Contao\CoreBundle\EventListener\StoreRefererListener::storeFrontendReferer PHP Метод

    private function storeFrontendReferer(Request $request)
    {
        $refererOld = $this->session->get('referer');
        if (!$this->canModifyFrontendSession($request, $refererOld)) {
            return;
        }
        $refererNew = ['last' => (string) $refererOld['current'], 'current' => $this->getRelativeRequestUri($request)];
        $this->session->set('referer', $refererNew);
    }