用Ajax实现简单的TYPO3 Fluid文件上传？

<form id="uploadForm" method="post" enctype="multipart/form-data">
  <input type="file" name="file" id="fileInput">
  <button type="submit">上传文件</button>
</form>
<div id="message"></div>

document.getElementById('uploadForm').addEventListener('submit', function(e) {
  e.preventDefault();
  
  var fileInput = document.getElementById('fileInput');
  var file = fileInput.files[0];
  
  var formData = new FormData();
  formData.append('file', file);
  
  var xhr = new XMLHttpRequest();
  xhr.open('POST', '/upload.php', true);
  
  xhr.onload = function() {
    if (xhr.status === 200) {
      document.getElementById('message').innerHTML = '文件上传成功！';
    } else {
      document.getElementById('message').innerHTML = '文件上传失败。';
    }
  };
  
  xhr.send(formData);
});

<?php
$targetDir = 'uploads/';
$targetFile = $targetDir . basename($_FILES['file']['name']);

if (move_uploaded_file($_FILES['file']['tmp_name'], $targetFile)) {
  echo '文件上传成功！';
} else {
  echo '文件上传失败。';
}
?>