dennismoha/index.html

## index.html
<!DOCTYPE HTML>
<html lang="en-US">
<head>
  <meta charset="UTF-8">
  <title>test upload by chunk</title>
</head>
<body>
  <input type="file" id="f" />

  <script src="script.js"></script>
</body>
</html>

## script.js
(function() {

var f = document.getElementById('f');

if (f.files.length)
  processFile();

f.addEventListener('change', processFile, false);


function processFile(e) {
  var file = f.files[0];
  var size = file.size;
  var sliceSize = 256;
  var start = 0;

  setTimeout(loop, 1);

  function loop() {
    var end = start + sliceSize;

    if (size - end < 0) {
      end = size;
    }

    var s = slice(file, start, end);

    send(s, start, end);

    if (end < size) {
      start += sliceSize;
      setTimeout(loop, 1);
    }
  }
}


function send(piece, start, end) {
  var formdata = new FormData();
  var xhr = new XMLHttpRequest();

  xhr.open('POST', '/upload', true);

  formdata.append('start', start);
  formdata.append('end', end);
  formdata.append('file', piece);

  xhr.send(formdata);
}

/**
 * Formalize file.slice
 */

function slice(file, start, end) {
  var slice = file.mozSlice ? file.mozSlice :
              file.webkitSlice ? file.webkitSlice :
              file.slice ? file.slice : noop;

  return slice.bind(file)(start, end);
}

function noop() {

}

})();
	<!DOCTYPE HTML>
	<html lang="en-US">
	<head>
	<meta charset="UTF-8">
	<title>test upload by chunk</title>
	</head>
	<body>
	<input type="file" id="f" />

	<script src="script.js"></script>
	</body>
	</html>
	(function() {

	var f = document.getElementById('f');

	if (f.files.length)
	processFile();

	f.addEventListener('change', processFile, false);


	function processFile(e) {
	var file = f.files[0];
	var size = file.size;
	var sliceSize = 256;
	var start = 0;

	setTimeout(loop, 1);

	function loop() {
	var end = start + sliceSize;

	if (size - end < 0) {
	end = size;
	}

	var s = slice(file, start, end);

	send(s, start, end);

	if (end < size) {
	start += sliceSize;
	setTimeout(loop, 1);
	}
	}
	}


	function send(piece, start, end) {
	var formdata = new FormData();
	var xhr = new XMLHttpRequest();

	xhr.open('POST', '/upload', true);

	formdata.append('start', start);
	formdata.append('end', end);
	formdata.append('file', piece);

	xhr.send(formdata);
	}

	/**
	* Formalize file.slice
	*/

	function slice(file, start, end) {
	var slice = file.mozSlice ? file.mozSlice :
	file.webkitSlice ? file.webkitSlice :
	file.slice ? file.slice : noop;

	return slice.bind(file)(start, end);
	}

	function noop() {

	}

	})();