Ruby.Metaprogramming. class_eval

Question

There seem to be a mistake in my code. However I just can\'t find it out.

class Class
def attr_accessor_with_history(attr_name)
  attr_name = attr_name.to_s
         


        

Answer 1

Here is what should be done. The attr_writer need be defined withing class_eval instead in Class.

class Class
  def attr_accessor_with_history(attr_name)
    attr_name = attr_name.to_s

    attr_reader attr_name
    #attr_writer attr_name  ## moved into class_eval

    attr_reader attr_name + "_history"

    class_eval %Q{
      def #{attr_name}=(value)
        @#{attr_name}_history=[1,2,3]
      end
    }

end
end