require 'rubygems'
require 'dm-core'
require 'dm-validations'

class Element
  include DataMapper::Resource

  property :id, Serial
  property :type, Discriminator
end

class Textbox < Element
  property :content, Text
  validates_present :content

  def use_content
    self.content
  end
end

DataMapper.setup(:default, "sqlite3:///#{Dir.pwd}/content.db")
DataMapper.auto_upgrade!

box = Textbox.create({:content => 'hello'})
Element.all.each {|e| puts e.use_content}