title: *ngFor object attribute undefined
body: <p>I'm starting on Angular 2 coming from Angular 1, and I can't figure how to use ngFor on an object's attribute.
  <code>this.myVar</code> is defined upon the result of an HTTP request, which defines the <code>attr</code> attribute.</p>
  
  <p>Here's my code:</p>
  
  <pre><code># my_page.ts
  import {Page} from 'ionic-angular';
  import {MyService} from '../../services/my_service';
  
  @Page({
    templateUrl: 'build/pages/my_page/my_page.html',
    providers: [MyService]
  })
  
  
  export class MyPage {
    public myVar;
  
    constructor(private myService: MyService) {
      this.myService.fetch().subscribe(
        data =&gt; this.myVar = data
      );
    }
  }
  
  # my_page.html
  &lt;div *ngFor="#item of myVar.attr"&gt;
  &lt;/div&gt;
  </code></pre>
  
  <p>And this is the error:</p>
  
  <blockquote>
    <p>EXCEPTION: TypeError: Cannot read property 'attr' of undefined in [myVar.attr in ...]</p>
  </blockquote>
  
  <p>Thank you!</p>