A humble contribution to Rails

In the upcoming Rails 2.0 there's a nice feature to be able to extract and DRY exception handling in controllers. If you declare this at the class level

  rescue_from SomeException, :with => :some_action

Rails catches SomeExceptions raised by any action and invokes some_action.

The initial implementation provided a useful feature but there was room for improvement. It used and underlying hash table with exception class names as keys and handlers as values. When an exception was being treated a table lookup by name was done. Thus, exception inheritance was not taken into account. That's important because a normal use case for that feature is to declare catchalls. Additionally, handler inheritance or priority were not expressable.

My coffee and I wrote a patch that adds those features and a few others the core team suggested it would be nice to have, and it is already in trunk.