NgRx @Effect vs createEffect

Question

What is the difference between createEffect vs @Effect annotation in ngrx?

@Injectable()
export class ContactsEffects {

constructor(
    private actions$: Actions,
    private contactsService: ContactsService,
    private contactsSocket: ContactsSocketService
  ) {}


  destroy$ = createEffect( () => this.actions$.pipe(
    ofType(remove),
    pluck('id'),
    switchMap( id => this.contactsService.destroy(id).pipe(
      pluck('id'),
      map(id => removeSuccess({id}))
    ))
  ));

  @Effect()
  liveCreate$ = this.contactsSocket.liveCreated$.pipe(
    map(contact => createSuccess({contact}))
  );

}

Answer 1

@ngrx/effects createEffect for type safety As alternative to the @Effect() decorator, NgRx 8 provides the createEffect function. The advantage of using createEffect is that it’s type-safe, if the effect does not return an Observable<Action> it will give compile errors. The option { dispatch: false } still exists for effects that don’t dispatch new Actions, adding this option also removes the restriction that an effect needs to return an Observable<Action>.

Starting from NgRx 8 by default, automatically resubscribe to the effect when this happens. This adds a safety net for where the unhappy paths were missed. It’s possible to turn this feature off by setting resubscribeOnError to false at the effect level. example:

login$ = createEffect(() => .....), { resubscribeOnError: false });