testing out instance define methods for models

foo.rb

class Foo

  def self.set_foo
	@foo = 1
  end

  def self.print_foo
	puts "class isntance foo = #{@foo}"
  end

  def self.increment_foo
	@foo = @foo + 1
  end

  def self.get_foo
	@foo
  end

  def self.multiply_instance multiplier
    class_eval do
      define_method(:multiply_foo) do
        @multiplier ||= multiplier
        puts "multiplying foo by #{@multiplier}"
        puts "(arg was #{multiplier})"
        puts self.get_foo
        puts @multiplier

        @foo = self.get_foo * @multiplier
      end
    end
    self
  end


  def initialize
  	self.get_foo
  	puts "initialized Foo"
  end

  def print_foo
  	puts "instance foo = #{@foo}"
  end

  def get_foo
  	if !@foo #@foo doesnt exist in class instance 
      @foo = Foo.get_foo
  	end
  	@foo
  end

  def get_class_foo
    puts self.class.get_foo
  end


end

Foo.set_foo
Foo.print_foo

foo = Foo.multiply_instance(3).new
foo.print_foo
foo.multiply_foo
foo.print_foo
foo.multiply_foo
foo.multiply_foo
foo.multiply_foo
foo.multiply_foo
foo.multiply_foo
foo.print_foo