public function scriptVariables()
    {
        $data = json_encode([
            'locale' => $this->get('locale'),
            'app_name' => $this->get('app_name'),
            'app_skin' => $this->get('app_skin'),
            'app_theme' => $this->get('app_theme'),
            'app_url' => $this->get('app_url'),
        ]);

        if (JSON_ERROR_NONE !== json_last_error()) {
            throw new \RuntimeException(json_last_error_msg());
        }

        return $data;
    }