00-0-README

Any of these should be runnable at the command line by `ruby <filename>`.

09-callbacks.rb

# check this out: http://www.nach-vorne.de/2007/3/18/list-of-callback-methods/
module M
  def self.included(base)
    puts "#{base.inspect} just included me!"
  end
  
  def self.extended(base)
    puts "#{base.inspect} just got extended!"
  end
end

class C
  include M
end


class D
  extend M
end

10-pitfall.rb

class C
end

module M
  def hello
    "I am from M"
  end
end

module N
  def hello
    "I am from N"
  end
end

C.send :include, M

puts C.new.hello

class C
  include N
end

puts C.new.hello

11-simple-pitfall-fix.rb

module M
  def hello
    "I am from M"
  end
end

module N
  def hello
    "I am from N"
  end
end

class C
  include M
  alias :original_hello :hello
  include N
end

puts C.new.methods.sort.inspect
puts C.new.respond_to? :original_hello
puts C.new.original_hello
puts C.new.hello

12-another-pitfall.rb

class C
  def hello
    "Hello from C"
  end
end

module M
  def hello
    "Hello from M"
  end
end

puts C.new.hello

C.send :include, M

puts C.new.hello

C.class_eval do
  alias :old_hello :hello
  include M
end

puts C.new.hello

C.class_eval do
  def hello
    "have some h8"
  end
end

puts C.new.hello

99-example-from-lib.rb

# init.rb
ActiveRecord::Base.send :include, ExpectedBehavior::ActsAsArchivalActiveRecordMethods

# acts_as_archival_active_record_methods.rb
module ExpectedBehavior
  module ActsAsArchivalActiveRecordMethods
    def self.included(base)
      base.extend ARClassMethods
      base.send :include, ARInstanceMethods
    end
    
    module ARClassMethods
      def is_archival?
        self.included_modules.map(&:to_s).include?("ExpectedBehavior::ActsAsArchival::InstanceMethods")
      end
    end
   
    module ARInstanceMethods
      def is_archival?
        self.class.is_archival?
      end    
    end
  end
end