tv_show.rb

class TvShow
  def initialize
    yield self if block_given?
  end
  
  def self.add(&block)
    tv_show = TvShow.new(&block)
    @@shows ||= []
    @@shows << tv_show
  end
end

TvShow.add do |show|
  show.name = "How I met your mother"
  show.file_formats = ["avi", "mp4", "ogg"]
  show.only_new_episodes = true
end