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");
}