PHPExcel outputting zeros as blank cells

Question

I'm building a WordPress plugin using PHPExcel to export reports of student attendance. So far, I'm able to successfully take the array of student data (including attendance) and convert and download it as a spreadsheet. Unfortunately, there's an odd bug: when a student has attended zero events, that cell on the spreadsheet is blank instead of showing a zero. I'd prefer it come out with an actual zero, but I can't find a way to do that. Here's my script:

error_reporting( E_ALL);
ini_set( 'include_path', ini_get( 'include_path' ).';../Classes/' );

include 'PHPExcel.php';
include 'PHPExcel/Writer/Excel2007.php';

$objPHPExcel = new PHPExcel();

$objPHPExcel->setActiveSheetIndex( 0 );
$objPHPExcel->getProperties()->setCreator( $user );
$objPHPExcel->getProperties()->setLastModifiedBy( $user );
$objPHPExcel->getProperties()->setTitle( $title );
$objPHPExcel->getProperties()->setSubject( $title );
$objPHPExcel->getProperties()->setDescription( $title );
$objPHPExcel->getActiveSheet()->fromArray( $data, null, 'A1' );
$objPHPExcel->getActiveSheet()->getStyle('A1:H1')->getFont()->setBold(true);

$columns = array( 'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H' );

foreach ( $columns as $column ) {

    $objPHPExcel->getActiveSheet()->getColumnDimension($column)->setAutoSize(true);

} // End $columns foreach

$file_name = str_replace( ' ', '_', $title);

if ( $_POST['type'] == 'spreadsheet' ) {

header( 'Content-type: application/vnd.ms-excel' ); 
header( 'Content-Disposition: attachment; filename="' . $file_name . '.xls"' );

$objWriter = new PHPExcel_Writer_Excel2007( $objPHPExcel );
$objWriter->save( 'php://output' );

} 

$data contains the array of student info, which is structured like this:

Array (
    [0] => Array (
        [0] => First Name
        [1] => Last Name
        [2] => BU ID
        [3] => Barcode
        [4] => Major
        [5] => Class
        [6] => Seminars
        [7] => Showcases
    )

    [1] => Array (
        [first_name] => Seth
        [last_name] => Abel
        [buid] => B00385307
        [barcode] => 100324707
        [student_major] => CMM
        [class] => MBU2100
        [seminar] => 0
        [showcase] => 1
    )

    [2] => Array (
        [first_name] => Zachary
        [last_name] => Abend
        [buid] => B00373103
        [barcode] => 100291996
        [student_major] => MBU
        [class] => MBU2100
        [seminar] => 0
        [showcase] => 1
    )
.
.
.
)

As you can see is the example data, the those students have each attended 1 showcase, but zero seminars. When this spreadsheet is downloaded and opened in Excel, the 1 shows up fine, but the seminar cells are blank. Since I'm using the fromArray() function to populate the spreadsheet, is there something I should do to make those zeros appear properly?

Answer 1

I think you are a victim of loosely-typed comparisons here - you have specified null as your second parameter to fromArray(), which represents the Value in source array that stands for blank cell. Since null == 0 this means that zero will result in a blank cell unless you set the fourth argument to true.

Try changing:

$objPHPExcel->getActiveSheet()->fromArray( $data, null, 'A1' );

...to...

$objPHPExcel->getActiveSheet()->fromArray( $data, null, 'A1', true );