拦截错误并订阅

Question

我遇到了以正确方式订阅我的http拦截器的问题。我有以下几点：

post(url: string, body: any, options?: RequestOptionsArgs): Observable<Response>{ 
    return super.post(url,body, {headers: customHeaders}).catch(err =>{ 
      console.log('Error caught in POST at '+url); 
      return Observable.of(err); 
     }); 
    } 

这是好的 - 它记录每次发布时发生错误。但是，如果我试图抓住错误在其他组件是这样的：

this.http.post('someurl','somestring') 
    .subscribe(
     success=>{ 
      console.log('success: ',success); 
     }, 
     error=>{ 
      console.log('error: ',error); 
     } 
    ) 

所以现在，当在POST的错误我的控制台日志打印：

Error caught in POST at someurl 
success: //errorobject here// 

不过，我期待这样的：

Error caught in POST at someurl 
error: //errorobject here// 

我在做什么错？

Answer 1

我觉得应该是throw err而不是Observable.of(err)

post(url: string, body: any, options?: RequestOptionsArgs): Observable<Response>{ 
    return super.post(url,body, {headers: customHeaders}).catch(err =>{ 
      console.log('Error caught in POST at '+url); 
      throw err; 
     }); 
    } 

Answer 2

我会用Observable.throw，而不是Observable.of：

post(url: string, body: any, options?: RequestOptionsArgs): Observable<Response>{ 
    return super.post(url,body, {headers: customHeaders}).catch(err =>{ 
     console.log('Error caught in POST at '+url); 
     return Observable.throw(err); // <-------------- 
    }); 
} 

Observable.of返回一个“成功”可观察则其将被成功处理在subscribe内回调。