Unauthorized Request HTTP Interceptor

unauthorized.interceptor.ts

import { Injectable } from '@angular/core';
import { HttpEvent, HttpInterceptor, HttpHandler, HttpRequest, HttpResponse, HttpErrorResponse } from '@angular/common/http';
import { tap } from 'rxjs/operators';

@Injectable({
  providedIn: 'root'
})
export class UnauthorizedHttpInterceptor implements HttpInterceptor {

  intercept(req: HttpRequest<any>, next: HttpHandler) {
    return next.handle(req).pipe(tap(
      (event: HttpEvent<any>) => {
        if (event instanceof HttpResponse) {
          // do stuff with response if you want
        }
      },
      (err: any) => {
        if (err instanceof HttpErrorResponse) {
          if (err.status === 401 || err.status === 403) {
            // TODO: handle unauthorized error response
          }
        }
      }
    ));
  }

}