How to get the current_user in a model observer?

Question

Given the following models:

Room (id, title)
RoomMembers (id, room_id)
RoomFeed, also an observer

When a Room title is updated, I want to c

Answer 1

Create the following

class ApplicationController
  before_filter :set_current_user

  private
  def set_current_user
    User.current_user = #however you get the current user in your controllers
  end
end

class User
   ...
   def self.current_user
     @@current_user
   end
   def self.current_user= c
     @@current_user = c
   end
   ...
end

Then use...

User.current_user wherever you need to know who is logged in.  

Remember that the value isn't guaranteed to be set when your class is called from non-web requests, like rake tasks, so you should check for .nil?