Globale HTTP-Fehlerbehandlung mittels funktionaler Interzeptoren

import { HttpInterceptorFn, HttpErrorResponse } from '@angular/common/http';
import { inject } from '@angular/core';
import { catchError, throwError } from 'rxjs';
import { NotificationService } from './notification.service';
 
export const errorHandlingInterceptor: HttpInterceptorFn = (req, next) => {
  const notifier = inject(NotificationService);
 
  return next(req).pipe(
    catchError((error: HttpErrorResponse) => {
      let message = 'An unexpected server error occurred.';
 
      if (error.status === 404) {
        message = 'The requested resource was not found.';
      } else if (error.status === 403) {
        message = 'Access denied. You lack the required permissions.';
      } else if (error.error instanceof ErrorEvent) {
        message = `Client error: ${error.error.message}`;
      }
 
      notifier.showError(message);
      return throwError(() => error);
    })
  );
};