Single form control (without FormGroup)

a2-forms-singleControl

<!--
Sometimes, we don’t need a FormGroup, as our form might only consist of a single form control. Think of a search field that let’s you search for products in an e-commerce application. Technically, we don’t even need a <form> element for that.
Angular comes with a directive formControl which doesn’t have to be inside a formGroup. We can simply add it to a single form control and are ready to go:
-->

<!-- no surrounding form -->
<input type="search" [formControl]="seachControl">

<!--
The cool thing about form controls in Angular is, 
that we can listen reactively for changes that are happening to that control. 
Every form controls exposes an Observable propery valuesChanges() that we can subscribe to. 
So in order to get notified about changes in the example above, all we have to do is:
-->

@Component()
export class SearchComponent implements OnInit {

  searchControl = new FormControl();

  ngOnInit() {
    this.searchControl.valueChanges.subscribe(value => {
      // do something with value here
    });
  }
}

There's a typo in [formControl]="seachControl"
<input type="search" [formControl]="searchControl">

Otherwise it will always error out "Cannot find control with unspecified name attribute"