管道操作员时如何返回可观察到的"forkJoin" [英] How to return a `forkJoin` observable when piping the operators

问题描述

在我使用此解析器之前，它工作得很好:

Before I had this resolver that just worked fine:

resolve() {
    return forkJoin(
        this.getData1(),
        this.getData2(),
        this.getData3()
    );
}

现在我必须做一些实际上是行不通的事情:

Now I have to do something like that which is actually does not work:

  resolve() {
    return this.actions$
      .pipe(
        ofActionSuccessful(SomeSctonSuccess),
        forkJoin(
           this.getData1(),
           this.getData2(),
           this.getData3()
        )
      );
    }

当我遇到此错误时:

'Observable< [任何，任何，任何，任何]>类型的参数不可分配 到"OperatorFunction"类型的参数.类型 'Observable< [[任何，任何，任何，任何]>'不提供签名的匹配项 (来源:可观察):可观察".

Argument of type 'Observable<[any, any, any, any]>' is not assignable to parameter of type 'OperatorFunction'. Type 'Observable<[any, any, any, any]>' provides no match for the signature '(source: Observable): Observable'.

任何想法如何解决?

现在，我只在ofActionSuccessful(SomeSctonSuccess)发生后才注意返回我的forkJoin https ://ngxs.gitbook.io/ngxs/advanced/action-handlers

Now I heed to return my forkJoin only after ofActionSuccessful(SomeSctonSuccess) is taking place https://ngxs.gitbook.io/ngxs/advanced/action-handlers

推荐答案

使用exhaustMap运算符.它映射到内部可观察的对象，忽略其他值，直到该可观察的对象完成

Use exhaustMap operator. It maps to inner observable, ignore other values until that observable completes

import { forkJoin } from 'rxjs';
import { exhaustMap } from 'rxjs/operators';

resolve() {
    return this.actions$
      .pipe(
        ofActionSuccessful(SomeSctonSuccess),
        exhaustMap(() => {
         return forkJoin(
             this.getData1(),
             this.getData2(),
             this.getData3()
           )
       })

      );
    }

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