Angular HTTP拦截器如何链接一个可观察的

Question

我正在使用 Azure AD adal 库进行身份验证。有一个调用来获取返回可观察对象的 token 。如何将此可观察值添加到拦截中？在下面的示例中，我如何才能将订阅中设置的请求作为 Observable 返回？

  intercept(request: HttpRequest<any>, next: HttpHandler): Observable<HttpEvent<any>> {
    this.authAzureService.getAccessToken()
    .subscribe(token => {
      // I need this to be returned
      request = this.getRequestWithHeaders(request, token);
    });

    // This returns the request before the access token is added
    return next.handle(request);
  }

Answer 1

感谢@Commecial Suicide，我找到了解决方案，即使用平面 map 。这是有效的代码:

  intercept(request: HttpRequest<any>, next: HttpHandler): Observable<HttpEvent<any>> {
    let requestHandler = this.authAzureService.getAccessToken()
    .flatMap(token => {
      request = this.getRequestWithHeaders(request, token);
      return next.handle(request);
    });
    return requestHandler;
  }