TaxonomyTermHierarchyConstraint.php

<?php

namespace Drupal\taxonomy\Plugin\Validation\Constraint;

use Drupal\Core\Entity\Plugin\Validation\Constraint\CompositeConstraintBase;
use Drupal\Core\StringTranslation\TranslatableMarkup;
use Drupal\Core\Validation\Attribute\Constraint;

/**
 * Validation constraint for changing the term hierarchy in pending revisions.
 */
class TaxonomyTermHierarchyConstraint extends CompositeConstraintBase {
  
  /**
   * The default violation message.
   *
   * @var string
   */
  public $message = 'You can only change the hierarchy for the <em>published</em> version of this term.';
  
  /**
   * {@inheritdoc}
   */
  public function coversFields() {
    return [
      'parent',
      'weight',
    ];
  }

}