Poor Mans Hook

hook.rb

module PoorManHook

  module ClassMethods

    private

    def after(*syms, &block)
      syms.each do |sym| # For each symbol
        str_id = "__#{sym}__after__"
        unless private_instance_methods.include?(str_id)
          alias_method str_id, sym        
          private str_id                  
          define_method sym do |*args|    
            ret = __send__ str_id, *args  
            block.call(self,              
              :method => sym,
              :args => args,
              :return => ret
            )
            ret
          end
        end
      end
    end

    def before(*syms, &block)
      syms.each do |sym|
        str_id = "__#{sym}__before__"
        unless private_instance_methods.include?(str_id)
          alias_method str_id, sym
          private str_id
          define_method sym do |*args|
            block.call(self,
              :method => sym,
              :args => args,
              :return => self
            )
            __send__(str_id, *args)
          end
        end
      end
    end

  end

  def PoorManHook.included(base)
    base.extend(ClassMethods)
  end

end

usage.rb

class Foo
  include PoorManHook

  def bar(one, two)
    puts one + two
  end

  after :bar do |rec, args|
    puts "after"
  end

  before :bar do |rec, args|
   puts "before"
  end

end

Foo.new.bar("1", " 2")