Use

Timestamper allows you to automatically set http response’s header Last-Modified with value from ActiveResource or ActiveRecord. Currently only supports ActiveResource.

Configuration

Timestamper.config do
  updated_at_column :updated_at  # global default column
end

class Article
  timestamper_column :last_modified  # custom timestamp column
end

To configure rack middleware in a Rails app, add following line to config/environment.rb.

ActionController::Dispatcher.middleware.use Timestamper::RackMiddleware