Ajax + PHPExcel not working?

Question

PHP

First time using PHPExcel
have ajax

$(document).ready(function () {
    $('#exelTicket').submit(function (event) {
      event.preventDefault();
      var formValid = true;			
      var expolistall = $("#expolistall").val();
      var formData = new FormData();
      formData.append('expolistall', expolistall);
      $.ajax({
        type: "POST",
        url: "ajax/exelticket.php",
        data: formData,
        contentType: false,
        processData: false,
        cache: false,
        success: function (data) {
          var $data =  JSON.parse(data);
          $('#error').text('');
          if ($data.result == "success") {
            $('#exelTicket').hide();
            $('#msgExelTicket').removeClass('hidden');
          } else {
            $('#error').text('');
          }
        }
      });
    });
  });

php

<?php
define('INCLUDE_CHECK',true);
require_once('../system/mysql.php');
require_once('../system/session.php');
require_once('../system/connect.php');
$data['result']='error';
function validStringLength($string,$min,$max) {
  $length = mb_strlen($string,'UTF-8');
  if (($length<$min) || ($length>$max)) {
    return false;
  } else {
    return true;
  }
}
if ($_SERVER['REQUEST_METHOD'] == 'POST') {
  $data['result']='success';	
  if (isset($_POST['expolistall'])) {
    $expolistall = $_POST['expolistall'];
    if (!validStringLength($expolistall,1,500)) {
      $data['expolistall']='Поля имя содержит недопустимое количество символов.';   
      $data['result']='error';     
    }
  } else {
    $data['result']='error';
  }
}
else
{
  $data['result']='error';
}
if ($data['result']=='success') {
  //тут данные из базы, пока тестовый запуск так что их нет
  
  require_once('../Classes/PHPExcel.php');
  $objPHPExcel = new PHPExcel();	
  $objPHPExcel->setActiveSheetIndex(0)
        ->setCellValue('A1', 'Hello')
        ->setCellValue('B2', 'world!')
        ->setCellValue('C1', 'Hello')
        ->setCellValue('D2', 'world!');				
  $objPHPExcel->getActiveSheet()->setTitle('Название страницы');	
  $objWriter = PHPExcel_IOFactory::createWriter($objPHPExcel, 'Excel5');
  $objWriter->save('php://output');
  $data['result']='success';
}
echo json_encode($data);
?>

When trying to execute, it displays strange characters in the logs.
If you just pull the PHPExcel code into a separate file, it works, creates a file and immediately downloads it by the browser.
How to make it work?
Apologies in advance for my crooked code, this is my first time using PHPExcel

Answer 1

stackoverflow.com/a/36412422/4287929