Angular2 ngModel在异步回调后未更新

Question

Why angular2 two way data binding doesn' t work in this scenario ?

<span style="color:white">{{searchLocation}}</span>
<input  name="searchLocation" type="text" placeholder="Search" [(ngModel)]="searchLocation">
<button class="btn btn-outline-success" type="submit" (click)="search()">Search</button>

The target component is HeaderComponent

export class HeaderComponent implements OnInit {

  searchLocation: string;
  @Output() locationFound: EventEmitter<Position> = new EventEmitter<Position>();

  constructor(private _locationService: LocationService) { }

  ngOnInit() {
     this.searchLocation ="";
  }

  search():void{

    this._locationService.geocodeAddress(this.searchLocation)
        .subscribe((position:Position)=>{
          this.searchLocation ="new value";
          this.locationFound.emit(position);
    });
  }
}

After the subscribe block the searchLocation change but the view is not updated.

I hope somebody can help me

Answer 1

      this.searchLocation ="";

searchLocation is assigned to null. If null is present it won't update the DOM. Try giving some valid string.