How to change value in object in array BehaviorSubject?

Question

I have a initial data as: const menuItems = [{id: 1, active: false}, {id: 2, active: false}]

  public menuSubject$ = new BehaviorSubject<MenuItem[]>(menuItems);
  public menu$ = this.menuSubject$.asObservable();

I try to modify element where id: 1:

modify(id: number) {
   const menuItemsUpdated = this.menuSubject$.getValue().map((item) => {
      if(item.id === id) {
         return {...item, active: true};
      }
      return item;
   });

    this.menuSubject$.next(menuItemsUpdated);
}

I wonder is it properly way to do that using async getValue() and pushing this back?

it is fine. more rxjs way would be to create updates$ and merge it with the original stream to build the resulting value, but in your particular sutuation it woul just be a more comlicated way of solving the same problem — Andrei, Feb 19 '21 at 14:52
it is not modifying all of the items. why did you think it does? — Andrei, Feb 19 '21 at 15:24
This is a good question and I asked pretty much the thing a few months back ["RXJS - BehaviorSubject: proper use of .value"](https://stackoverflow.com/questions/62262008/rxjs-behaviorsubject-proper-use-of-value). You may find some of the answers interesting. — BizzyBob, Feb 19 '21 at 16:05

score -1 · Accepted Answer · answered Feb 19 '21 at 14:40

-1

Seems ok. I would do the same thing .

answered Feb 19 '21 at 14:40

Utukku

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The template is blinking when whole object re-rendered. That is disandvantage – Feb 19 '21 at 15:43

How to change value in object in array BehaviorSubject?

1 Answers1