Question

private getScmServiceMeta(serviceId: string): Observable<any> {
    let service = this.getServiceItem(serviceId);

    if (service) {
        return this.httpClient.get(serviceUri).map((res: Response) => {
                return _.get(res, 'data.serviceinfo');
            })
    } else {
        return Observable.throw('backend server error');
    }
}

public inquireScmData(serviceId: string, params: object, templateId: string): Observable<any> {
    return this.getScmServiceMeta(serviceId).map((serviceInfo: any) => {

        let uri = serviceInfo.routeTemplate;

        // How to return the _.get(res, 'data') as an Observable ???
        return this.httpClient.get(uri).map((res: Response) => {
            if (_.startsWith(_.get(res, 'status.code'), '200')) {
                return _.get(res, 'data');
            } else {
                throw ('status code error');
            }
        })
    })
}

作为上面的代码，我需要在调用函数'inquireScmData'时返回一个observable，但是在函数内部，它需要调用另一个函数'getScmServiceMeta'，这也是异步的并且还返回一个Observable，所以如何返回'_.get（res，'data'）'作为Observable ??? 感谢

Answer 1

rxjs为Observable提供了一个静态方法来执行此操作。

Observable.of( _.get(res, 'data') );

但是，您将拥有Observable<Observable<Observable<any>>>。这是你想要的，或者你只是想链接“异步”操作。如果是这样，您应该按原样保留代码，并使用mergeMap。

public inquireScmData(serviceId: string, params: object, templateId: string): Observable<any> {
  return this.getScmServiceMeta(serviceId).mergMap((serviceInfo: any) => {

    let uri = serviceInfo.routeTemplate;

    return this.httpClient.get(uri).map((res: Response) => {
      if (_.startsWith(_.get(res, 'status.code'), '200')) {
        return _.get(res, 'data');
      } else {
        throw ('status code error');
      }
    })
  })
}

angular httpclient返回一个Observable

1 个答案: