Altair::Controller::RescueFrom

Altair — controller-level exception handling.

Altair::Controller::RescueFrom backs the rescue_from controller DSL. A controller names an exception class and a handler method; when an action (or one of its callbacks) raises a matching exception, the router's dispatch wrapper invokes the handler instead of letting the error bubble to the application's error pages. Handlers inherit across the controller hierarchy, and subclass exceptions match the registered type.

Matching is captured as a compiled proc per registration (e.is_a?(Foo)), not a runtime class lookup — Crystal exposes no reflection for dynamic is_a? calls, so the type check happens at compile time.