PHPExcel arrayToExcelDownload() function

arrayToExcelDownload.php

<?php

function arrayToExcelDownload($data, $filename = FALSE) {

    if(!isset($filename)) {
        $filename = 'crm_export_' . date('m.d.Y') . 'xlsx';
    }

    $excel = new PHPExcel();
    $excel->setActiveSheetIndex(0);

    $excel->getActiveSheet()->setTitle("Raport clienti");

    $col = 0;
    foreach($data[0] as $columnName => $value) {
        $excel->getActiveSheet()->setCellValueByColumnAndRow($col++, 1, $columnName);
    }

    $row = 2;

    foreach ($data as $ach) {
        foreach(array_values($ach) as $columnIndex => $value) {
            $excel->getActiveSheet()->setCellValueByColumnAndRow($columnIndex, $row, $value);
        }
        $row++;
    }

    foreach (range(0, --$col) as $column) {
        $excel->getActiveSheet()->getStyleByColumnAndRow($column, 1)->getFont()->setBold(true);
        $excel->getActiveSheet()->getColumnDimensionByColumn($column)->setAutoSize(true);
    }


    header("Content-Type: application/vnd.ms-excel");
    header("Content-Disposition: attachment; filename='".$filename."'");
    header("Cache-Control: max-age=0");

    $objWriter = PHPExcel_IOFactory::createWriter($excel, "Excel5");
    return $objWriter->save("php://output");

}