what.ts

/// <reference path="./typings/angular2/angular2.d.ts" />
/// <reference path="./typings/node/node.d.ts" />
/// <reference path="./typings/rx/rx-lite.d.ts" />

import {Component, View, Injectable, bootstrap, ChangeDetectionStrategy} from 'angular2/angular2';
import * as proc from 'child_process';

@Injectable()
class MyService {
	val: string;

	constructor() {
		this.val = "nothing yet"

		var self = this;
		// This runs, but fires no change event when val is changed.
		proc.exec("false", (err, stdout, stderr) => {
			self.val = "ran false";
		});
		// This runs and DOES fires a change event when val is changed.
		window.setTimeout(() => {
			self.val = "timeout returned;"
		}, 1000);
	}
}

@Component({
	selector: 'my-component',
	viewBindings: [MyService]
})
@View({
	template: '<h1 id="output">My First Angular 2 App: {{_svc.val}}</h1>'
})
class MyComponent {
	private _svc: MyService;

	constructor(svc: MyService) {
		this._svc = svc;
	}
}

bootstrap(MyComponent);