ngrx effect - catchError: returning of does not end stream, and the API call does not re-run

Question

I have an effect in NgRX effect, as follows:

$createOrganisation = createEffect(() =>
  this.actions$.pipe(
    ofType(fromOrganisationActions.createOrganisation),
    switchMap((data) => this.organisation.createOrganisation(data)),
    map((response) => fromOrganisationActions.createOrganisationSuccess({ orgId: response.id })),
    catchError((error) => {
      return of(fromOrganisationActions.createOrganisationError(error));
    })
  )
);

However, my stream never seems to end when the catchError is triggered, i.e. in the instance of this.organisation.createOrganisation returning a 400 error.

The action, fromOrganisationActions.createOrganisationError(error) is triggered and my reducer is triggered from this... but if I re-trigger the fromOrganisationActions.createOrganisation effect, this effect runs but the API call is never made a second time.

If I configure it as follows, and dispatch it manually, it works:

$createOrganisation = createEffect(() =>
  this.actions$.pipe(
    ofType(fromOrganisationActions.createOrganisation),
    switchMap((data) => this.organisation.createOrganisation(data)),
    map((response) => fromOrganisationActions.createOrganisationSuccess({ orgId: response.id })),
    catchError((error) => {
      this.store.dispatch(fromOrganisationActions.createOrganisationError(error));
      return throwError(error);
    })
  )
);

But other examples online suggest the first way should work, but it is not for me, and I do not understand why my stream never ends.

Can somebody please advise and tell me why my stream never ends in the first instance?

timdeschryver timdeschryver · Accepted Answer · 2021-06-11T12:11:20

The catchError should be added to the inner observable.

$createOrganisation = createEffect(() =>
  this.actions$.pipe(
    ofType(fromOrganisationActions.createOrganisation),
    switchMap((data) => this.organisation.createOrganisation(data).pipe (
      map((response) => 
        fromOrganisationActions.createOrganisationSuccess({ orgId: response.id })),
      catchError((error) => {
        return of(fromOrganisationActions.createOrganisationError(error));
      })
    )),
  )
);

These mistakes can be caught with eslint-plugin-ngrx, more details about the rule here.

ngrx effect - catchError: returning of does not end stream, and the API call does not re-run

1 Answers