title: Add additional information to the PrimeNG FileUpload data transfer
body: <p>I'm looking to send additional information with files that are being uploaded with the primeng fileupload component. Basically, I need to know what these uploaded files are relevant to.</p>
  
  <p>I can add headers in the "onBeforeSend" function like the Authorization code as in the example below.  Where could I add additional information e.g. 'DocumentID': 'A123' </p>
  
  <pre><code>onBeforeSend(event) {
      event.xhr.setRequestHeader("Authorization", 'Bearer ' + this.authService.getAccessToken());
  } 
  </code></pre>
  
  <p>Anyone know?</p>
  
  <p>Thanks</p>