depcalc-8.x-1.x-dev/tests/modules/depcalc_test/src/EventSubscriber/CalculateHash/SkipHashCalculation.php

<?php

namespace Drupal\depcalc_test\EventSubscriber\CalculateHash;

use Drupal\depcalc\DependencyCalculatorEvents;
use Drupal\depcalc\Event\CalculateHashEvent;
use Drupal\node\NodeInterface;
use Drupal\user\RoleInterface;
use Symfony\Component\EventDispatcher\EventSubscriberInterface;

/**
 * Skip HashCalculation for fields under certain scenario.
 *
 * This is an example event subscriber which depicts, how
 * particular fields from an entity can be skipped from
 * hash calculation.
 */
class SkipHashCalculation implements EventSubscriberInterface {

  /**
   * {@inheritdoc}
   */
  public static function getSubscribedEvents(): array {
    $events[DependencyCalculatorEvents::HASH_CALCULATION][] =
        ['onHashCalculation', 100];
    return $events;
  }

  /**
   * Removes fields of entity from hash calculation.
   *
   * @param \Drupal\depcalc\Event\CalculateHashEvent $event
   *   Hash calculation event.
   */
  public function onHashCalculation(CalculateHashEvent $event): void {
    // Removes label field of 'authenticated' user role from hash calculation.
    if ($event->getEntity() instanceof RoleInterface && $event->getEntity()->id() === 'authenticated') {
      $fields = $event->getHashSource();
      unset($fields['label']);
      $event->setHashSource($fields);
      $event->stopPropagation();
    }
    // Removes title field of node entity from hash calculation.
    if ($event->getEntity() instanceof NodeInterface) {
      $fields = $event->getHashSource();
      unset($fields['title']);
      $event->setHashSource($fields);
      $event->stopPropagation();
    }
  }

}