How to hook on paragraph deletion?

Question

I'm on D9 and I've a paragraph inside a content type node.

I need to hook when the paragraph is deleted to do some custom logic and set up a queue.

I've tried hook_entity_delete, hook_entity_predelete or hook_paragraph_delete, hook_paragraph_predelete: those hooks run during cron, if the node containing the paragraph is deleted.

However, it seems to me those aren't triggered if an existing paragraph is deleted via the widget inside the edit form of the node.

Is there a way to intercept that case/solve my problem?

Answer 1

You need to implement a node update hook and compare the paragraph IDs:

use Drupal\node\Entity\NodeInterface;

/**
 * Implements hook_ENTITY_TYPE_update() for node entities.
 */
function mymodule_node_update(NodeInterface $node) {
  if ($node->getType() == 'my_content_type') {
    $ids = array_column($node->field_paragraph->getValue(), 'target_id');
    $original_ids = array_column($node->original->field_paragraph->getValue(), 'target_id');
    // compare IDs
  }
}

If this is a nested paragraph then use hook_paragraph_update() for the parent paragraph type.