CKEditor5CacheTag.php

<?php

declare (strict_types=1);
namespace Drupal\ckeditor5\EventSubscriber;

use Drupal\Core\Cache\CacheTagsInvalidatorInterface;
use Drupal\Core\Config\ConfigCrudEvent;
use Drupal\Core\Config\ConfigEvents;
use Symfony\Component\EventDispatcher\EventSubscriberInterface;

/**
 * A subscriber invalidating cache tags when the default theme changes.
 *
 * @internal
 *   This class may change at any time. It is not for use outside this module.
 */
class CKEditor5CacheTag implements EventSubscriberInterface {
    
    /**
     * The cache tags invalidator.
     *
     * @var \Drupal\Core\Cache\CacheTagsInvalidatorInterface
     */
    protected $cacheTagsInvalidator;
    
    /**
     * Constructs a CKEditor5CacheTag object.
     *
     * @param \Drupal\Core\Cache\CacheTagsInvalidatorInterface $cache_tags_invalidator
     *   The cache tags invalidator.
     */
    public function __construct(CacheTagsInvalidatorInterface $cache_tags_invalidator) {
        $this->cacheTagsInvalidator = $cache_tags_invalidator;
    }
    
    /**
     * Invalidates cache tags when particular system config objects are saved.
     *
     * @param \Drupal\Core\Config\ConfigCrudEvent $event
     *   The Event to process.
     */
    public function onSave(ConfigCrudEvent $event) {
        $config_name = $event->getConfig()
            ->getName();
        // Ckeditor5-stylesheets settings may change when the default theme changes.
        if ($config_name === 'system.theme' && $event->isChanged('default')) {
            // @see ckeditor5_library_info_alter()
            $this->cacheTagsInvalidator
                ->invalidateTags([
                'library_info',
            ]);
        }
    }
    
    /**
     * {@inheritdoc}
     */
    public static function getSubscribedEvents() : array {
        $events[ConfigEvents::SAVE][] = [
            'onSave',
        ];
        return $events;
    }

}