From: dblack@...
Date: 2006-12-12T09:02:34+09:00
Subject: Re: Inserting surrounding scope into singelton method definition

Hi --

On Tue, 12 Dec 2006, Sebastia wrote:

> I have a sorted array (in this case, an ActiveRecord result set) that i want 
> to give awareness of its sorting state. I defined a singelton method on the 
> array but i can't figure out how to insert a value from the surrounding 
> scope. Below is the best i could come up with, but it seems quite horrid (and 
> using plain eval would be even worse i suppose). I seem to remember that 
> there was a better way... Anybody?
>
> Thanks,
> Sebastian
>
> sort_term = "label"
> results = User.find(:all, :order => sort_term)
>
> class << results
> def sorted_by?
> @sorted_by_term
> end
> end
>
> results.instance_variable_set("@sorted_by_term",sort_term)

To get through the barrier of the class and def scopes, you can use
class_eval and define_method:

   (class << results; self; end).class_eval do
     define_method(:sorted_by?, sort_term)
   end

or something along those lines.


David

-- 
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