This library provides a Not Found handler so that returned 404 responses are in the problem details format.
This handler will create a problem details Response with a 404 status code and
a problem details body that will be rendered in either JSON or XML as required by
the request's Accept header.
This handler will only return a response if the request's accept header indicates that it will accept either JSON or XML.
To use this handler in Expressive add it into your pipeline (usually pipeline.php)
immediate before the default NotFoundHandler:
$app->pipe(\Zend\ProblemDetails\ProblemDetailsNotFoundHandler::class);
$app->pipe(NotFoundHandler::class);