Rails - Oct 2008 - Pass option value to InstanceMethods define_method

Hello,

I''m trying to develop a ActiveRecord plugin but run into the following
problem: I pass arguments to

 write_inheritable_attribute :some_field, ''value''
 class_inheritable_reader    :some_field

in ClassMethods module and I''m available to get them in InstanceMethods
with self.class.some_field. But when I try to do like this:

define_method "#{self.class.some_field}"
...

or

class_eval <<-eval
  def #{self.class.some_field}
   ...
  end
eval

I get NoMethodError: undefined method `some_field'' for Module:Class

Anybody could help with this?
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On Oct 7, 7:19 pm, Vidmantas Kabošis <rails-mailing-l...@andreas-
s.net> wrote:
> Hello,
>
> I''m trying to develop a ActiveRecord plugin but run into the
following
> problem: I pass arguments to
>
>  write_inheritable_attribute :some_field, ''value''
>  class_inheritable_reader    :some_field
>
> in ClassMethods module and I''m available to get them in
InstanceMethods
> with self.class.some_field. But when I try to do like this:
>
I may not be reading you correctly, but at that point do you not need
to be using self.some_field ? (self.class.some_field would be trying
to find that method on Class or something like that.

Fred
> define_method "#{self.class.some_field}"
> ...
>
> or
>
> class_eval <<-eval
>   def #{self.class.some_field}
>    ...
>   end
> eval
>
> I get NoMethodError: undefined method `some_field'' for
Module:Class
>
> Anybody could help with this?
> --
> Posted viahttp://www.ruby-forum.com/.
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Frederick Cheung wrote:
>  using self.some_field ? 
I''ve tried this too, but then I get NoMethodError: undefined method 
`some_field'' for MyModule::InstanceMethods:Module
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On Oct 8, 8:36 am, Vidmantas Kabošis <rails-mailing-l...@andreas-
s.net> wrote:
> Frederick Cheung wrote:
> >  using self.some_field ?
>
> I''ve tried this too, but then I get NoMethodError: undefined
method
> `some_field'' for MyModule::InstanceMethods:Module
I think you need to post more of your code. It''s not clear where you
are calling what which is rather important here.

Fred
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Frederick Cheung wrote:
> I think you need to post more of your code. 
Sure:

module MyModule
  def self.included(base)
    base.extend ClassMethods
  end

  module ClassMethods
    def money_is(field_name)
      write_inheritable_attribute :some_field, ''value''
      class_inheritable_reader    :some_field

      self.send(:include, MyModule::InstanceMethods)
    end
  end

  module InstanceMethods
    define_method "#{self.some_field}" do
      # code
    end
  end
end
> script/console 
Loading development environment (Rails 2.1.0)
/home/vidmantas/projects/my_project/vendor/plugins/my_module/lib/my_module.rb:16:NoMethodError:
undefined method `some_field'' for MyModule::InstanceMethods:Module

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On 8 Oct 2008, at 11:11, Vidmantas Kabošis wrote:
>
> Frederick Cheung wrote:
>> I think you need to post more of your code.
>
> Sure:
>
> module MyModule
>  def self.included(base)
>    base.extend ClassMethods
>  end
>
>  module ClassMethods
>    def money_is(field_name)
>      write_inheritable_attribute :some_field, ''value''
>      class_inheritable_reader    :some_field
>
>      self.send(:include, MyModule::InstanceMethods)
>    end
>  end
>
>  module InstanceMethods
>    define_method "#{self.some_field}" do
>      # code
>    end
>  end
> end

OK. when the define_method runs, self is the module InstanceMethods.  
At that point it hasn''t even been included in anything so there is no  
way to get the value of some_field.

I would just be doing this from the money_is method (or if you want to  
keep the InstanceMethods module then from its included hook.

Fred


>
>
>> script/console
> Loading development environment (Rails 2.1.0)
> /home/vidmantas/projects/my_project/vendor/plugins/my_module/lib/ 
> my_module.rb:16:NoMethodError:
> undefined method `some_field'' for MyModule::InstanceMethods:Module
>
> -- 
> Posted via http://www.ruby-forum.com/.
>
> >

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Got it, thank you!

Frederick Cheung wrote:
> I would just be doing this from the money_is method (or if you want to
> keep the InstanceMethods module then from its included hook.
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