CombineLatest returns 错误值

Question

我意识到订阅 returns 一个错误的值

// in ts file of a component
combineLatest([this.editSrv.getOrders(), this.route.queryParams]).subscribe(data => {
    this.orders = data[0];
    ...
})

和

// in editSrv
 getOrders(){
    // orders$: BehaviourSubject
    if(this.orders$.getValue().length > 0){
      // ordersSource = this.orders$.asObservable()
      return this.ordersSource$;
    }
    return this.http.get<any[]>("retrieve orders from api").pipe(
      map(orders => {
        this.orders$.next(orders);
        return orders;
      })
    )
  }

当我现在删除组件中具有以下功能的订单时

removeOrder(order){
    let foundOrder = this.orders.find(o => o.id == order.id);
    if(foundOrder){
        const index = this.orders.indexOf(foundOrder);
        this.orders.splice(index,1);
    }
}

并用这个函数改变当前路线的queryParams

cancel(){
    this.router.navigate([]); 
}

上面的 combineLatest 被触发但是 this.editSrv.getOrders() returns orders 没有删除订单虽然我没有调用 next 但是为什么 getOrders() returns 现在除了我在组件中删除的订单之外的所有订单都没有调用 next？不应该保持原样吗？

Answer 1

我认为你需要做 this.orders$.next(foundOrder);删除项目后；

if(foundOrder){
    const index = this.orders.indexOf(foundOrder);
    this.orders.splice(index,1);
    this.orders$.next(foundOrder);
}

然后我相信您将不再需要 combineLatest

CombineLatest returns 错误值

CombineLatest returns wrong value

rxjs

typescript

angular

combinelatest