added linkage hooks

caption_linker.module

@@ -2,5 +2,41 @@
 
 /**
  * @file
- * Primary module hooks for Caption Linker module.
  */
+
+use Drupal\Core\Entity\EntityInterface;
+use Drupal\media\MediaInterface;
+use Drupal\node\NodeInterface;
+
+/**
+ * Implements hook_entity_insert().
+ */
+function caption_linker_entity_insert(EntityInterface $entity): void {
+  if ($entity instanceof MediaInterface) {
+    _caption_linker_link_caption_if_possible($entity);
+  }
+}
+
+/**
+ * Implements hook_entity_update().
+ */
+function caption_linker_entity_update(EntityInterface $entity): void {
+  if ($entity instanceof MediaInterface) {
+    _caption_linker_link_caption_if_possible($entity);
+  }
+}
+
+/**
+ * Tries to link a caption if applicable.
+ */
+function _caption_linker_link_caption_if_possible(MediaInterface $media): void {
+  /** @var \Drupal\islandora\IslandoraUtils $islandora_utils */
+  $islandora_utils = \Drupal::service('islandora.utils');
+  /** @var \Drupal\caption_linker\Service\CaptionLinker $caption_linker */
+  $caption_linker = \Drupal::service('caption_linker.caption_linker');
+
+  $node = $islandora_utils->getParentNode($media);
+  if ($node instanceof NodeInterface) {
+    $caption_linker->linkCaption($node);
+  }
+}