Hooks pattern

hooks_pattern.rb

module HooksForThisUse
  
  def before_handle_print_it(*args)
    p "About to run #{self} with #{args.inspect}"
  end
  
  def after_handle_print_it_again(*args)
    p "Already ran #{self} with #{args.inspect}"
  end
  
  def on_failure_print_it_one_more_time(*args)
    p "That utterly failed #{self} with #{args.inspect}"
  end
end

module Hookifier
  
  
  def self.included(klass)
    klass.extend ::Hookifier::ClassMethods
  end
  
  module ClassMethods

      #
      # Takes a splat of method names, and wraps them with "wrap_hooks_around_it".
      #
      def hooked_methods(*methods)
        methods.each do |meth|
          m = instance_method meth
          define_method meth do |*args|
            wrap_hooks_around_it m.bind(self), *args
          end
        end
      end
  end
  
  
  def wrap_hooks_around_it(method, *args)
    before_hooks  = self.methods.grep(/^before_handle/).sort
    after_hooks   = self.methods.grep(/^after_handle/).sort
    failure_hooks = self.methods.grep(/^on_failure/).sort
    
    begin
      begin
       before_hooks.each do |hook|
         self.send(hook, *args)
       end
      rescue Exception => e
       #Exit gracefully? p "#{e}"
       return false
      end
      
      #do stuff here
      method[*args]

      #if exception are raise while "doing", these hooks will never run.
      begin
        after_hooks.each do |hook|
           self.send(hook, *args)
         end
       rescue Exception => e
        #Exit gracefully? p "#{e}"
        return false
       end


     # If an exception occurs during the execution, look for an
     # on_failure hook then re-raise.
     rescue Object => e
       failure_hooks.each { |hook| self.send(hook, e, *args) }
       raise e
     end
    
  end
end


class TestThing
  include Hookifier
  include HooksForThisUse
  
  def initialize(full_url, username = nil, password = nil)
    @full_url = full_url
    @username = username
    @password = password
  end
  
  def call_remote_service(*args)
    p "remote service called with args: #{args.inspect}"
  end
  
  def call_remote(*args)
    raise "crap"
  end
  
  hooked_methods :call_remote_service, :call_remote
  
end

t = TestThing.new("somewhere")
t.call_remote_service("daniel", :args)
t.call_remote(:more_args)