import observableModule = require("data/observable"); import pageModule = require("ui/page"); class MainViewModel extends observableModule.Observable { private _item: any; constructor() { super(); this.item = { Title: "Alabala" }; } get item(): any { return this._item; } set item(value: any) { if (this._item !== value) { this._item = value; this.notifyPropertyChanged("item", value); } } notifyPropertyChanged(propertyName: string, value: any) { this.notify({ object: this, eventName: observableModule.Observable.propertyChangeEvent, propertyName: propertyName, value: value }); } } var viewModel = new MainViewModel(); export function pageLoaded(args: observableModule.EventData) { var page = args.object; page.bindingContext = viewModel; }