title: Angular 2 Formbuilder with Observables as default values
body: <p>I have a problem with the default value of an Angular 2 Form (formbuilder):
  My default values are observables (which I'm retrieving from a server), so I can't implement them like this:</p>
  
  <pre><code>export class UserComponent implements OnInit{
  
  userForm: ControlGroup;
  userData: any; // Initialise the observable var
  
  ngOnInit():any {
  
      this.userData = this._dataService.getAllData() // My Observable
          .subscribe(
              data =&gt; {
                  this.userData = data;
              }
          );
  
      this.userForm = this._formBuilder.group({
                    // below the default value
          'username': [this.userData.username, Validators.compose([ 
              this.usernameValid
          ])]
  }
  </code></pre>
  
  <p>Someone an idea what I need to change? Because the form displays nothing inside the input fields...</p>