before/after

object_with_before_after_around.rb

class Object
  class << self
    # @example
    #   before(:initialize) do
    #     log.debug "Initializing chicken"
    #   end
    def before(method_name, &block)
      raise "Requires block" unless block_given?

      original = instance_method(method_name)
      define_method(method_name) do |*args, &runtime_block|
        block.call *args, &runtime_block
        original.bind(self).call *args, &runtime_block
      end
    end

    # @example
    #   after(:initialize) do
    #     log.debug "Initialized chicken"
    #   end
    def after(method_name, &block)
      raise "Requires block" unless block_given?

      original = instance_method(method_name)
      define_method(method_name) do |*args, &runtime_block|
        original.bind(self).call *args, &runtime_block
        block.call *args, &runtime_block
      end
    end

    # @example
    #   around(:play) do |volume = 1, speed = 1, looping = false, &block|
    #     block.call(volume * @@global_volume, speed, looping)
    #   end
    def around(method_name, &block)
      raise "Requires block" unless block_given?

      original = instance_method(method_name)
      define_method(method_name) do |*args, &runtime_block|
        block.call(*args) do |*yielded_args|
          original.bind(self).call *yielded_args, &runtime_block
        end
      end
    end
  end
end