I have a Subject of Array of Users
private _currentHeroes = new Subject<Hero[]>();
currentHeroes = this._currentHeroes.asObservable();
Function of power up the user in my service
powerUp(id: number) {
return this.http
.post<Hero>(environment.apiUrl + 'heroes/powerUp/' + id, {})
.pipe(
tap((updatedHero: Hero) => {
this._currentHeroes.next(
// I would like to edit the specific element in the array and than sort them by the power.
);
})
);
}
Function of delete the user in my service
delete(id: number) {
return this.http.delete<Hero>(environment.apiUrl + 'heroes/' + id).pipe(
tap((deletedHero) => {
this._currentHeroes.next(
// Here I delete the specific element from the array
);
})
);
}
If the Subject was BehaviorSubject so I would do this:
powerUp(id: number) {
return this.http
.post<Hero>(environment.apiUrl + 'heroes/powerUp/' + id, {})
.pipe(
tap((updatedHero: Hero) => {
this._currentHeroes.next(
this._currentHeroes.value
.map((hero: Hero) =>
hero.id === updatedHero.id ? updatedHero : hero
)
.sort((a, b) => a.currentPower - b.currentPower)
);
})
);
}
delete(id: number) {
return this.http.delete<Hero>(environment.apiUrl + 'heroes/' + id).pipe(
tap((deletedHero) => {
this._currentHeroes.next(
this._currentHeroes.value.filter(
(hero: Hero) => hero.id !== deletedHero.id
)
);
})
);
}
But my goal is to achieve the same while using Subject instead of BehaviorSubject.
I tried getting the value of the subject but it's not possible since it's a Subject. I tried searching online but unfortunately, I didn't find any useful solution for my needs.
Does anyone encounter this issue? Or how to fix it?
I suppose you are working on a service, then you can have a reference of array you need to modify in service attr.
heroes = [];
then, after every operation, you can modify that values and then emit with Subject or Behavior Subject or whatever you want to use.
powerUp(id: number) {
return this.http
.post<Hero>(environment.apiUrl + 'heroes/powerUp/' + id, {})
.pipe(
tap((updatedHero: Hero) => {
//modify data reference, to add, update or delete value
// in this case modify with powerup
this.heroes = this.heroes
.map((hero: Hero) =>
hero.id === updatedHero.id ? updatedHero : hero
)
.sort((a, b) => a.currentPower - b.currentPower)
// emit the resuelt after every operation
this._currentHeroes.next(
this.herores
);
})
);
}
Remember you have to subscribe to every operation that return an observable like you show in your code.
// for example to hero with id 2
this.yourHeroService.powerUp(2).subscribe()