From: "ara.t.howard" <ara.t.howard@...>
Date: 2008-04-05T01:58:49+09:00
Subject: Re: Using a string as executable code


On Apr 4, 2008, at 10:37 AM, Peter Marks wrote:
>  realize storing code in a database is kind of a funny idea, but I
> don't see a better alternative for the problem I face. I need to
> generate an array of object customized strings, specially selected  
> from
> a pool of about 500 string functions. The only alternative I see is
> defining about 300 extra frivolous string methods in my model and
> selecting among those based on database values. That doesn't seem any
> less smelly.

there are many easy ways to handle this

i don't know what you mean by 'string function'  but:


cfp:~ > cat a.rb
module StringMethods
   class << self
     def a
       p :a
     end

     def b
       p :b
     end

     def c
       p :c
     end
   end
end

class Module
   def string_methods *list
     list.flatten.each do |m|
       module_eval <<-code
         def #{ m }(*a, &b)
           StringMethods.#{ m }(*a, &b)
         end
       code
     end
   end
end

class Model
   string_methods %w( a b )
end

m = Model.new

m.a
m.b
m.c


cfp:~ > ruby a.rb
:a
:b
a.rb:38: undefined method `c' for #<Model:0x278f8> (NoMethodError)




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