angular - 为什么 finally() 在捕捉到 Angular 2 中的 Observable 后不起作用？

Question

我正在尝试为以 Angular 2 结尾的每个请求添加一个加载微调器，因此我扩展了 Http 服务，将其称为 HttpService。在每个请求之后，我想在捕获错误后调用 finally() 函数，以便我可以停止加载微调器。

但是 typescript 说:

[ts] Property 'finally' does not exist on type 'Observable'.

import { AuthService } from './../../auth/auth.service';
import { Injectable } from '@angular/core';
import { Http, XHRBackend, RequestOptions, RequestOptionsArgs, Request, Response, Headers } from '@angular/http';

import { Observable } from 'rxjs/Observable';
import 'rxjs/add/operator/catch';
import 'rxjs/add/observable/throw';

@Injectable()
export class HttpService extends Http {

    constructor(
        backend: XHRBackend,
        options: RequestOptions,
        private authservice: AuthService
    ) {
        super(backend, options);
        this.updateHeaders(options.headers);
    }

    request(url: string|Request, options?: RequestOptionsArgs): Observable<Response> {
        return super.request(url, options)
            .catch((response: Response) => this.authError(response))
            .finally(() => {
                // ...
                /* Do something here when request is done. For example
                finish a spinning loader. */
            });
    }

    private authError(response: Response) {
        if (response.status === 401 || response.status === 403) {
            this.authservice.logout();
        }
        return Observable.throw(response);
    }

    private updateHeaders(headers: Headers) {
        headers.set('Content-Type', 'application/json');
        if (this.authservice.isloggedIn()) {
            headers.set('Authorization', `Bearer ${this.authservice.getToken()}`);
        }        
    }
}

如何在每次这样的 http 请求后运行一些代码？最好的方法是什么？

Answer 1

你忘了导入它:

import 'rxjs/add/operator/finally';