Binding - BeanItem - Support nulls in intermediate path

Hi i’m currently facing a problem with Vaddin 6.8.8. where i’m using a beanItem as a datasource to bind the form with a specific bean.

Class SalleDeClasse {
	int numeroDeClasse;
	Eleve eleve;
}
Class Eleve {
	string nom;
}

I want to be able to bind the property eleve of the class SalleDeClasse to a UI field without having to create the instance. Use a sort of channel that will allow me to bind it without an actual instance.

Can someone assist me on that .