Delegating methods to some class

AbstractModel.rb

class AbstractModel
  def self.set_target(model_name)
    @@model_name = model_name
    AbstractModel.class.delegate :find, :to => :"#{@@model_name}"
    AbstractModel.class.delegate :all, :to => :"#{@@model_name}"
  end
end

#AbstractModel.set_target("Product")
#AbstractModel.find(1)


class AbstractModel

  class Product

    delegate :find, :to => :"::Product"
  end

  class Article
    delegate :find, :to => :"::Article"
  end
  def self.build(model_name)
    case model_name
      when "Product"  
        AbstractModel::Product.new
      when "Article"  
        AbstractModel::Article.new  
    end
  end
end

#b = AbstractModel.build("Product")
#b.find(1)

class AbstractModel
  def self.build(model_name)
    eval "class #{model_name.camelize}
      delegate :find, :to => ::#{model_name.camelize}
    end
    #{model_name.camelize}.new"
  end
end

# b = AbstractModel.build("Product")
# c = AbstractModel.build("Article")
# d = AbstractModel::Article.new
# b.find(1)
# c.find(1)
# d.find(1)


class AbstractModel
  def self.build(model_name, methods = [])
    @model_name = model_name
    @methods = methods
    eval "class #{name_for_class}
    #{delegate_body}
    #{name_for_class}.new
    end "
  end

  private
  def self.delegate_body
    @methods.map do |m|
      "delegate :#{m}, :to => :\"#{@model_name.camelize}\""
    end.join("\n")
  end
  def self.name_for_class
    @model_name.gsub('.','_').camelize
  end
end


# d = AbstractModel.build("Article",['all'])
# c = AbstractModel.build("Article.first",['title'])
# puts d.all
# puts c.title

Probably I should change name for something like Interface or MagicBinding