import { EventData, Observable } from "tns-core-modules/data/observable"; import { Page } from "tns-core-modules/ui/page"; import * as frame from "tns-core-modules/ui/frame"; export function navigatingTo(args: EventData) { const page = args.object; page.bindingContext = new TestPage(); } export function onNavBtnTap(args) { frame.topmost().goBack(); } export class TestPage extends Observable { constructor() { super(); } // new line of span can be set with \n from code behind get test(): string { return "\ntest"; } }