ID in binding template

Hi Friends,

I am creating navigationbar items using binding (from json data). Here is how the template looks.

     var oNavBarItemTemplate = new sap.ui.ux3.NavigationItem({

        key : "{key}",

            text : "{text}",

            tooltip: "{tooltip}"

        });

I have IDs for the each item in my json data. How do I assign this ID to each of the items that get created?

Thanks

Krishna