rxjs storage

store.ts

class UserStorage {
    private readonly reload$ = new Subject<void>();
    private readonly userId$ = new ReplaySubject<number>(1);
    public readonly user: Observable<string>;
    constructor() {
        this.user = combineLatest([
            this.reload$.pipe(startWith(undefined)),
            this.userId$
        ]).pipe(
            switchMap(([_, userId]) => this.loadUser(userId)),
            shareReplay({ bufferSize: 1, refCount: true }),
        );
    }
    public load(userId: number) {
        this.userId$.next(userId);
    }
    public reload(): void {
        this.reload$.next();
    }
    private loadUser(userId: number): Observable<string> {
        return of(`user loaded with ${userId}`).pipe(tap(() => console.log('loading...')))
    }
}

const userStorage = new UserStorage();

userStorage.load(1);

userStorage.user.subscribe(x => {
    console.log(`1: `, x);
});

userStorage.user.subscribe(x => {
    console.log(`2: `, x);
});

// userStorage.load(2);

// setTimeout(() => {
//     userStorage.reload();
//     userStorage.reload();
//     userStorage.reload();
// }, 700)