From: hipster <hipster@...4all.nl>
Date: 2001-07-23T21:24:13+09:00
Subject: [ruby-talk:18340] Re: Ruby, Python and Objects philosophy

On Mon, 23 Jul 2001  21:03:34 +0900, Lloyd Zusman wrote:
> 
> And now, I have a question:  could you show us how the example above would
> be coded in Ruby?  Your pseudo-code is very nice, but a good, concrete,
> totally runnable Ruby example of the exact logging scenario that you have
> spoken about would be even better.

Logging example using Aspect Oriented Programming (get aspectr from
the RAA):

require "aspectr"
include AspectR

class Logger < Aspect
  def wrap(target, *methods)
    super(target, :enter, :exit, *methods)
  end

  def enter(method, object, *args)
    puts "enter #{object.class}::#{method}"
  end

  def exit(method, object, *args)
    puts "exit #{object.class}::#{method}"
  end
end


class SomeTargetClass
  def method_a
    puts "method_a"
  end
end


logger = Logger.new

# wrap one method on the class. One can also wrap a list of methods, both
# on classes and instances.
logger.wrap(SomeTargetClass, :method_a)

SomeTargetClass.new.method_a

# ->
# enter SomeTargetClass::method_a
# method_a
# exit SomeTargetClass::method_a


Analogue solutions for timers, synchronisation, design patterns, & c.
Warning: AOP is contagious  :)

        HTH,
        Michel