image_upload_xhr.js

let fileInput = document.getElementById('file_chooser');

fileInput.addEventListener('change', function(e) {
  
  var file = this.files[0];
  var fd = new FormData();
  fd.append("file", file);
  
  var request = new XMLHttpRequest();
  request.open('POST', 'http:myserver.com/upload');
    
  request.upload.onprogress = function(event) {
    console.log(`Uploaded ${event.loaded} of ${event.total} bytes`);
  };

  request.upload.onload = function() {
    console.log(`Upload finished successfully.`);
  };

  request.upload.onerror = function() {
    console.log(`Error during the upload: ${request.status}`);
  };
  
  xhr.send(fd);
  
});