如何在可观察对象中展平可观察对象数组 [英] How to flatten Array of Observables in an Observable

问题描述

我正在尝试展平嵌套的Observable，但我无法使其正常工作:

I'm trying to flatten a nested Observable, but I'm not getting it to work:

 this.af.object('test/father')
  .map(res => {
    res.namedKeys = [];
    for (let el in res.keys) {
      res.namedKeys.push(this.af.object(`test/keys/${el}`))
    }
    return res
  })
  .flatMap(res => Observable.combineLatest(res))
  .subscribe(res => {
    console.log('The final response:', res);
  });

我想获取数组中Observable的实际数据.在过去的两天里，我尝试了很多不同的方法，但是最后，我什么也没收到，或者仍然收到带有Observables的数组.上面的代码未返回任何内容.

I want to get the actual data of the Observables in my Array. I've tried a lot of different things the last 2 days, but in the end, I receive either nothing or still the Array with Observables in it. The code above is returning nothing.

推荐答案

由于您不提供任何结构信息，因此很难看出问题所在.

It's pretty hard to see what is the problem , since you don't supply any structure info.

我认为你的意思是:

 for (let el in Object.keys(res))

代替

 for (let el in res.keys) 

也- combineLatest 希望可以观察到.您没有提供一个:

Also - combineLatest expects an observable. you didn't supply one :

考虑改用它:

.flatMap(res => Rx.Observable.combineLatest(Rx.Observable.of(res)))

演示(使用rxjs 5使用switchmap而不是flatMap)
http://jsbin.com/cuvisecipi/1/edit?html，js，控制台，输出

Demo ( which uses rxjs 5 which uses switchmap instead of flatMap)
http://jsbin.com/cuvisecipi/1/edit?html,js,console,output

一个更好的演示，它演示了类似的(从数组中)解决方案:

A better demo which illustrates a similar ( from an array) solution :

http://jsbin.com/punoxitino/1/edit?html，js，控制台，输出

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