function onMainPageAttach(page) {
  google.script.run.withSuccessHandler( function(resp) {
    page.descendants.ToFolderLink.text = resp.title;
    page.descendants.ToFolderLink.href = resp.link;
  }).getLinkToFolderByProperty();
}

/**
 * @param {widget} widget - Button widget.
 * @param {event}
 */
function onMainInputClick(widget, event) {
  // var widgets = widget.parent.descendants;
  var input = widget.parent.descendants.InputTextBox.value;
  app.popups.ModalLoadingIndicator.visible = true;
  google.script.run.withSuccessHandler( function(resp) {
    var props = app.currentPage.properties;
    props.TitleProperty = resp.title;
    props.UrlProperty = resp.url;
    props.MessageProperty = resp.message;
    app.popups.ModalLoadingIndicator.visible = false;
  }).processMain(input);
}

/**
 * @param {widget} widget - Button widget.
 * @param {event}
 */
function onToFolderButtonClick(widget) {
  var toFolder = widget.parent.descendants.ToFolderTextBox.value;
  widget.parent.descendants.ToFolderTextBox.value = '';
  app.popups.ModalLoadingIndicator.visible = true;
  google.script.run.withSuccessHandler( function(resp) {
    var props = app.currentPage.properties;
    props.ToFolderName = resp.title;
    props.ToFolderUrl = resp.url;
    props.MessageProperty = resp.message;
    app.popups.ModalLoadingIndicator.visible = false;
  }).setToFolderByUrl(toFolder);
}