JAVASCRIPT

How to subscribe changes to property of a directive

<input [myDirective]="myService.parameter" myServiceValue="{{myService.value}}" ... >


@Directive({
  selector: '[myDirective]'
})
export class parameterDirective implements OnInit, OnChanges {
  @Input('myDirective') parameter: parameter;
  @Input() myServiceValue: string;

  constructor(private el: ElementRef, private renderer: Renderer) {
  }

  ngOnInit(): void {
  }

  ngOnChanges(changes: SimpleChanges): void {
    switch (this.parameter) {
      case parameter.EnumValue:
        this.renderer.setElementClass(this.el.nativeElement, "my-class", changes.myServiceValue.currentValue > 100);
        break;
      default:
    }

  }
}