From: ts <decoux@...>
Date: 2008-04-28T20:03:18+09:00
Subject: Re: undefined local variable

Johan Eriksson wrote:
>   the_class.class_eval <<-EOA

 First, you don't need the evil eval

> 
>    def self.load_from_file(filename)
>      yaml_dict = YAML::load(File.open(filename))
>      object_list = yaml_dict[yaml_dict.keys[0]].map do |from_file|
>        puts "from_file: #{from_file}"
>        new_obj = self.class.new

  self will be `the_class', this mean that you must write

        new_obj = new

>        from_file.map do |obj|
>          puts "obj: #{obj}"
>          obj_as_list = obj.to_a
>          puts "obj_as_list: #{obj_as_list}"
>          if obj_as_list[1].is_a? String
>              obj_as_list[1] = "'#{obj_as_list[1]}'"
>            end
>          str = "new_obj.#{obj_as_list[0]} = #{obj_as_list[1]}"

 Another occurence of the evil eval

>          eval(str)

>        end
>        new_obj
>      end
>      object_list
>    end
>    EOA

 Try something like this

   def the_class.load_from_file(filename)
      yaml_dict = YAML::load(File.open(filename))
      object_list = yaml_dict[yaml_dict.keys[0]].map do |from_file|
         puts "from_file: #{from_file}"
         new_obj = new
         from_file.map do |obj|
            puts "obj: #{obj}"
            obj_as_list = obj.to_a
            puts "obj_as_list: #{obj_as_list}"
            new_obj.send("#{obj_as_list[0]}=", obj_as_list[1])
         end
         new_obj
      end
      object_list
   end


Guy Decoux