acts_as_tree help

What I'm working with is Events. Some events are multi-day, so to track that, I want to use acts_as_tree.

The problem is this: for pretty much any attribute, I want to return the attribute as normal, except when it's nil.Then I want to return the parent's attribute. I've tried experimenting with alias_method. I can upgrade to rails 1.2 to use alias_attribute if that's what I need to do.

Can anyone point me in the right direction on this?