Question

I am wondering how to get the progress of a file upload using XMLHTTPRequest. In Firefox the onprogress method does not fire at all, and in chrome it only fires after the file has finished uploading.

function fileUpload(file)
{
    var formData = new FormData();
    formData.append('file', file);

    var xhr = new XMLHttpRequest();
    xhr.onprogress = function(e)
    {
        alert('progress');
    };

    xhr.open('POST', 'post.php', true);

    xhr.send(formData);  // multipart/form-data
}

Answer 1

Try xhr.upload.onprogress. In the XMLHttpRequest2 spec XMLHttpRequest have upload attribute.

The ability to register for progress events. Both for downloads (put
listeners on the XMLHttpRequest object itself) and uploads (put
listeners on the XMLHttpRequestUpload object, returned by the upload
attribute).
http://dev.w3.org/2006/webapi/XMLHttpRequest-2/#differences