从内部 flatMap 通知 [英] Notify from inner flatMap

问题描述

这是一个相当复杂的示例:

Here a quite complex sample:

主要内容:

this.runInstructionAndGetResult().subscribe({
      next: val => console.log(`NEXT VALUE: ${val}`),
      error: val => console.log(`ERROR VALUE: ${val}`),
      complete: val => console.log(`COMPLETE`)
    });

可观察的:

public runInstructionAndGetResult(): Observable<string> {
    return this.runAnInstruction()
        .flatMap((data) => {
            console.info("flatMap of runAnInstruction:", data);
            return this.getInstructionExecutionStatusInPolling()
                .filter(data => data != "Polling")
                .take(1)
                .flatMap((data) => {
                    console.info("flatMap of getInstructionExecutionStatusInPolling:", data);
                    return this.getInstructionResult();
                }).map((data) => {
                    console.info("Map of getInstructionResult:", data);
                    return data;
                });
        });
  }

  public runAnInstruction(): Observable<string> {
    return Observable.of("StartRun");
  }

  public getInstructionResult(): Observable<string> {
    return Observable.of("FinalResult");
  }

  public getInstructionExecutionStatusInPolling(): Observable<string> {
    return Observable.interval(1000)
        .concatMap(data => {
            return this.getInstructionExecutionStatus();
        });
  }

  public getInstructionExecutionStatus(): Observable<string> {
    return Observable.of("Polling", "Terminate");
  }

这里是:https://plnkr.co/edit/c1cahMtVARQnLgnHWlEe?p=preview

主要问题是我只想得到关于内部流外部进化"的通知.

Main problem is that i just would like to be notify about "evolution" of inner stream outside.

现在只有当所有内部 flatMap 都完成时，我们才在 main 上有next"事件.

如何获得通知?例如在轮询期间，我如何向主流发出显式值?

How to get notify? How can i emit explicit values to main stream for example during polling?

谢谢.

推荐答案

我找到了一个解决方案来分享.

I found a solution to share.

这里plunker更新:

Here plunker updated:

https://plnkr.co/edit/c1cahMtVARQnLgnHWlEe?p=preview

基本上我使用以下方法创建一个简单的可观察对象:https://github.com/Reactive-Extensions/RxJS/blob/master/doc/api/core/operators/create.md

Basically i create a simple observable using : https://github.com/Reactive-Extensions/RxJS/blob/master/doc/api/core/operators/create.md

然后我以编程方式调用 next 方法并最终完成:

then i call programmatically next method and complete finally:

 public runInstructionAndGetResult(): Observable<string> {
    return Observable.create((ops)=> {
      ops.next(1);
      this.runAnInstruction()
        .concatMap((data) => {
            ops.next(2);
            console.info("flatMap of runAnInstruction:", data);
            return this.getInstructionExecutionStatusInPolling()
                .filter(data => data != "Polling")
                .take(1)
                .concatMap((data) => {
                    ops.next(3);
                    console.info("flatMap of getInstructionExecutionStatusInPolling:", data);
                    return this.getInstructionResult();
                }).map((data) => {
                    console.info("Map of getInstructionResult:", data);
                    ops.next(4);
                    ops.complete();
                    return data;
                });
        }).subscribe();
        });
  }

这篇关于从内部 flatMap 通知的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！