Angular 2 RxJS Observable: RetryWhen filter retry on error Status

Question

I am using Angular 2 HTTP library which returns an observable. I want to implement retry on certain error status/code.

I have an issue, if the error is not 429,

Answer 1

A little late to the party but, I recently implemented a similar behaviour. Here is my solution:

  post<T>(serviceUrl: string, data: any): Observable<T> {
    return Observable.defer(() => {
        return super.post<T>(serviceUrl, data);
    }).retryWhen((error) => {
        return this.refresh(error);
    });
}

And the refresh function:

refresh(obs: Observable<any>): Observable<any> {
    return obs
        .switchMap((x: any) => {
            if (x.status === 401) {
                return Observable.of(x);
            }
            return Observable.throw(x);
        })
        .scan((acc, value) => {
            return acc + 1;
        }, 0)
        .takeWhile(acc => acc < 3)
        .flatMap(() => {
            console.log('Token refresh retry');
            return this.tokenRefreshService.refreshToken();
        });
}

The use case is that whenever I make an HTTP request and get a 401 response, I want to do a token refresh and then retry the initial request with the new token. When a 401 occurs I use switchMap to return a new Observable, otherwise, I return an Observable.throw(x) that stops the retry logic from being executed.

And the calling code looks like this (where error is called whenever you return an Observable.throw(x)):

 this.http.post(x).subscribe(response => {
      ...
        }
    }, error => {
        ...
        }
    });