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                <div id="drop-area">
  <form class="my-form">
    <p>Upload multiple files with the file dialog or by dragging and dropping images onto the dashed region</p>
    <input type="file" id="fileElem" multiple accept="image/*" onchange="handleFiles(this.files)">
    <label class="button" for="fileElem">Select some files</label>
  <progress id="progress-bar" max=100 value=0></progress>
  <div id="gallery" /></div>
<div class="note"><strong>Note: I've Removed the ability to actually upload files (it will error out silently since there is no error handler, so it'll still appear to work) because you guys were constantly filling up my Cloudinary account. Please <a href="">create your own account</a> and replace the "joezim007" and "ujpu6gyk" bits in the JavaScript with your own account's information.</strong></div>


                body {
  font-family: sans-serif;
a {
  color: #369;
.note {
  width: 500px;
  margin: 50px auto;
  font-size: 1.1em;
  color: #333;
  text-align: justify;
#drop-area {
  border: 2px dashed #ccc;
  border-radius: 20px;
  width: 480px;
  margin: 50px auto;
  padding: 20px;
#drop-area.highlight {
  border-color: purple;
p {
  margin-top: 0;
.my-form {
  margin-bottom: 10px;
#gallery {
  margin-top: 10px;
#gallery img {
  width: 150px;
  margin-bottom: 10px;
  margin-right: 10px;
  vertical-align: middle;
.button {
  display: inline-block;
  padding: 10px;
  background: #ccc;
  cursor: pointer;
  border-radius: 5px;
  border: 1px solid #ccc;
.button:hover {
  background: #ddd;
#fileElem {
  display: none;


                // ************************ Drag and drop ***************** //
let dropArea = document.getElementById("drop-area")

// Prevent default drag behaviors
;['dragenter', 'dragover', 'dragleave', 'drop'].forEach(eventName => {
  dropArea.addEventListener(eventName, preventDefaults, false)   
  document.body.addEventListener(eventName, preventDefaults, false)

// Highlight drop area when item is dragged over it
;['dragenter', 'dragover'].forEach(eventName => {
  dropArea.addEventListener(eventName, highlight, false)

;['dragleave', 'drop'].forEach(eventName => {
  dropArea.addEventListener(eventName, unhighlight, false)

// Handle dropped files
dropArea.addEventListener('drop', handleDrop, false)

function preventDefaults (e) {

function highlight(e) {

function unhighlight(e) {

function handleDrop(e) {
  var dt = e.dataTransfer
  var files = dt.files


let uploadProgress = []
let progressBar = document.getElementById('progress-bar')

function initializeProgress(numFiles) {
  progressBar.value = 0
  uploadProgress = []

  for(let i = numFiles; i > 0; i--) {

function updateProgress(fileNumber, percent) {
  uploadProgress[fileNumber] = percent
  let total = uploadProgress.reduce((tot, curr) => tot + curr, 0) / uploadProgress.length
  progressBar.value = total

function handleFiles(files) {
  files = [...files]

function previewFile(file) {
  let reader = new FileReader()
  reader.onloadend = function() {
    let img = document.createElement('img')
    img.src = reader.result

function uploadFile(file, i) {
  var url = ''
  var xhr = new XMLHttpRequest()
  var formData = new FormData()'POST', url, true)
  xhr.setRequestHeader('X-Requested-With', 'XMLHttpRequest')

  // Update progress (can be used to show progress indicator)
  xhr.upload.addEventListener("progress", function(e) {
    updateProgress(i, (e.loaded * 100.0 / || 100)

  xhr.addEventListener('readystatechange', function(e) {
    if (xhr.readyState == 4 && xhr.status == 200) {
      updateProgress(i, 100) // <- Add this
    else if (xhr.readyState == 4 && xhr.status != 200) {
      // Error. Inform the user

  formData.append('upload_preset', 'ujpu6gyk')
  formData.append('file', file)