public function renderString($template, array $params = null)
    {
        if (! empty($params)) {
            $this->assign($params);
        }

        $compiled = $this->getCompiler()->compile($template);

        $tempFile = tempnam(sys_get_temp_dir(), __FUNCTION__);

        $this->writeToFile($tempFile, $compiled);

        $template = $this->readBuffer($tempFile);

        unlink($tempFile);

        return $template;
    }