--- /dev/null
+<?php
+
+namespace Drupal\system;
+
+use Drupal\Core\Access\AccessResult;
+use Drupal\Core\Entity\EntityAccessControlHandler;
+use Drupal\Core\Entity\EntityInterface;
+use Drupal\Core\Session\AccountInterface;
+
+/**
+ * Defines the access control handler for the date format entity type.
+ *
+ * @see \Drupal\system\Entity\DateFormat
+ */
+class DateFormatAccessControlHandler extends EntityAccessControlHandler {
+
+ /**
+ * {@inheritdoc}
+ */
+ protected function checkAccess(EntityInterface $entity, $operation, AccountInterface $account) {
+ // There are no restrictions on viewing a date format.
+ if ($operation == 'view') {
+ return AccessResult::allowed();
+ }
+ // Locked date formats cannot be updated or deleted.
+ elseif (in_array($operation, ['update', 'delete'])) {
+ if ($entity->isLocked()) {
+ return AccessResult::forbidden()->addCacheableDependency($entity);
+ }
+ else {
+ return parent::checkAccess($entity, $operation, $account)->addCacheableDependency($entity);
+ }
+ }
+
+ return parent::checkAccess($entity, $operation, $account);
+ }
+
+}