kartik\export\ExportMenu::setHttpHeaders PHP Метод

    protected function setHttpHeaders()
    {
        $config = ArrayHelper::getValue($this->exportConfig, $this->_exportType, []);
        $extension = ArrayHelper::getValue($config, 'extension', 'xlsx');
        $mime = ArrayHelper::getValue($config, 'mime', '');
        if (strstr($_SERVER["HTTP_USER_AGENT"], "MSIE") == false) {
            header("Cache-Control: no-cache");
            header("Pragma: no-cache");
        } else {
            header("Cache-Control: must-revalidate, post-check=0, pre-check=0");
            header("Pragma: public");
        }
        header("Expires: Sat, 26 Jul 1979 05:00:00 GMT");
        header("Content-Encoding: {$this->encoding}");
        if (!empty($mime)) {
            header("Content-Type: {$mime}; charset={$this->encoding}");
        }
        header("Content-Disposition: attachment; filename=\"{$this->filename}.{$extension}\"");
        header("Cache-Control: max-age=0");
    }