1. Class 6 Modules, Inheritance & Building a Gem

2. I am a module! module Awesome #a bunch of method definitions that give #really cool functionality end class Rad include Awesome #more code end Now Rad class can call all the classes and methods defined in Awesome as though they were in Rad

3. Modules... Help with program design and flexibility Encourage modularity

4. No Multiple Inheritance in Ruby Without modules, a class can only inherit from one source, its superclass. You can “mix in” as many Modules as you like. A module can be mixed in to multiple classes.

5. Add the same functionality to multiple classes module Enumerable def each #lots of code end #lots more code end class Array include Enumerable end class Hash include Enumerable end

6. Method Search Path dog= Dog.new dog.talk class BasicObject class Object modules mixed in to Object class class Animal modules mixed in to Animal class class Dog modules mixed in to Dog class

7. Building a Gem write some Ruby code that you want to make available as a gem creating a gem specification file (mygem.gemspec), which is Ruby code running gem build mygem.gemspecto create the gem file (mygem-2.1.gem) More info: http://docs.rubygems.org/read/chapter/5

8. Gem Specification spec = Gem::Specification.new do |s| s.name = 'rfoo' s.version = '1.0' s.summary = 'example gem' s.files = ['myfile.rb', 'README', 'LICENSE.txt'] end By convention, source goes into a /lib directory Then you would put your specs into spec/lib More info: http://rubygems.rubyforge.org/rubygems-update/Gem/Specification.html

9. Building & Installing the Gem gem build test_data.gemspec --> now you have a gem file: test_data-0.0.1.gem gem list test_data --> but you don't have access to the gem yet, you need to install it gem install test_data-0.0.1.gem gem list test_data

10. Using the Gem We Built $ irb >> load 'test_data' LoadError: no such file to load -- test_data from (irb):1:in `load' from (irb):1 >> require 'test_data' => true >> TestData::create_names('foo', 10) => nil

11. Gem Resources Rdoc http://rdoc.sourceforge.net/doc/index.html gem server http://localhost:8808 publish your gems http://gemcutter.org/

12. Time to Party. Thank You!