Error Handling

• We use the catchError operator to catch the error
• We can create a general error handling method that can process the error internally while surfacing a user friendly error via throwError

private handleError(error: HttpErrorResponse) {
  if (error.error instanceof ErrorEvent) {
    // A client-side or network error occurred. Handle it accordingly.
    console.error('An error occurred:', error.error.message);
  } else {
    // The backend returned an unsuccessful response code.
    // The response body may contain clues as to what went wrong,
    console.error('Error Status: ', error.status);
    console.error('Error Details: ', error.error);
  }
  // return an observable with a user-facing error message
  return throwError('Something bad happened; please try again later.');
};