Object Mapper for kvs

okm.rb

module PConfig
  def self.setup params
    @store = params[:store]
  end
  def self.store
    @store
  end
end

class Index
  def initialize model
    @store = PConfig.store
    @model = model
  end

  def add property, index
    key = @model.to_s + "Index" + property 
    if @store.key? key
      @store[key] << index
    else
      @store[key] = [index]
    end
  end

  def get property
    key = @model.to_s + "Index" + property 
    @store[key].map{|index| (@model.to_s + property + index.to_s)}
  end
end

module Persistable
  def Object.properties *names
    names.map{|x| x.to_s }.each do |name|
      define_method(name){ @self[name] }
      define_method(name+"="){ |value| @self[name] = value }
    end
  end

  def Object.foreigns relesions
    relesions.each do |relesion|
      name = relesion[0].to_s
      pk = relesion[1].to_s
      define_method name do 
        model = eval(name.sub(/^(.?)/){ $1.upcase })
        model.new @store, @self[pk]
      end
    end
  end

  define_method("initialize") do |pk|
    key = self.class.to_s + pk.to_s
    @store = PConfig.store
    @self = if @store.key? key
      @store[key]
    else
      @store[key] = {}
    end
  end

end

class Item
  include Persistable
  properties "isbn", :title, :price
end

class Order
  include Persistable
  properties :isbn 
  foreigns :item => :isbn
end

# example
PConfig.setup :store => {}

item = Item.new "123456789"
item.isbn = "123456789"
item.title = "Hello World"

index = "1"

order = Order.new "koduki" + index
order.isbn = "123456789"

Index.new(Order).add("koduki", index)
orders = Index.new(Order).get("koduki")

puts orders.first.item.title