class TempstoreAccess

class TempstoreAccess implements CoreAccessInterface {
    
    /**
     * The shared tempstore factory.
     *
     * @var \Drupal\Core\TempStore\SharedTempStoreFactory
     */
    protected $tempstore;
    
    /**
     * Constructor for access to shared tempstore.
     */
    public function __construct(SharedTempStoreFactory $tempstore) {
        $this->tempstore = $tempstore;
    }
    
    /**
     * Retreive the tempstore factory.
     */
    protected function getTempstore() {
        return $this->tempstore;
    }
    
    /**
     * Access method to find if user has access to a particular tempstore.
     *
     * @param \Symfony\Component\Routing\Route $route
     * @param \Drupal\Core\Routing\RouteMatchInterface $match
     * @param \Drupal\Core\Session\AccountInterface $account
     *
     * @return \Drupal\Core\Access\AccessResultAllowed|\Drupal\Core\Access\AccessResultForbidden
     */
    public function access(Route $route, RouteMatchInterface $match, AccountInterface $account) {
        $tempstore_id = $match->getParameter('tempstore_id') ? $match->getParameter('tempstore_id') : $route->getDefault('tempstore_id');
        $id = $match->getParameter($route->getRequirement('_ctools_access'));
        if ($tempstore_id && $id) {
            $cached_values = $this->getTempstore()
                ->get($tempstore_id)
                ->get($id);
            if (!empty($cached_values['access']) && $cached_values['access'] instanceof CToolsAccessInterface) {
                $access = $cached_values['access']->access($account);
            }
            else {
                $access = AccessResult::allowed();
            }
        }
        else {
            $access = AccessResult::forbidden();
        }
        // The different wizards will have different tempstore ids and adding this
        // cache context allows us to nuance the access per wizard.
        $access->addCacheContexts([
            'url.query_args:tempstore_id',
        ]);
        return $access;
    }

}