Adding setter and getter of attributes of a AR model backed by an Hash

gistfile1.rb

class MyModel < ActiveRecord::Base

  serialize :preferences, Hash

  PREFS_KEYS = [:hostname, :has_retail]

  PREFS_KEYS.each do |key|
    define_method(key) do
      preferences[key]
    end
    define_method("#{key}=") do |value|
      preferences[key]= value
    end
  end
end