I'm using a SelectBox for an optional field. When first rendered, the SelectBox has no selection. If you select something, there's no way to unset the SelectBox, all you can do is select a different option. What is the correct way to allow the user to unset the SelectBox?
Adding an empty record to the SelectBox's store feels like a kludge. The SelectBox for the optional field in question shares a store with another SelectBox which is not optional. It would be wrong to add an empty record to the store since it would be invalid in the case of the required field. It also feels wrong to create a whole separate store just for the optional field. Is this use case supported? If not, what would be the correct way to support it? Perhaps SelectBox could accept a config parameter "allowUnset", which if true adds a blank option to the top of the list.