Angular HttpInterceptor modifies the error object

Question

I've implemented an HttpInterceptor that adds a header to each requests and redirects to the login page if server responded with 401 . I don't want it to do anything else.

I'm noticing however that whenever I get a bad response from the server (as I expect it), the interceptor kicks it and throws the HttpErrorResponse . However in my controller I get only a TypeError object without the details from the server.

I'm attaching the relevant code.

Interceptor

@Injectable()
export class HttpAuthorizationService implements HttpInterceptor {

  constructor(private cookieService: CookieService, private angularRouter: Router) { }

  intercept(req: HttpRequest<any>, next: HttpHandler):  Observable<HttpEvent<any>> {
    req = req.clone({
      setHeaders: {
        Authorization: 'Bearer ' + this.cookieService.get('Authorization')
      }
    });

    return next.handle(req).do((ev: HttpEvent<any>) => {})
    .catch(error => {
      if (error instanceof HttpErrorResponse) {
        if (error.status === 401) {
          this.cookieService.set('expired', 'Session expired');
          this.angularRouter.navigate(['/login']);
        }
      }
      return Observable.throw(error); <-- i think this is bad
    });
  }
}

and actual controller

deleteCategory(category) {
this.confirmationService.confirm({
  message: 'Are you sure you want to delete?',
  header: 'Delete product category ' + category,
  icon: 'fa fa-trash',
  accept: () => {
    this.productService.deleteCategory(category).subscribe(
      success => {
        this.msgs = [{ severity: 'success', summary: 'Success', detail: 'Successfully deleted the product category ' + category }];
      },
      error => {
        this.categories.push(category);
        this.msgs = [{ severity: 'error', summary: 'Could not delete category', detail: error.status + '-' + error.error }]; <-- getting object without error attribute and no info from the server
      }
    );
  },
  reject: () => this.categories.push(category)
});

}

My question is how to i keep the original error object instead of what im actually getting if i don't implements this HttpInterceptor than my controllers gets the normal error object

Answer 1

我必须将另一个导入添加到我的HttpInterceptor实现中

import 'rxjs/add/observable/throw';