Exploring the functionalities of Firebase's FirebaseListObservable alongside the powerful

How can I create an observable that depends on the value of another observable? It seems simple, but I can't figure out how to do it.

user$: Observable<firebase.User>;
playlists$: FirebaseListObservable<any>;

constructor(db: AngularFireDatabase,
          private afAuth: AngularFireAuth) {
    this.user$ = afAuth.authState;
    // encountering an error here
    this.playlists$ = this.user$.flatMap(user => db.list(`/playlists/${user.uid}`));
}

The issue at hand is: 'Observable' cannot be assigned to type 'FirebaseListObservable'. The property `$ref` is missing in the 'Observable' type.

Answer №1

Make sure to update the annotation from

playlists$: FirebaseListObservable<any>;
to
playlists$: Observable<any>;
.

When working with flatMap, it is important to note that the type annotation you should use when storing the result in a variable is Observable<any>.

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