Angular HttpClient 可观察未完成

Question

我有以下代码：

// in a service
downloadCSV(): Observable<Blob> {
  return this.httpClient.get(`${apiUrl}/a.csv`, {responseType: 'blob'});
}
// in component
onDownloadClicked(event: MouseEvent) {
  this.downloading = true;
  this.service.downloadCSV()
    .pipe(finalize(() => this.downloading = false))
    .subscribe(
      (data: Blob) => {
        console.log(data);
      },
      (error) => {
        console.error(error);
        alert('Sorry, something wet wrong. Try again.');
      },
      () => {
        console.log('completed!');
      }
    );
}

数据已正确记录，但 'completed!' 未记录且从未调用 finalize。

编辑：

所以在进一步调查中，问题似乎与添加身份验证的拦截器有关 header。

如果拦截器被绕过（并在服务器上禁用身份验证），则可观察对象将无错误地完成。

我不明白为什么会这样。可能与克隆请求有关？

//interceptor code
intercept(req: HttpRequest<any>, next: HttpHandler): Observable<HttpEvent<any>> {
  let scope: string;
  // only inject tokens for the following scopes
  if (req.url.indexOf('https://graph.microsoft.com') === 0) {
    scope = 'https://graph.microsoft.com';
  }
  else if (req.url.indexOf('https://management.azure.com') === 0) {
    scope = 'https://management.azure.com';
  }
  else if (req.url.indexOf(environment.apiUrl) === 0) {
    scope = environment.appId;
  }
  if (scope) {
    return this.authService.getToken(scope).pipe(
      switchMap((token) => {
        let newReq;
        if (token) {
          const JWT = `Bearer ${token}`;
          newReq = req.clone({
            setHeaders: {
              Authorization: JWT,
            }
          });
        }
        return next.handle(newReq || req);
      })
    );
  }
  else {
    return next.handle(req);
  }
}

Answer 1

原来问题出在我的授权服务的getToken函数中。我忘记在返回令牌后完成可观察的！由于 httpClient.get observable 是通过我的 getToken observable 切换映射的，这导致我在 onDownloadClicked 中的订阅永远无法完成。

// from my auth service
getToken(resource: string): Observable<string> {
  return Observable.create((observer: Observer<string>) => {
    this.context.acquireToken(resource, (error, token) => {
      if (token) {
        observer.next(token);
        observer.complete(); // this was missing
      }
      else {
        this.login();
      }
    });
  });
}

Angular HttpClient 可观察未完成

Angular HttpClient observable not completing

javascript

observable

rxjs

angular

angular-httpclient