From: aurelianito <aurelianocalvo@...>
Date: 2005-10-11T05:46:53+09:00
Subject: Re: Method added hook

> > I want more granularity than what the five (0-4) $SAFE levels offer. I
> > want to be able to say  "can write in file A but not in file B"

(...)

> Regarding the method hooks, one thing that you can do to complicate things
> somewhat is to do something like this (not tested):
>
> class SomeClass
>    def some_method(*a, &b)
>      # ...
>    end
>
>    alias_method :__safety__, :some_method
>
>    def self.method_added(sym)
>      unless @my_add
>        # Revert back to original
>        if sym == :some_method
>          alias_method :some_method, :__safety__
>        end
>      else
>        @my_add = false
>      end
>    end
> end

I've patched it a little bit and it worked nicely.

class Klass
   def foo
      puts "foo"
   end

   alias_method :__safety__, :foo

   def self.method_added(sym)
     if sym == :foo && ! caller.find { |call| /method_added/ =~ call }
         alias_method :foo, :__safety__
     end
   end
end

class Klass
   def foo
      puts "evil"
   end
end

a = Klass.new
a.foo // prints "foo"

Do you know if this solution is thread safe or not?,
Aureliano.