From: "ara.t.howard" <ara.t.howard@...>
Date: 2007-10-14T07:26:25+09:00
Subject: Re: Setter scoping issue


On Oct 13, 2007, at 4:04 PM, James Golick wrote:

> So, I had this really cool idea for a syntax.
>
> class Options
>   attr_accessor :something, :something_else
> end
>
> class Post
>   @@options ||= Options.new
>   def self.options(&block)
>     @@options.instance_eval &block if block_given?
>     @@options
>   end
> end
>
> Post.options.something = "something"
> assert_equal "something", Post.options.something
>
> Post.options do
>   something = "something"
>   something_else = "something_else
> end
> assert_equal "something", Post.options.something
> assert_equal "something_else", Post.options.something_else
>
> That's the idea anyway.  A shorthand for scoping setters.  If you want
> to set one option, you call the whole method chain.  If you want to  
> set
> multiple options, you use a block.
>
> Unfortunately, the setters don't seem to work in the block without an
> explicit self.
>
> Post.options do
>   self.something = "something"
>   self.something_else = "something_else
> end
>
> ...which defeats the entire purpose of the shorthand.
>
> Anybody have any ideas?
> -- 
> Posted via http://www.ruby-forum.com/.
>

cfp:~ > ruby a.rb
cfp:~ > ruby a.rb
cfp:~ > cat a.rb
require 'attributes'  ### gem install attributes

class Options
   attributes :something, :something_else
end

class Post
   @@options ||= Options.new

   def self.options &block
     @@options.instance_eval &block if block_given?
     @@options
   end
end

Post.options.something = "something"
abort unless "something" == Post.options.something

Post.options do
   something "something"
   something_else "something_else"
end
abort unless  "something" == Post.options.something
abort unless  "something_else" == Post.options.something_else

p :success



cfp:~ > ruby a.rb
:success



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