title: How to send custom attribute for chunk file upload
body: <p>I'm using <code>blueimp</code>  file upload plugin but I don't for multiple <code>files</code> but I don't know how to send custom attributes. I wanted to send all these custom attribute to <strong>server</strong> with each <code>chunk</code> no problem(<strong>how we send  <code>formData</code></strong>). How we send for <code>formData</code> similarly, can I send attribute?</p>
  
  <pre><code>var formdata = new formData();
  
  formdata.append('filename',currentFile[i]);
  
  formdata.append('filesize',currentFile[i].size);
  </code></pre>
  
  <p><strong>Note: I wanted to send the data in <code>chunks</code></strong></p>
  
  <p>Here is a code what I'm trying jsfiddle(in firefox opens perfectly): <a href="http://jsfiddle.net/davidchase03/ChJ9B/" rel="nofollow noreferrer">http://jsfiddle.net/davidchase03/ChJ9B/</a></p>
  
  <p><strong>HTML</strong></p>
  
  <pre><code>&lt;input id="fileupload" type="file" name="files[]" multiple&gt;
  &lt;div class="progress"&gt;
      &lt;div class="meter" style="width: 0%;"&gt;&lt;/div&gt;
  &lt;/div&gt;
  &lt;div class="data"&gt;&lt;/div&gt;
  </code></pre>
  
  <p><strong>JavaScript</strong></p>
  
  <pre><code>$(function () {
      $('#fileupload').fileupload({
          url: '/echo/json/',
          maxChunkSize: 1048576,
          maxRetries: 3,
          dataType: 'json',
          multipart: false,
          progressall: function (e, data) {
              var progress = parseInt(data.loaded / data.total * 100, 10),
                  meter = $('.progress .meter'),
                  percent = progress + '%';
              meter.css('width', percent).text(percent);
          },
          add: function (e, data) {
              data.context = $('&lt;p/&gt;').text('Uploading...').appendTo('.data');
              data.submit();
          },
          done: function (e, data) {
              data.context.text('Upload finished.');
          },
          fail: function (e, data) {
              data.context.text('Upload failed.');
              $('.progress').addClass('alert');
              console.warn('Error: ', data);
  
          }
      }).on('fileuploadchunksend', function (e, data) {
           // if (data.uploadedBytes === 3145728 ) return false;
      }).on('fileuploadchunkdone', function (e, data) {
  
      });
  });
  </code></pre>
  
  <p><strong>Question</strong>: to make you clear this is what I wanted <a href="https://stackoverflow.com/questions/50726799/how-to-send-custom-data-to-server-using-jquery-file-uploader">How to send custom data to server using jquery-file-uploader</a></p>
  
  <p>Please help me thanks in advance!!!</p>