Ruby Object Design

Eddie Li (ADZ)

eddie@visionbundles.com

http://adz.visionbundles.com

Github: afunction

Facebook: /adz.624

A difference between Ruby object and other languages

1. syntax omission

Cons

1. Make your codes more readable to a human. (model validation, routes, rspec, view helper)

Pros

1. High learning curve for beginners. (Easy to misunderstanding)

2. No REAL propertyclass/instance variables

and method instead.

attr_accessor / attr_reader / attr_writer

Access via class/instance variable

3. Operator is also a methodmagic!

def +def -def *def /

def << def ==

def ===

4. Open Class

5. Meta-programming

Generate code … by code

wrapper abstraction behavior

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.

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.

class_evaldefine_method

define_singleton_method

6. module & classlike PHP Traits

multi inheritancebreak top down inheritance

a. DRY duplicate method

b. callback when some class included

“base” means the class that include this module.

It can help you…

1. Modular behavior2. Modular abstraction behavior with meta-programming3. Reduce code duplication

Pros

1. Easy to organize a huge/fat class2. Design/extend object flexible

Cons

1. Hard to read and write unit-test (when modules with high dependent context)

2. Hight learning curve3. Easy to misleading

7. skip “private, protected” method protection

“send” method will skip “private, protected

combine send and include method with module

extend class outside without changing exists code.

Live Coding.aka Demo!

Q&A Thank you.