Handling Missing Controllers
Monorail provides us with the concept of a rescue to handle exceptional circumstances that might occur when processing a request. Rescues can be attached to specific exception types by specifying particular attributes on your controllers. Rather than go into that in this post I’d recommend you take a look here.
You probably noticed the nasty message you get when requesting nonexistent controller:
Luckily, Monorail provides an explicit rescue for these circumstances. All you need to do to enable this is add a 404.vm or 404.brail to the /views/rescues directory depending on your choice of view engine.