Access of Current Login user in Model

In  your model put the following code what ever the model is let suppose model is User then.

class User < ActiveRecord::Base
  def self.current
    Thread.current[:user]
  end
  def self.current=(user)
    Thread.current[:user] = user
  end
end

After this now in your application controller do like this.

class ApplicationController < ActionController::Base
    def set_current_user
      User.current = current_user
    end
end
class ApplicationController < ActionController::Base
   before_filter :set_current_user
end

Now you can easily fetch the current_user in models by User.current