gets the submenu object of a menu item (if any)
id | string| number | menu item ID |
object | object of a child menu (submenu), if any |
$$("mymenu").getSubMenu(id);
The method helps retrieve properties of submenu items:
$$("mymenu").attachEvent("onItemClick", function(id){
var submenu = this.getSubMenu(id);
if(submenu)
//returns text value of a clicked menu item
webix.message("Click: " + submenu.getItem(id).value);
});