title: Append Response Data to an Input Form
body: <p>beginner, please be patient....
  i have a file dropzone and when a file is dropped it is buffered in memory by multer to read metadata and then prefill a form in a modal.  This so far works as expected except that the Modal that is opened up has a file input and i try to attach the file from dropzone to this input/form but never got it working. How is it possible to pass the file to the form of the modal?</p>
  
  <p>I tried like: $('#Bild').val(response.bild); without success... </p>
  
  <p>This is the api/filemeta (shortened, just to give idea):</p>
  
  <pre><code>response = {
      datum: createDate,
      uhrzeit: createTime,
      gewaesser: wtr,
      bild: req.file,
  }
  res.send(response);
  </code></pre>
  
  <p>This is the dropzone:</p>
  
  <pre class="lang-js prettyprint-override"><code>$("#uploadfile").click(function() {
    $("#file").click();
  });
  
  $("#file").change(function() {
    var fd = new FormData();
    var files = $('#file')[0].files[0];
    fd.append('file', files);
    $.ajax({
      type: "POST",
      url: '/api/filemeta',
      data: fd,
      processData: false,
      contentType: false,
      success: function(response) {
        //alert(response);
        $('#id_datum').val(response.datum);
        $('#id_uhrzeit').val(response.uhrzeit);
        $('#id_gewaesser').val(response.gewaesser);
        $("#addNew").modal('show');
      }
    });
  });
  </code></pre>
  
  <pre class="lang-html prettyprint-override"><code>This is the Modal (shortened):
  
  &lt;div class="modal fade" id="addNew" tabindex="-1" role="dialog" aria-labelledby="exampleModalLabel" aria-hidden="true"&gt;
    &lt;form id="faenge-data" method="post" enctype="multipart/form-data"&gt;
      &lt;input id="id_picture" type="file" name="Bild" accept="image/*" multiple="multiple" /&gt;
    &lt;/form&gt;
  &lt;/div&gt;
  &lt;div class="modal-footer"&gt;
    &lt;button type="submit" class="menuebuttons"&gt;Speichern&lt;/button&gt;
    &lt;button type="button" class="cancelbtn" data-dismiss="modal" aria-label="Close"&gt;Abbrechen&lt;/button&gt;
  &lt;/div&gt;
  </code></pre>