Sample code to download and open an Asset

Question

For anyone who wants to download an asset from the web and load it into your Adobe application, this is how I did it:
// .js
var TMP_FOLDER="/tmp/com.mb.extension/";
var doOpen = function(uri) {
          var xhr = new XMLHttpRequest();
          xhr.open("GET", uri, true);
          xhr.responseType = "blob";
          xhr.onload = function(event) {
                    var blob = this.response;
                    var data;
                    blobToBase64(blob, function(result) {
                              data = result;
                              var file = TMP_FOLDER+name;
                              window.cep.fs.writeFile(file, data, cep.encoding.Base64);
                              doOpenFile(file);
          xhr.send();
function doOpenFile(file) {
          var ppid = "ILST";
          var extScript = "$._ext_"+ppid+".open('"+file+"')";
          evalScript(extScript);
var base64ToBlob = function(base64, callback) {
  var binary = atob(base64);
  var len = binary.length;
  var buffer = new ArrayBuffer(len);
  var view = new Uint8Array(buffer);
  for (var i = 0; i < len; i++) {
       view[i] = binary.charCodeAt(i);
  callback(new Blob([view]));
// .jsx
$._ext_ILST={
    open : function(path) {
        openDocument(path);
var openDocument = function(path) {
    return app.open(File(path));

Answer 1

I don't know why, but when I use this code. The file was downloaded right, but Illustrator doesn't open the file.
When doOpenFile is fired the args are correct, because I have debug it in console. But I think the problem is with the JSX file, sure I'm doing something wrong.
Anybody could guide me about it?
I'm newbie trying to script Adobe Extensions.