Why does finally() not work after catching on an Observable in Angular 2?

Question

I am trying to add a loading spinner to every request that ends in Angular 2, so I extended the Http service calling it HttpService. After every request I would like to call a finally() function after catching errors so that I can stop the loading spinner.

But typescript says:

[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()}`);
        }        
    }
}

How can I run some code after every http request like this? What is the best way of doing it?

Answer 1

You forgot to import it:

import 'rxjs/add/operator/finally';

Answer 2

Heads up, future readers:

since angular 6, that introduced rxjs version 6.0, we now use finalize instead of finally.

It's now used within a pipe, so

observable.finally( x => console.log(x)).subscribe()

is now

observable().pipe( finalize( x => console.log(x))).subscribe()

and you import it from rxjs/operators

import { finalize } from 'rxjs/operators'