Not possible to know which item with sub-items was clicked

[eeschiavo]

I would like to apply a css class to an item if it has sub items and when it's state is "open". I defined a custom CustomLink and, of corse, I can attach an "onClick" event inside it but the problem is when other elements are clicked my CustomLink instance doesn't get updates and I can not change it's internal state removing previous class. Any ideas?

The goal is to highlight a menu item when it's expanded.

Thanks