How to implement behavior subject using service in Angular 8

Question

I\'m new to Angular and I\'m having an issue.

I\'m creating an app with several sibling components. When I update a value in one component other components don\'t u

Answer 1

There are a few ways to do that. One of them is described here.

1) Build your service like this:

// ReplaySubject is more flexible than BehaviorSubject, as it
// allows you to define how many past emissions should be available.
// But you can get an equivalent code with BehaviorSubject by
// coding like this:
// private _coachProfile$: BehaviorSubject = 
//    new BehaviorSubject(null);
private _coachProfile$: ReplaySubject = new ReplaySubject(1);

coachProfile(token :string)
{  
  return this.http.post(this.apiURL+'/coach/profile_infos',{
    token: token,
  }).subscribe((profile) => this._coachProfile$.next(profile));        
}

subscribeToGetCoachProfile$()
{  
  return this._coachProfile$.asObservable();       
}

2) And in your components:

ngOnInit() {
  this.coachService.subscribeToGetCoachProfile$()
    .subscribe((profile) => this.coachProfile = profile);
}

Well there are other approaches you can think of, but I think this is the simpler one given the sample code you pasted on your question.

As a side note: if you do some search on stackoverflow, you'll see that this question (or similar questions) has been asked many times here. Take a look, for example in this other approach: Multiple subscriptions without recalculate common part