File extension or file is not valid at the time export excel using spout library in php

Question

I am facing problem in export excel using spout library. I don't know where is the issue in my code. I don't know much about spout library. I have tried many times but the same error occurs again and again. Please guide me where is the issue.

Code:

<?php 
include('php_script/db.php');
use Box\Spout\Common\Type;
use Box\Spout\Writer\Style\Border;
use Box\Spout\Writer\Style\BorderBuilder;
use Box\Spout\Writer\Style\Color;
use Box\Spout\Writer\Style\StyleBuilder;
use Box\Spout\Writer\WriterFactory;
include('php_script/spout/src/Spout/Autoloader/autoload.php');  
$sql = mysqli_query($con,"select * from person ");
$border = (new BorderBuilder())
        ->setBorderBottom(Color::GREEN, Border::WIDTH_THIN, Border::STYLE_DASHED)
        //->setFontColor(Color::BLUE)
        //->setBackgroundColor(Color::YELLOW)
        ->build();
    $style = (new StyleBuilder())
        ->setBorder($border)
        ->build();
    $filePath = "person".date("Y-m-d-H-i-s").'.xlsx';
    $writer = WriterFactory::create(Type::XLSX);
    $writer->openToFile($filePath);

    $array = ['TYPE'];
    
    $writer->addRowWithStyle($array, $style);

    
   
    while( $rows = mysqli_fetch_assoc($sql)) {
   
    $Type_subsidiary = $rows['Type_subsidiary'];
    $data =  [$Type_subsidiary];
    $writer->addRow($data);
    }

    $writer->close();
     if (file_exists($filePath)) {
            header('Content-Description: File Transfer');
            header('Content-Type: application/octet-stream');
            header('Content-Disposition: attachment; filename="'.basename($filePath).'"');
            header('Expires: 0');
            header('Cache-Control: must-revalidate');
            header('Pragma: public');
            header('Content-Length: ' . filesize($filePath));
            readfile($filePath);
            exit;
        }


?>

Error:

Excel cannot open the file 'person2018-09-19-07-20-30.xlsx' because the file format or file extension is not valid. Verify that the file has not been corrupted and that the file extension matches the format of the file

Answer 1

have you tried to let spout create and "send" the file directly to browser without specifying headers as specified in their doc http://opensource.box.com/spout/getting-started/ ?

$writer->openToBrowser($fileName); // stream data directly to the browser

Hope this helps, in our applications (based on Symfony), we use spout but no need to specify headers and filepath.