entity;
+    $source_uri = $source_file->getFileUri();
+    $source_real = $this->fileSystem->realpath($source_uri);
 
     // Derive PDF names/paths.
     $pdf_uri = preg_replace('/\.\w+$/', '.pdf', $source_uri);     // public://foo/bar.pdf
@@ -131,7 +143,7 @@ final class CreatePdfDerivative extends ConfigurableActionBase implements Contai
 
     // Run ImageMagick. Prefer absolute path if you know it; leaving as "magick" here.
     $cmd = sprintf(
-      'magick %s %s 2>&1',
+      'convert %s %s 2>&1',
       escapeshellarg($source_real),
       escapeshellarg($pdf_real),
     );