This document discusses key differences between Ruby objects and objects in other languages. It covers 7 main points: 1) Ruby allows syntax omission; 2) Ruby uses accessor methods instead of properties; 3) operators are methods; 4) Ruby supports open classes; 5) Ruby enables meta-programming through techniques like class_eval; 6) Ruby uses modules for multiple inheritance and mixins; 7) Ruby does not enforce private and protected methods in the same way as other languages. The document provides pros and cons for each point and emphasizes how Ruby's flexibility allows for abstraction, reduced duplication, and extensibility of objects.

1. Ruby Object Design

2. Eddie Li (ADZ)
eddie@visionbundles.com
http://adz.visionbundles.com
Github: afunction
Facebook: /adz.624

3. A difference between Ruby
object and other languages

4. 1. syntax omission

10. Pros
1. Make your codes more readable to a human.
(model validation, routes, rspec, view helper)
Cons
1. High learning curve for beginners.
(Easy to misunderstanding)

11. 2. No REAL property
class/instance variables
and
method instead.

12. attr_accessor / attr_reader / attr_writer

13. Access via class/instance variable

15. 3. Operator is also a method
magic!

17. def +
def -
def *
def /
def <<
def ==
def ===

18. 4. Open Class

20. 5. Meta-programming
Generate code … by code

21. wrapper abstraction behavior

22. Pros
1. Split logics to different level and make your business logic clean.
2. Increase productive.
3. Follow DRY code principle like there is no limitation.

23. Cons
1. Hard to maintain (but it can be solve)
2. Hard to name variables and methods for abstraction behavior.
3. Hard to understand abstraction behavior codes from time to time.

24. class_eval
define_method
define_singleton_method

25. 6. module & class
like PHP Traits
multi inheritance
break top down inheritance

26. a. DRY duplicate method

27. b. callback when some class included
“base” means the class that include this module.

28. It can help you…
1. Modular behavior
2. Modular abstraction behavior with meta-programming
3. Reduce code duplication

29. Pros
1. Easy to organize a huge/fat class
2. Design/extend object flexible

30. Cons
1. Hard to read and write unit-test
(when modules with high dependent context)
2. Hight learning curve
3. Easy to misleading

31. 7. skip “private, protected”
method protection

32. “send” method will skip “private, protected

33. combine send and include method with module
extend class outside without changing exists code.

34. Live Coding.
aka Demo!

35. Q&A
Thank you.