From: Brian Candler <B.Candler@...>
Date: 2003-04-05T23:35:02+09:00
Subject: Re: Plugins (sort off)

On Sat, Apr 05, 2003 at 11:09:50PM +0900, Damphyr wrote:
> Class Experiment
>    def doMethod(nameofmethod)
> 	self.extend nameofmethod
>    end
> end
> 
> the above does not execute (I know, I tried :)) ) and it would be silly 
> if it did (I guess I'm a bit silly for trying :) ).
> And that is what that
> 
>  very_clever_method_takes_string_returns_module(modulename)
> 
> should do.

Ah - I thought you were going to return the module itself, not a string of
the module name. See Guy's response about const_get.

There is always the string version of eval:

   eval "extend #{nameofmodule}"

but I feel that to be rather kludgy, if not downright dangerous.

Something else which might be useful in your toolbox is Kernel#autoload:

  # file1.rb
  module Foo
    def bar 
      puts "hello"
    end
  end

  # main.rb
  autoload :Foo, "file1.rb"
  a="abc"
  b="def"
  a.extend Foo
  b.extend Foo
  a.bar   #>> "hello"
  b.bar   #>> "hello"

This has the advantage of only pulling in the source files when required, as
long as you know in advance what the module names are.

Regards,

Brian.