EntityAccessControlHandler.php

<?php

namespace Drupal\Core\Entity;

use Drupal\Core\Access\AccessResult;
use Drupal\Core\Field\FieldItemListInterface;
use Drupal\Core\Field\FieldDefinitionInterface;
use Drupal\Core\Language\LanguageInterface;
use Drupal\Core\Session\AccountInterface;

/**
 * Defines a default implementation for entity access control handler.
 */
class EntityAccessControlHandler extends EntityHandlerBase implements EntityAccessControlHandlerInterface {

  /**
   * Stores calculated access check results.
   *
   * @var array
   */
  protected $accessCache = [];

  /**
   * The entity type ID of the access control handler instance.
   *
   * @var string
   */
  protected $entityTypeId;

  /**
   * Information about the entity type.
   *
   * @var \Drupal\Core\Entity\EntityTypeInterface
   */
  protected $entityType;

  /**
   * Allows to grant access to just the labels.
   *
   * By default, the "view label" operation falls back to "view". Set this to
   * TRUE to allow returning different access when just listing entity labels.
   *
   * @var bool
   */
  protected $viewLabelOperation = FALSE;

  /**
   * Constructs an access control handler instance.
   *
   * @param \Drupal\Core\Entity\EntityTypeInterface $entity_type
   *   The entity type definition.
   */
  public function __construct(EntityTypeInterface $entity_type) {
    $this->entityTypeId = $entity_type->id();
    $this->entityType = $entity_type;
  }

  /**
   * {@inheritdoc}
   */
  public function access(EntityInterface $entity, $operation, AccountInterface $account = NULL, $return_as_object = FALSE) {
    $account = $this->prepareUser($account);
    $langcode = $entity->language()->getId();

    if ($operation === 'view label' && $this->viewLabelOperation == FALSE) {
      $operation = 'view';
    }

    if (($return = $this->getCache($entity->uuid(), $operation, $langcode, $account)) !== NULL) {
      // Cache hit, no work necessary.