How to sort BehaviorSubject data?-CodePudding

I have replaced this.userrights to userrights$ observable:

public userrights$: Observable<UserRight[]>;

Before was a filter method is called from template by click event:

filterState(state: UserRightState) {
    this.userrights = this.clonned.filter((st: UserRight) => (this.filterBy == state ? true : st.value === getRightStateValue(state)));
    this.filterBy = this.filterBy == state ? null : state;
}

How to rewrite it on RXJS?

I have createed a new subject that contains filter state public state$ = new Subject<UserRightState >().

How to filter BehaviorSubject data and return back?

CodePudding user response：

If you have both filterBy and the list you want to filter in two Observables you can use combineLatest():

filterBy$ = new BehaviorSubject<UserRightState | null>(null);
allUserRights$ = new BehaviorSubject<UserRight[]>([]);

userrights$ = combineLatest([
  filterBy$.pipe(
    pairwise(),
    map(([prevState, state]) => prevState === state ? null : state),
  ), // This will take care of toggling filterBy.
  allUserRights$,
]).pipe(
  map(([filterBy, userRights]) => userRights.filter(/* do whatever with `filterBy` */))
)

filterState(state: UserRightState) {
  filterBy$.next(state);
}

If you know that this.clonned will never change you can remove combineLatest of course.

CodePudding user response：

You can map the observable to another observable:

const filteredRights$ = userrights$.pipe(
 map(rights => rights.filter(rights => // whatever condition))
);