code: func (d ShareItemsBtnDef) OnClick(e *react.SyntheticMouseEvent) {
  	go func() {
  		sharedURL, err := d.shareSelection()
  		if err != nil {
  			dom.GetWindow().Alert(fmt.Sprintf("%v", err))
  			return
  		}
  		prefix, err := d.urlPrefix()
  		if err != nil {
  			dom.GetWindow().Alert(fmt.Sprintf("Cannot display full share URL: %v", err))
  			return
  		}
  		sharedURL = prefix + sharedURL
  		anchorText := sharedURL[:20] + "..." + sharedURL[len(sharedURL)-20:]
  		// TODO(mpl): move some of the Dialog code to Go.
  		d.Props().callbacks.ShowSharedURL(sharedURL, anchorText)
  	}()
  }
docs: // On success, handleShareSelection calls d.showSharedURL with the URL that can
  // be used to share the item. If the item is a file, the URL can be used directly
  // to fetch the file. If the item is a directory, the URL should be used with
  // pk-get -shared.