This post originated from an RSS feed registered with Ruby Buzz by rwdaigle. Original Post: What's New in Edge Rails: Easy Memoization Feed Title: Ryan's Scraps Feed URL: http://feeds.feedburner.com/RyansScraps Feed Description: Ryan Daigle's various technically inclined rants along w/ the "What's new in Edge Rails" series. Latest Ruby Buzz Posts Latest Ruby Buzz Posts by rwdaigle Latest Posts From Ryan's Scraps

Most people will recognize the pattern of memoization to provide a basic caching mechanism (that’s not a misspelling, it really doesn’t have an ‘r’) :

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class Person < ActiveRecord::Base
  def social_security
    @social_security ||= decrypt_social_security
  end
  ...
end

The big problem with this common type of memoization is that you’ve littered your method implementation with caching logic. Caching is best applied in a transparent manner – and ActiveSupport now lets you easily insert memoization into your classes:

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class Person < ActiveRecord::Base

  # Memoize the result of the social_security method after
  # its first evaluation
  memorize :social_security

  def social_security
    decrypt_social_security_for
  end
  ...
end

memorize transparently aliases the method and stores the value of your method’s first evaluation in an instance variable – giving you the same functionality of the unrefined var ||= ... implementation with much less clutter. So start giving memorize some play – it’s just the right thing to do.

tags: ruby, rubyonrails