Class Instance Variables

Use Class instance Variables

We all know that class variables such as @@ are dangerous to use due to their leaky inheritance.


<script src="https://gist.github.com/surgentt/9464842.js"></script>class Presentaion < Document


WHAT IS GOING ON HERE

 The class << self syntax opens up a classes singleton class.
  This allows you to specialize the behavior of methods called on that specific object.

http://stackoverflow.com/questions/2505067/class-self-idiom-in-ruby

Object
    ^
     |
  <Singleton Class>
    ^
    |
Instance

Singleton Method is a method that is defined for exactly one object instance.


The <Singleton Class> is only invoked when it is filled with something.

  - An example of this is a method on an instance variable.

hand_built_stub_printer = Object.new def hand_built_stub_printer.avaiable? true end