Passing arguments to an around_filter

gistfile1.rb

# app/controller/articles_controller.rb
around_filter { |controller, action|  controller.send(:add_published_scope, Article){ action.call } }

# app/controller/application_controller.rb
def add_published_scope(klass = nil, &block)
  unless klass
    klass = controller_name.classify.constantize
  end
  klass.with_scope(:find => klass.where("published_at <= ?", Time.zone.now)) do
    yield
  end
end