我有一系列方法,这些方法取决于其他方法的完成。

process1(data: string) : Observable<string> {
   this.dataservice.process(data).subscribe(
            (response) => {
                return response.data;
            }
        );
}

main(data: string) : string {

   var process1Data: string = process1(data);

   // I would like to wait for process1 method to complete before running process2
   // I do not want to include process2 inside subscribe of process1 because I have to make few more method calls
   var process2Data: string = process2(process1Data);

   var process3Data: string = process3(process2Data);

   ...

}

如何在调用下一个方法(process2,process3)之前等待可观察对象完成? (类似于C#中的await)

最佳答案

您可以尝试这样的事情...

main(data: string) : string {

    process1Data$: Observable<string> = process1(data)
        .take(1)
        .switchMap((process1Data) => return process2(process1Data);
    .
    .
    .
}

显然,take(1)假定process1(...)解析为单个值并停止。之后,将switchMap转换为process2,这意味着它将开始发出process2给出的可观察值。
另一方面,如果您希望对process2发出的每个结果运行process1,则只需删除take(1)即可。

关于javascript - 等待观察完成,我们在Stack Overflow上找到一个类似的问题:https://stackoverflow.com/questions/45354940/

10-13 06:03