Liferay Upload Folders javascript

liferay-upload-folders.js

var URL_DL_ADD_FOLDER = '/dlapp/add-folder';

var uploader = this._getUploader();

var uploadFileTree = function(treeNode, folderId) {
  return new A.Promise(function(resolve, reject) {
    if (treeNode.isFile) {
      treeNode.file(
        function(file) {
          var fileHTML5 = new A.FileHTML5(file);

          var uploadURL = instance._getUploadURL(folderId);

          uploader.once('uploadcomplete',
            function() {
              resolve(treeNode);
            }
          );

          uploader.once('uploaderror',
            function() {
              reject(treeNode);
            }
          );

          uploader.upload(fileHTML5, uploadURL);
        }
      );
    }
    else if (treeNode.isDirectory) {
      var appViewSelect = instance._appViewSelect,
        folder = appViewSelect.get('selectedFolder'),
        repositoryId = folder.repositoryId;

      Liferay.Service(
        URL_DL_ADD_FOLDER,
        {
          description: null,
          name: treeNode.name,
          parentFolderId: folderId,
          repositoryId: repositoryId
        },
        function(response) {
          var directoryReader = treeNode.createReader(),
            folderId = response.folderId;

          directoryReader.readEntries(
            function(entries) {
              var promises = A.Array.map(
                entries,
                function(item, index) {
                  return uploadFileTree(item, folderId);
                }
              );

              A.Promise.all(promises).then(resolve);
            }
          );
        }
      );
    }
  });
};