gistfile1.txt

  class SelectedDoorkeeperFor < DoorkeeperFor
    def initialize(*args)
      options = args.pop if args.last.is_a? Hash
      super(options)
      only(args)
    end

    private

    def only(actions)
      @filter_options[:only] = actions
    end
  end

  class DoorkeeperForBuilder
    def self.create_doorkeeper_for(foo, bar, *args)
      case foo
      when :all
        AllDoorkeeperFor.new(bar || {})
      when Hash, nil
        fail InvalidSyntax
      else
        SelectedDoorkeeperFor.new(foo, bar, *args)
      end
    end
  end