hstore meta programming

hstore_getter_setter.rb

module HstoreSetterGetter
  # To use simply add to your models:
  #
  # include HstoreSetterGetter
  # hstore_attributes :test1, :test2, type: :integer #assumes column_name: :data
  # hstore_attributes :test3, :test4, column_name: :properties #assumes type: :string
  # 
  # Written by Michael Elfassy
  # http://napps.ca
  #
  def self.included(base)
    base.extend ClassMethods
  end
  module ClassMethods
    def hstore_accessor(*args)
      options = {}
      options.update(args.extract_options!)
      hstore_attribute = options[:column_name] || "data"
      
      Array(args).flatten.each do |key|
        key = key.to_s

        scope "has_#{key}", lambda { |value| where("#{hstore_attribute} @> (? => ?)", key, value) }
          
        define_method(key) do 
          if data = send(hstore_attribute)
            case options[:type]
            when :integer
              data[key].to_i
            when :boolean
              data[key] == "true"
            else
              data[key]
            end
          end
        end
      
        define_method("#{key}=") do |value|
          send("#{hstore_attribute}=", (send(hstore_attribute) || {}).merge(key.to_s => value))
          send("#{hstore_attribute}_will_change!")
        end
      end
    end
  end  
end