[Rails] authorize state transitions

Does anybody know how to authorize state transitions? I'm using
state_machine in my rails app to define the state of an Article
(published or unpublished). I'm also using declarative_authorization to
determine the authorizations a user has. But how do I authorize a state
transistion (determine if the user has the right to publish the
Article)?

Kind regards,

H.J. Blok
--
Posted via http://www.ruby-forum.com/.