From: Sean O'Halpin <sean.ohalpin@...>
Date: 2007-11-03T09:14:46+09:00
Subject: Re: Who required that!?

On 11/2/07, Sean O'Halpin <sean.ohalpin@gmail.com> wrote:
> On 11/2/07, Joel VanderWerf <vjoel@path.berkeley.edu> wrote:
> > Sean O'Halpin wrote:
> >
> > > Using alias is just a little too fragile. You could always generate a
> > > unique alias name (using GUID or something) which would avoid the
> > > problem, but grabbing a reference to the existing method and using
> > > that is sure to work.
> >
> > Can you do the latter without breaking gem's require?
> >
> > --
> >        vjoel : Joel VanderWerf : path berkeley edu : 510 665 3407
> >
> >
> Yes, that's the point. If you redefine require by chaining to the
> previous definition (rather than aliasing) no other part of the system
> will know the difference. But the proof is in the pudding :)
>
>
> require 'rubygems'
>
> BEGIN {
>   module Kernel
>     h = Hash.new
>     define_method(:requiree) do |of|
>       h[of]
>     end
>
>     r = method :require
>     define_method(:require) do |*a|
>       r.call *a
>       h[a.first] = caller
>     end
>   end
> }
>
> require 'main'
>
> p Kernel.requiree("main")
>
> Main {
>   def run
>     puts "Made it!"
>   end
> }
>
> __END__
> $ ruby requiree.rb
> ["/usr/local/lib/ruby/site_ruby/1.8/rubygems/custom_require.rb:32:in
> `gem_original_require'",
> "/usr/local/lib/ruby/site_ruby/1.8/rubygems/custom_require.rb:32:in
> `require'", "requiree.rb:19"]
> Made it!
>
> Regards,
> Sean
>
>
Scrub that - Joel you're right - it depends on load order. If you use
ruby -rubygems ... this won't work because requiree is grabbing a
reference to the original require method and so bypassing the rubygems
redefinition. It works ok if rubygems aliases requiree's require but
not the other way round. Hmmm...

Regards,
Sean