OliveroPreRender.php

<?php

namespace Drupal\olivero;

use Drupal\Core\Security\TrustedCallbackInterface;

/**
 * Implements trusted prerender callbacks for the Olivero theme.
 *
 * @internal
 */
class OliveroPreRender implements TrustedCallbackInterface {
    
    /**
     * Prerender callback for text_format elements.
     */
    public static function textFormat($element) {
        $element['format']['#attributes']['class'][] = 'filter-wrapper';
        $element['format']['format']['#wrapper_attributes']['class'][] = 'form-item--editor-format';
        $element['format']['format']['#attributes']['class'][] = 'filter-list';
        $element['format']['format']['#attributes']['class'][] = 'form-element--small';
        $element['format']['format']['#attributes']['class'][] = 'form-element--editor-format';
        $element['format']['guidelines']['#attributes']['class'][] = 'filter-guidelines';
        $element['format']['help']['#attributes']['class'][] = 'filter-help';
        return $element;
    }
    
    /**
     * Prerender callback for status_messages placeholder.
     *
     * @param array $element
     *   A renderable array.
     *
     * @return array
     *   The updated renderable array containing the placeholder.
     */
    public static function messagePlaceholder(array $element) {
        if (isset($element['fallback']['#markup'])) {
            $element['fallback']['#markup'] = '<div data-drupal-messages-fallback class="hidden messages-list"></div>';
        }
        return $element;
    }
    
    /**
     * {@inheritdoc}
     */
    public static function trustedCallbacks() {
        return [
            'textFormat',
            'messagePlaceholder',
        ];
    }

}