PHPExcel + Symfony2

AdminController.php

<?php

    $participantModel = new ParticipantModel($this->container);
    $filename = "participations_" . date("d_m_Y__H_i") . "_export.xls";
    
    $excel = $participantModel->getExcelHandler();
    $writer = \PHPExcel_IOFactory::createWriter($excel, "Excel5");
    
    $handle = fopen("php://temp", "a");
    $writer->save($handle);
    rewind($handle);
    $content = stream_get_contents($handle);
    
    $response = new Response( $content );
    $response->headers->set('Content-Type', 'application/vnd.ms-excel');
    $response->headers->set('Content-Disposition', 'attachment; filename="' . $filename . '"');
    return $response;

$participantModel->getExcelHandler() returns the (filled) excel object of type \PHPExcel.