gopher-proxy/docs/errors-notfound-handler.markdown

Not Found Handler [not-found-handler]

It is an inevitability that someone will request a page that does not exist. The Slim application lets you easily define a custom Not Found handler with the Slim application's notFound() instance method. The Not Found handler will be invoked when a matching route is not found for the current HTTP request. This method may be invoked in two different contexts.

When defining the handler

If you invoke the Slim application's notFound() instance method and specify a callable object as its first and only argument, this method will register the callable object as the Not Found handler. However, the registered handler will not be invoked.

$app = new Slim();

//For PHP >= 5.3
$app->notFound(function () use ($app) {
    $app->render('404.html');
});

//For PHP < 5.3
$app->notFound('custom_not_found_callback');
function custom_not_found_callback() {
    $app = Slim::getInstance();
    $app->render('404.html');
}

When invoking the Not Found handler

If you invoke the Slim application's notFound() instance method without any arguments, this method will invoke the previously registered Not Found handler.

$app = new Slim();

$app->get('/hello/:name', function ($name) use ($app) {
    if ( $name === 'Waldo' ) {
        $app->notFound();
    } else {
        echo "Hello, $name";
    }
});