Can I create an instance of a service for every loaded component in Angular?

Question

I have a component named edit-order.component with the following ts file

export class EditOrderComponent implements OnInit {

  constructor(private editOrderSrv: EditOrderService, private route: ActivatedRoute) { }

  ngOnInit(): void {
    this.editOrderSrv.getOrderById(this.route.snapshot.params.id);
  }
}

and in my edit-order-service.service.ts I have the following code

export class EditOrderService {
  order$: BehaviorSubject<any> = new BehaviorSubject(null);
  constructor(private http: HttpClient) { }

  getOrderById(id: string){
    this.http.get('url', {params: {id}}).subscribe(order => {
      this.order$.next(order);
    }, error => {console.error(error)});
  }
}

The client should be able to open more than one edit-order.component with different id. In my child.component I want to subscribe to order$ like that

export class ChildComponent implements OnInit {
  order: any;
  constructor(private editOrderSrv: EditOrderService) { }

  ngOnInit(): void {
    this.editOrderSrv.order$.subscribe(order => {
      if(order) this.order = order;
    })
  }

}

But therefore I have to have own instances of the service for every edit-order.component to not overwrite order$. How would I achieve that? Or is this not possible? And if it is not possible, what can I do else to achieve my goal?

Answer 1

Curiosity, why not your function is

getOrderById(id: string){
    return this.http.get('url', {params: {id}})
  }

And you subscribe to getOrderById?

You can pipe(catchError) if you wish

Update you can also use a "cache" in the service without use an array of Subject, only an array of object

  orders:any={}  //create an empty object where we store the result

  getOrderById(id: string){
    if (this.orders[id])
        return of(this.orders[id]

    return this.http.get('url', {params: {id}}).pipe(
      tap(res=>{
         this.orders[id]=res;
      })
    )
  }