Angular/RxJs When should I unsubscribe from `Subscription`

Question

When should I store the Subscription instances and invoke unsubscribe() during the NgOnDestroy life cycle and when can I simply ignore them?

Answer 1

Based on : Using Class inheritance to hook to Angular 2 component lifecycle

Another generic approach:

export abstract class UnsubscribeOnDestroy implements OnDestroy {
  protected d$: Subject;

  constructor() {
    this.d$ = new Subject();

    const f = this.ngOnDestroy;
    this.ngOnDestroy = () => {
      f();
      this.d$.next();
      this.d$.complete();
    };
  }

  public ngOnDestroy() {
    // no-op
  }

}

And use :

@Component({
    selector: 'my-comp',
    template: ``
})
export class RsvpFormSaveComponent extends UnsubscribeOnDestroy implements OnInit {

    constructor() {
        super();
    }

    ngOnInit(): void {
      Observable.of('bla')
      .takeUntil(this.d$)
      .subscribe(val => console.log(val));
    }
}