How to monitor the 'progress' of the upload?

use XMLHttpRequest, i listener ‘progress’, as below:

var XHR = new XMLHttpRequest();
XHR.upload.addEventListener("progress", function(e) {
  if (e.lengthComputable) {　　　　　　
    var percentComplete = Math.round(e.position * 100 / e.total);
    console.log(percentComplete);
  }
}, false);

How do this with fetch ?

[wmertens]

@domenic I don’t understand how to use that snippet to monitor upload progress - in the spec I can only see streams for the response object, not the request object…

[domenic]

This should do the trick: https://gist.github.com/domenic/95e689d0be5e24fb08ec