ViewsTestDataController.php

<?php

declare (strict_types=1);
namespace Drupal\views_test_data\Controller;

use Drupal\Core\Security\TrustedCallbackInterface;

/**
 * Controller class for views_test_data callbacks.
 */
class ViewsTestDataController implements TrustedCallbackInterface {
  
  /**
   * Renders an error form page.
   *
   * This contains a form that will contain an error and an embedded view with
   * an exposed form.
   */
  public function errorFormPage() {
    $build = [];
    $build['view'] = [
      '#type' => 'view',
      '#name' => 'test_exposed_form_buttons',
    ];
    $build['error_form'] = \Drupal::formBuilder()->getForm('Drupal\\views_test_data\\Form\\ViewsTestDataErrorForm');
    return $build;
  }
  
  /**
   * Render API callback: For testing placeholdering only.
   *
   * This function is assigned as a #lazy_builder callback.
   */
  public static function placeholderLazyBuilder() {
    // No-op.
    return [];
  }
  
  /**
   * Tests pre_render function.
   *
   * @param array $element
   *   A render array.
   *
   * @return array
   *   The changed render array.
   */
  public static function preRender($element) {
    $element['#markup'] = '\\Drupal\\views_test_data\\Controller\\ViewsTestDataController::preRender executed';
    return $element;
  }
  
  /**
   * {@inheritdoc}
   */
  public static function trustedCallbacks() {
    return [
      'placeholderLazyBuilder',
      'preRender',
    ];
  }

}