module Rescue
Ruby on Rails 2.2.3
Since v2.2.3Actions that fail to perform as expected throw exceptions. These exceptions can either be rescued for the public view (with a nice user-friendly explanation) or for the developers view (with tons of debugging information). The developers view is already implemented by the Action Controller, but the public view should be tailored to your specific application.
The default behavior for public exceptions is to render a static html file with the name of the error code thrown. If no such file exists, an empty response is sent with the correct status code.
You can override what constitutes a local request by overriding the local_request? method in your own controller. Custom rescue behavior is achieved by overriding the rescue_action_in_public and rescue_action_locally methods.