From: Sebastian <shfriedrich@...>
Date: 2006-12-12T09:50:10+09:00
Subject: Re: Inserting surrounding scope into singelton method definition

Wonderful! For some reason the 2-argument notation in your example 
didn't work for me, but with a Proc as the method definition body all 
is dandy. I had tried class_eval before but ignorantly used it on the 
array instance instead, which of course doesnt work. So, thanks very 
much for your help.

Here's the final code:

returning find(:all, :order => "#{sort_by_term} #{sort_order_term}") do 
|results|
	(class << results; self; end).class_eval do
		define_method(:sorted_by?) { sort_by_term }
		define_method(:sort_order?) { sort_order_term }
        	end
end


On 2006-12-11 18:02:34 -0600, dblack@wobblini.net said:

> 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