Role-based conditionals

Rails
1

in the Rails Recipes book there is a chapter on role-based
authentication. it basically set up priviliges based on what page the
user was able to access. i went through the chapter and felt like i got
a pretty good understanding of how to do it.

now i am needing something a little more advanced though. instead of a
per page (or action) i would like to have certain sections on a page
either show or be hidden based on the role of the user. the best example
i can think of would be on the typo blog. there is an edit button on
each post that only shows up if the user is logged in.

for the most part, i think something like this would be pretty easy, but
i’m mainly posting this because i would like to keep my code clean and
not put a bunch of useless conditionals and actions in my view.

2

Ezra’s acl_system access control plugin creates a helper method. This is
a direct cut-and-paste from that code:

restrict_to “admin | moderator” do

link_to “foo”

end

def restrict_to(logicstring, context = {})
  return false if current_user.nil?
  result = ''
  if permit?(logicstring, context)
    result = yield if block_given?
  end
  result
end