javascript - RxJS:解开嵌套的可观察对象

我正在寻找一种比我现有的解决方案更具可读性的解决方案。

我需要：
1）从API检索产品。它们是objs数组。
2）根据类别等过滤那些产品...
3）对产品进行分页并返回这些产品的分页版本。

ngOnInit() {

//This gets the products from the API
    this.drinkSubscription = this.drinkService.getAllDrinks().subscribe(drinks => {

//Save products without pagination for other purposes
      this.allDrinks = drinks;

//Get the parameter to filter products
      this.paramSubscription =  this.route.params.subscribe((params: Params) => {

//Filter the products and return a filtered array
        const filteredDrinks = this.filterService.filter(drinks, params['filter'], params['name']);

//Sort products based on the selection
        this.sorterSubscription = this.sorter.initialize(filteredDrinks).subscribe(sortedDrinks => {

//Create a pager that holds the paginated drinks in a property
          this.pagerSubscription = this.pagerService.initializePaginatedItems(sortedDrinks, 10, 5)
                                  .subscribe(pager => {
                                    this.pager = pager;
                                    this.paginatedDrinks = pager.paginatedItems;
                                  });
        });
      });
    });
  }

排序器和分页是BehaviorSubjects，因此我可以注入next（），但我对它们并不满意...
您可以看到缩进的级别很高，我想知道RxJS是否有一种方法可以更可读地获得相同的结果。

最佳答案

您应该能够使用运算符将​​它们组合在一起。我相信以下应该可行。

CombineLatest大致类似于Promise.all([p1,p2])-仅当任何可观察对象发射时使用其他值使用之前的值发射。

switchMap允许您获取一个可观察对象发出的值，并将其映射到另一个可观察对象。

https://www.learnrxjs.io/operators/combination/combinelatest.html
https://www.learnrxjs.io/operators/transformation/switchmap.html

例如：

let drinkObservable = this.drinkService.getAllDrinks()
let paramsObervable = this.route.params

let sub = combineLatest(drinkObservable, paramsObervable)
  .pipe(switchMap(([drinks, params]) => {
    this.allDrinks = drinks
    let filteredDrinks = this.filterService.filter(drinks, params['filter'], params['name']);
    return this.sorter.initialize(filteredDrinks)
  }))
  .pipe(switchMap(sortedDrinks => {
    return this.pagerService.initializePaginatedItems(sortedDrinks, 10, 5)
  }))
  .subscribe(pager => {
    this.pager = pager;
    this.paginatedDrinks = pager.paginatedItems;
  })

关于javascript - RxJS:解开嵌套的可观察对象，我们在Stack Overflow上找到一个类似的问题：https://stackoverflow.com/questions/52408401/