FieldReuseAccessCheck.php

<?php

namespace Drupal\field_ui\Access;

use Drupal\Core\Access\AccessResult;
use Drupal\Core\Access\AccessResultInterface;
use Drupal\Core\Entity\EntityFieldManagerInterface;
use Drupal\Core\Entity\EntityTypeManagerInterface;
use Drupal\Core\Field\FieldTypePluginManagerInterface;
use Drupal\Core\Routing\Access\AccessInterface;
use Drupal\Core\Routing\RouteMatchInterface;
use Drupal\Core\Session\AccountInterface;
use Drupal\field\FieldStorageConfigInterface;
use Symfony\Component\Routing\Route;

/**
 * Defines an access check for the reuse existing fields form.
 */
class FieldReuseAccessCheck implements AccessInterface {
    
    /**
     * Creates a new FieldReuseAccessCheck.
     *
     * @param \Drupal\Core\Entity\EntityTypeManagerInterface $entityTypeManager
     *   The entity type manager.
     * @param \Drupal\Core\Field\FieldTypePluginManagerInterface $fieldTypePluginManager
     *   The field type plugin manager.
     * @param \Drupal\Core\Entity\EntityFieldManagerInterface $entityFieldManager
     *   The entity field manager.
     */
    public function __construct(EntityTypeManagerInterface $entityTypeManager, FieldTypePluginManagerInterface $fieldTypePluginManager, EntityFieldManagerInterface $entityFieldManager) {
    }
    
    /**
     * Checks access to the reuse existing fields form.
     *
     * @param \Symfony\Component\Routing\Route $route
     *   The route to check against.
     * @param \Drupal\Core\Routing\RouteMatchInterface $route_match
     *   The parametrized route.
     * @param \Drupal\Core\Session\AccountInterface $account
     *   The currently logged in account.
     * @param string|null $bundle
     *   (optional) The bundle. Different entity types can have different names
     *   for their bundle key, so if not specified on the route via a {bundle}
     *   parameter, the access checker determines the appropriate key name, and
     *   gets the value from the corresponding request attribute. For example, for
     *   nodes, the bundle key is "node_type", so the value would be available via
     *   the {node_type} parameter rather than a {bundle} parameter.
     *
     * @return \Drupal\Core\Access\AccessResultInterface
     *   The access result.
     */
    public function access(Route $route, RouteMatchInterface $route_match, AccountInterface $account, ?string $bundle = NULL) : AccessResultInterface {
        $access = AccessResult::neutral();
        if ($entity_type_id = $route->getDefault('entity_type_id')) {
            if (empty($bundle)) {
                $entity_type = $this->entityTypeManager
                    ->getDefinition($entity_type_id);
                $bundle = $route_match->getRawParameter($entity_type->getBundleEntityType());
            }
            $field_types = $this->fieldTypePluginManager
                ->getDefinitions();
            // Allows access if there are any existing fields and the user
            // correct permissions.
            foreach ($this->entityFieldManager
                ->getFieldStorageDefinitions($entity_type_id) as $field_storage) {
                // Do not include fields with
                // - non-configurable field storages,
                // - locked field storages,
                // - field storages that should not be added via user interface,
                // - field storages that already have a field in the bundle.
                $field_type = $field_storage->getType();
                $access->addCacheableDependency($field_storage);
                if ($field_storage instanceof FieldStorageConfigInterface && !$field_storage->isLocked() && empty($field_types[$field_type]['no_ui']) && !in_array($bundle, $field_storage->getBundles(), TRUE)) {
                    $permission = $route->getRequirement('_field_ui_field_reuse_access');
                    $access = $access->orIf(AccessResult::allowedIfHasPermission($account, $permission));
                }
            }
            $access->addCacheableDependency($this->entityFieldManager);
        }
        return $access;
    }

}