public static function sendExcel(\PHPExcel_Writer_IWriter $writer, $fileName = NULL)
{
header("Pragma: public");
header("Expires: 0");
header("Cache-Control: must-revalidate, post-check=0, pre-check=0");
header("Content-Type: application/force-download");
header("Content-Type: application/octet-stream");
header("Content-Type: application/download");
header("Content-Disposition: attachment;filename={$fileName}");
header("Content-Transfer-Encoding: binary ");
//Seems that there's a bug on PHP excel 2007 and we can't write directly
//to stdout. Actually the code attempts to make the EXACT same thing
//we are doing here when the string equals to php://stdout or php://output
$file = File::makeTemporary('__apf_excel_download');
$writer->save($file);
$file->chunkedOutput();
}
