Class: SRSGame::Traitable

Inherits:
Object show all
Defined in:
lib/srs_game.rb

Overview

From Dwemthy’s Array by _why the lucky stiff mislav.uniqpath.com/poignant-guide/dwemthy/

Direct Known Subclasses

Item

Class Method Summary collapse

Class Method Details

.metaclass ⇒ Object

Get a metaclass for this class



139
 
# File 'lib/srs_game.rb', line 139

def self.metaclass; class << self; self; end; end

.traits(*arr) ⇒ Object

Advanced metaprogramming code for nice, clean traits



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# File 'lib/srs_game.rb', line 142

def self.traits( *arr )
  return @traits if arr.empty?

  # 1. Set up accessors for each variable
  attr_accessor *arr

  # 2. Add a new class method to for each trait.
  arr.each do |a|
    metaclass.instance_eval do
      define_method( a ) do |val|
        @traits ||= {}
        @traits[a] = val
      end # define_method
    end # instance_eval
  end # each

  # 3. For each traitable object, the `initialize' method
  #    should use the default number for each trait.
  class_eval do
    define_method( :initialize ) do
      self.class.traits.each do |k,v|
        instance_variable_set("@#{k}", v)
      end
    end
  end

end