Function flip_toggle_on_click 

pub fn flip_toggle_on_click(
    clicks: MessageReader<'_, '_, ClickEvent>,
    q: Query<'_, '_, &mut Toggleable>,
    parents: Query<'_, '_, &ChildOf>,
    out: MessageWriter<'_, ToggleChanged>,
)

Flip Toggleable::checked every time the entity - or a child of it, such as the spawned ToggleKnob - receives a ClickEvent. Fires ToggleChanged so the script host can echo it to on_toggle(id, checked).