PHPExcel generating totally jacked up output - php

Question

Greetings,
I am having trouble figuring out how to properly use PHP in general and PHPExcel in particular. I have read multiple posts on this topic and yet I've been running around in circles. Here is the relevant portion of my jacked up code:
$viewinv = mysql_connect($sqlsrv,$username,$password);
if (!$viewinv) { die('Could not connect to SQL server. Contact administrator.'); }
mysql_select_db($database, $viewinv) or die('Could not connect to database. Contact administrator.');
$query = "select unit_id,config,location from inventory;";
$result = mysql_query($query);
if ($result = mysql_query($query) or die(mysql_error())) {
$objPHPExcel = new PHPExcel();
$objPHPExcel->getActiveSheet()->setTitle('blah');
$rowNumber = 1;
$headings = array('Unit ID','Config','Location');
$objPHPExcel->getActiveSheet()->fromArray(array($headings),NULL,'A'.$rowNumber);
$rowNumber++;
while ($row = mysql_fetch_row($result)) {
$col = 'A';
foreach($row as $cell) {
$objPHPExcel->getActiveSheet()->setCellValue($col.$rowNumber,$cell);
$col++;
}
$rowNumber++;
}
$objWriter = PHPExcel_IOFactory::createWriter($objPHPExcel, 'Excel2007');
header('Content-Type: application/vnd.ms-excel');
header('Content-Disposition: attachment;filename="myFile.xls"');
header('Cache-Control: max-age=0');
$objWriter->save('php://output');
exit();
}
echo 'a problem has occurred... no data retrieved from the database';
PHPExcel is definitely outputting data from the query, I can see bits and pieces of plaintext, but it is surrounded by a ton of random characters as if though I am looking at the contents of a compressed or compiled piece of data.
For example:
PKâh¿>G’D²Xð[Content_Types].xml­”MNÃ0…÷œ"ò%nY „švAa •(0ö¤±êØ–gúw{&i‰#ÕnbEö{ßøyìÑdÛ¸l mð¥‘×ÁX¿(ÅÛü)¿’òF¹à¡;#1_滘±Øc)j¢x/%ê…Eˆày¦
Any pointers would be extremely appreciated

Answer 1

Your problem is certainly in outputting more content than just Excel data (which is contained in output buffer).
To solve your problem, just call
ob_clean(); //this will clean the output buffer
before sending header.

Answer 2

The problem will likely be resolved by matching the correct writer types to the correct content-types and file extension.
XLSX (office 2007+):
Writer : Excel2007 (PHPExcel_Writer_Excel2007)
Content-Type: application/vnd.openxmlformats-officedocument.spreadsheetml.sheet
XLS (before office 2007):
Writer : Excel5 (PHPExcel_Writer_Excel5)
Content-Type: application/vnd.ms-excel