Handling specific page editing permissions for members

Hi all,

I’m building a custom content management system for a website in Rails.
What’s the best way of restricting members to being able to edit
specific pages?

For example, a members might belong to a branch, along with many other
members (n:1 relationship). But I only want specific members to be able
to edit their branch page on the site, and no other branch pages.

Should I be making a join table with an extra attribute for permission
to edit? I understand that it’s a bit messy in rails 1.0, and 1.1 will
have has_many :members, :through => branch_permissions, or something
like that. Is it worth waiting, or is there a better way?

Thanks!

Tom