Question

我在Angular 2中创建了一个HTTP拦截器。拦截器的代码如下导出类HttpInterceptor扩展了Http {

  private httpSubject = new Subject<Message>();
  httpSubject$ = this.httpSubject.asObservable();
  private block : boolean = true;

    constructor(backend: ConnectionBackend, defaultOptions: RequestOptions, private _router: Router, private dataSharingService : DataSharingService) {
        super(backend, defaultOptions);
    }

    post(url: string, body: any, options?: RequestOptionsArgs): Observable<Response> { 
        this.dataSharingService.beforeRequest.emit("beforeRequestEvent"); 
        return this.intercept(super.post(url, body, this.getRequestOptionArgs(options)));
        //return super.post(url, body, this.getRequestOptionArgs(options));
    }

    put(url: string, body: any, options?: RequestOptionsArgs): Observable<Response> {
        this.dataSharingService.beforeRequest.emit("beforeRequestEvent");
        return this.intercept(super.put(url, body, this.getRequestOptionArgs(options)));
    }



    getRequestOptionArgs(options?: RequestOptionsArgs) : RequestOptionsArgs {
        if (options == null) {
            options = new RequestOptions();
        }
        if (options.headers == null) {
            options.headers = new Headers();
        }
        //options.headers.append('Content-Type', 'application/json');
        return options;
    }


    intercept(observable: Observable<Response>): Observable<Response> {

      observable.subscribe(
            null, 
            error =>  this.dataSharingService.afterRequest.emit("afterRequestEvent"),                               
            () => this.dataSharingService.afterRequest.emit("afterRequestEvent")            
          ); 


          return observable;       

    }
}

在拦截函数中，如果注册了错误回调，则浏览器会发出两次相同的http请求，并且当删除错误回调时，不会触发事件（这需要隐藏加载指示符）。

错误回叫我的意思是这一行

error =>  this.dataSharingService.afterRequest.emit("afterRequestEvent")

在拦截方法中。

Answer 1

似乎主题多次注册subscribe（）。一旦通过observable的响应返回，你能尝试取消订阅observable吗？否则，您可以在每次intercept（）调用期间更简单地创建新的observable，并返回它以避免多个回调被注册。

在RxJS Observable上注册onError回调，导致在Angular 2中发送两次相同的http请求

1 个答案: