Question

请查看以下尝试，以更好地理解：

this.loading = true;
obs.pipe(
   finalize(() => this.loading = false) //If set to false here and the person has children then there will be another request and the requests are not over yet
).subscribe(person => {
    if(person && person.children){
       obs2.pipe(
          finalize(() => this.loading = false) //If only set to false here and the person has no children then the false property will never actually be set to false
       ).subscribe(children => {
          //Do stuff with response
       })
    }
})

我的目标是在请求结束时将loading属性设置为false。

我希望已经很好地解释了我的问题。预先感谢。

Answer 1

您应该使用switchMap运算符将两个可观察值合并为一个：

this.loading = true;
loadParent().pipe(
  switchMap(parent => {
    if (person.children) {
      return loadChildrenOf(parent).pipe(
        map(children => ({ parent, children })
      )
    } else {
      return of({parent, children: [] })
    }
  }),
  finalize(() => this.loading = false)
).subscribe(({ parent, children }) => {
  // Do stuff with the parent and its children
});

如何完成嵌套的Observables？

1 个答案: