Rxjs callback on every success/error call - rxjs

Question

I have a scenario like this,
this.uiDataObservable.pipe(
tap(() => this.showLoader.next(true)),
map((uiData) => this.createHttpRequest(uiData),
switchMap((httpRequest) => this.apiService.get(httpRequest),
map((response) => this.createUISucessData(response),
)
).subscribe(
(success) => /* show data on UI */,
(error) => /* show error on UI */,
);
Now in this example what is the right place to call this.showLoader.next(false).
I cannot use finalize because my stream never ends.
I cannot use the third callback complete of subscribe block as it never
gets calls on error.
What is the correct rxjs way of handling this situation?

Answer 1

Adding it to success and error callback is something not I am looking for here. I am expecting something more rxjs way. - OP
I'm not sure why using RxJS callbacks should be considered less RxJS than anything else. Regardless, in an effort to not repeat this.showLoader.next(false), you could create a custom operator that handles the calls for you.
That might look as follows:
function tapNxtErr<T>(fn: () => void): MonoTypeOperatorFunction<T> {
return tap({
next: _ => fn(),
error: _ => fn()
});
}
this.uiDataObservable.pipe(
tap(() => this.showLoader.next(true)),
map(uiData => this.createHttpRequest(uiData)),
switchMap(httpRequest => this.apiService.get(httpRequest)),
map(response => this.createUISucessData(response))
tapNxtErr(() => this.showLoader.next(false))
).subscribe({
next: success => /* show data on UI */,
error: error => /* show error on UI */
});

Answer 2

Found better alternative, code goes like this:
this.uiDataObservable.pipe(
tap(() => this.showLoader.next(true)),
map((uiData) => this.createHttpRequest(uiData),
switchMap((httpRequest) => {
return this.apiService.get(httpRequest).pipe(
catchError((error) => {
/* show error on UI */
return of({ /* return empty response or undefined */ })
})
)
},
map((response) => this.createUISucessData(response),
)
).subscribe(
(data) => {
this.showLoader.next(false);
/* show data on UI */,
});