code: function disableSwitch(oldId, checkedId) {
      // checkedId not used yet
      if (oldId || oldId === 0) {
        var child = comp.widget;
        child = child && child[oldId];
        child = child && child.component;
  
        if (child && child.navWillLeave) {
          // GroundXX.navWillLeave defined
          var info = child.navWillLeave();
          if (!info || typeof info == 'string' && !window.confirm(info)) return true; // navWillLeave() return false, or confirm(sMsg) denied
        }
      }
      return false;
    }
docs: failed