XHR2

gistfile1.html

<progress min="0" max="100" value="0">0% complete</progress>


<script>
function upload(blobOrFile) {
  var xhr = new XMLHttpRequest();
  xhr.open('POST', '/server', true);
  xhr.onload = function(e) { ... };

  // Listen to the upload progress.
  var progressBar = document.querySelector('progress');
  xhr.upload.onprogress = function(e) {
    if (e.lengthComputable) {
      progressBar.value = (e.loaded / e.total) * 100;
      progressBar.textContent = progressBar.value; // Fallback for unsupported browsers.
    }
  };

  xhr.send(blobOrFile);
}

// Take care of vendor prefixes.
BlobBuilder = window.MozBlobBuilder || window.WebKitBlobBuilder || window.BlobBuilder;

var bb = new BlobBuilder();
bb.append('hello world');

upload(bb.getBlob('text/plain'));
</script>