Simple preloading indicator.
import { SpinnerModule } from 'angular2-spinner';
....
imports: [
SpinnerModule,
],
...
<spinner [size]="20" [tickness]="1" [color]="#ff66ff"></spinner>
<button [disabled]="working" md-icon-button (click)="save()">
<md-icon *ngIf="!working">save</md-icon>
<spinner *ngIf="working" [tickness]="1" [size]="20"></spinner>
</button>