Example

book.ts

@Component({})
export class BookComponent {
	private readonly bookService = inject(BookService);

	protected readonly $isLoading = signal(false);

	readonly bookId = input.required<string>();

	protected readonly $bookDetails = toSignal(
		toObservable(this.bookId).pipe(
			switchMap((id) => {
				if (!id) {
					return EMPTY;
				}
				this.$isLoading.set(true);
				return this.bookService.getBookDetails(id).pipe(
					finalize(() => this.$isLoading.set(false)),
					catchError((err) => {
						console?.error(err);
						return EMPTY;
					})
				);
			})
		)
	);
}