Thx the *.50beta fixed the issued :
toto = {"cancel":false,"item":{"id":"itemSidebar","prefixIcon":"e-indent-icon tb-icons","tooltipText":"SideBar","htmlAttributes":null,"cssClass":"","template":"","type":"Button","text":"","suffixIcon":"","width":"auto","showTextOn":"Both","overflow":"None","showAlwaysInPopup":false,"align":"Left"},"name":"clicked","originalEvent":{"cancel":false,"element":null,"event":null,"isInteracted":false,"model":null}}