Invoke 404 Not Found Handler

In slim v4, How can I invoke a 404 Not Found Exception?

More details: if I use:

throw new \Slim\Exception\HttpNotFoundException($request);

It show me Fatal Error, and doesn’t trigger the default 404 slim event.

You will only get a fatal error if you don’t register the Slim ErrorMiddleware:

$app->addErrorMiddleware(true, true, true);

You could also define a custom error handler for the \Slim\Exception\HttpNotFoundException::class.


$errorMiddleware = $app->addErrorMiddleware($displayErrorDetails, $logErrors, $logErrorDetails);

$errorMiddleware->setErrorHandler(\Slim\Exception\HttpNotFoundException::class, function (
    \Psr\Http\Message\ServerRequestInterface $request,
    \Throwable $exception,
    bool $displayErrorDetails,
    bool $logErrors,
    bool $logErrorDetails
) {
    $response = new \Slim\Psr7\Response();
    $response->getBody()->write('My custom 404 error');

    return $response->withStatus(404);

You custom error handler could also be a class with a __invoke() method.

To trigger the 404 error handler just throw a HttpNotFoundException.

throw new \Slim\Exception\HttpNotFoundException($request);

Or you just register a custom default error handler to handle the HttpNotFoundException.

// Add Error Middleware
$errorMiddleware = $app->addErrorMiddleware(true, true, true);

1 Like

Thanks for your reply