AllowToolbarPath.php

<?php

namespace Drupal\toolbar\PageCache;

use Drupal\Core\PageCache\RequestPolicyInterface;
use Symfony\Component\HttpFoundation\Request;

/**
 * Cache policy for the toolbar page cache service.
 *
 * This policy allows caching of requests directed to /toolbar/subtrees/{hash}
 * even for authenticated users.
 */
class AllowToolbarPath implements RequestPolicyInterface {
    
    /**
     * {@inheritdoc}
     */
    public function check(Request $request) {
        // Note that this regular expression matches the end of pathinfo in order to
        // support multilingual sites using path prefixes.
        if (preg_match('#/toolbar/subtrees/[^/]+(/[^/]+)?$#', $request->getPathInfo())) {
            return static::ALLOW;
        }
    }

}