Slim framework: Display an error page using Twig - error-handling

Question

I would like to display a custom view (using twig view) on production when there's something going wrong with my slim3 application.
I read the documentation concerning error handling but I cannot get the handler to display a twig view.
So this is working (displaying the error message in my browser):
if ('development' !== $container->get('settings')['environment']) {
$container['errorHandler'] = function($c) {
return function ($request, $response, $exception) use ($c) {
$c->get('logger')->critical("An error occured", [$exception->getMessage()]);
return $response->write('An error occurred (message: "' . $exception->getMessage(). '").');
};
};
}
but this is not working, ie. it's not displaying the view using the template (instead I get a blank page in my browser):
if ('development' !== $container->get('settings')['environment']) {
$container['errorHandler'] = function($c) {
return function ($request, $response, $exception) use ($c) {
$exceptionMessage = $exception->getMessage();
$settings = $c->get('settings');
$view = $c->get('view');
$data = [
'app' => $settings['app'],
'title' => 'Error',
'exceptionMessage' => $exceptionMessage
];
$c->get('logger')->critical("An error occured", [$exception->getMessage()]);
return $view->render($response, '500.twig', $data);
};
};
}
I really don't get why it's not working. Any ideas?

Answer 1

The error handler cannot catch all errors. PHP Fatal errors and syntax errors it will not catch because of the way PHP deals with Fatal/Parsing errors. Unfortunately there is no way to deal with those types of errors in PHP. An example could be a syntax error or out of memory error. Neither is recoverable

Answer 2

Just to add an observation,
to make twig render anything usually you echo $view->render ...