dsfr4drupal-1.x-dev/src/Dsfr4DrupalPreRender.php

<?php

namespace Drupal\dsfr4drupal;

use Drupal\Core\Render\Element;
use Drupal\Core\Security\TrustedCallbackInterface;

/**
 * Implements trusted prerender callbacks for the "DSFR for Drupal" theme.
 *
 * @internal
 */
class Dsfr4DrupalPreRender implements TrustedCallbackInterface {

  /**
   * Prerender callback for Horizontal Tabs element.
   *
   * @param array $element
   *   The render array element.
   *
   * @return array
   *   The new render array element.
   */
  public static function horizontalTabs(array $element): array {
    return self::tabs($element, 'horizontal');
  }

  /**
   * Prerender callback for Vertical Tabs element.
   *
   * @param array $element
   *   The render array element.
   *
   * @return array
   *   The new render array element.
   */
  public static function verticalTabs(array $element): array {
    return self::tabs($element, 'vertical');
  }

  /**
   * Prerender callback for tabs element.
   *
   * @param array $element
   *   The render array element.
   *
   * @param string $orientation
   *   The tab orientation key.
   *
   * @return array
   *   The new render array element.
   */
  private static function tabs(array $element, string $orientation): array {
    $isDetails = isset($element['group']['#type']) && $element['group']['#type'] === 'details';
    $existingGroups = isset($element['group']['#groups']) && is_array($element['group']['#groups']);

    // If the horizontal/vertical tabs have a details group, add attributes to those
    // details elements so they are styled as accordion items and have BEM classes.
    if ($isDetails && $existingGroups) {
      $groupKeys = Element::children($element['group']['#groups'], TRUE);

      $groupKey = implode('][', $element['#parents']);
      // Only check siblings against groups because we are only looking for
      // group elements.
      if (in_array($groupKey, $groupKeys)) {
        $childrenKeys = Element::children($element['group']['#groups'][$groupKey], TRUE);

        foreach ($childrenKeys as $childKey) {
          $type = $element['group']['#groups'][$groupKey][$childKey]['#type'] ?? NULL;
          if ($type === 'details') {
            $element['group']['#groups'][$groupKey][$childKey]['#' . $orientation . '_tab_item'] = TRUE;
          }
        }
      }
    }

    return $element;
  }

  /**
   * {@inheritdoc}
   */
  public static function trustedCallbacks(): array {
    return [
      'horizontalTabs',
      'verticalTabs',
    ];
  }

}