lib/loaders/LoaderBase.js
function (ev) {
    var loaded = ev.loaded || ev.position;
    var totalSize = ev.total || ev.totalSize;

    if (totalSize) {
      this._dispatchProgress(loaded / totalSize);
    } else {
      this._dispatchProgress(0);
    }
  }
function (ev) {
    var loaded = ev.loaded || ev.position;
    var totalSize = ev.total || ev.totalSize;

    if (totalSize) {
      this._dispatchProgress(loaded / totalSize);
    } else {
      this._dispatchProgress(0);
    }
  }
function ( ev ) { var loaded = ev . loaded || ev . position ; var totalSize = ev . total || ev . totalSize ; if ( totalSize ) { this . _dispatchProgress ( loaded / totalSize ) ; } else { this . _dispatchProgress ( 0 ) ; } }
This callback will be called when the XHR progresses in its load.

@method _onProgress
@protected
@param  {XMLHttpRequestProgressEvent} ev This event contains data for the progress of the load
This callback will be called when the XHR progresses in its load .