import { EventData , Page , Observable , Frame } from '@nativescript/core' ; export function navigatingTo ( args ) { const page = < Page > args . object ; page . bindingContext = new TestPage ( ) ; } export function onNavBtnTap ( args ) { Frame . topmost ( ) . goBack ( ) ; } export class TestPage extends Observable { constructor ( ) { super ( ) ; } get test ( ) : string { return '\ntest' ; } }