Design Patterns in Ruby

I gave talk on Design Patterns in Ruby at 'Pune Ruby Users Group' meeting on 6th July, 2013. Here are the code snippets https://gist.github.com/anildigital/5939892

Transcript

1. Design Patterns in Ruby Anil Wadghule Ruby hacker Sunday, 7 July 13
2. What are Design Patterns? Sunday, 7 July 13
3. What are Design Patterns? Design Patterns are nothing but decent pre-loaded solutions to common problems Sunday, 7 July 13
4. What are Design Patterns? They are worth knowing because they are solutions to common problems Sunday, 7 July 13
5. Are ‘Design Patterns’ restricted to certain programming languages? NO! They are programming language independent. They can be implemented in any programming language Most OOP-specific design patterns may be irrelevant to functional languages Sunday, 7 July 13
6. Design Patterns book by Gang of Four It made Design Patterns popular Sunday, 7 July 13
7. Design Patterns categories Creational patterns (Singleton, Builder etc) Structural patterns (Adapter, Composite, Proxy etc) Behavioral patterns (Command, Strategy, Observer etc) Architectural patterns (MVC - Model View Controller etc) Concurrency patterns (Reactor, Thread pool etc) Sunday, 7 July 13
8. Design Patterns we will see are Template Method Strategy Proxy Composite Adapter Decorator Sunday, 7 July 13
9. Template Method Document def render render_title(@title) render_footer(@author) ... end HTML Document Text Document def render_title(t) end def render_author(a) end def render_title(t) end def render_author(a) end Template Method Sunday, 7 July 13
10. Strategy Document def initialize(renderer) @renderer = renderer end def render @renderer.render(self) end HTMLRenderer TextRenderer def render(doc) puts doc.title puts “By #{doc.author}” end def render(doc) ... end Sunday, 7 July 13
11. Strategy Separate out the change Composition NOT inheritance Sunday, 7 July 13
12. Proxy Document def render(doc) puts doc.title puts “By #{doc.author}” end ProxyDoc def render if allowed? @doc.render end end client Sunday, 7 July 13
13. Adapter Document def render end Adapter def print @doc.render end client Sunday, 7 July 13
14. Composite Document def render end Composite def render @subdocs.each do |s| s.render end end client Document def render end Document def render end Sunday, 7 July 13
15. Decorator Document def render end Decorator def to_japanese translate(@doc.paragraphs) end def render @doc.render + “do awesome” end client Sunday, 7 July 13
16. Recommended Book Sunday, 7 July 13
17. References http://en.wikipedia.org/wiki/Software_design_pattern Sunday, 7 July 13
18. Thanks! Sunday, 7 July 13
19. Questions? Sunday, 7 July 13
20. @anildigital on twitter anildigital@gmail.com Sunday, 7 July 13