I noticed in my models I had several methods that could use some caching to speed things up a bit, especially because lots of joins were involved to make it happen. I got tired of calling "Rails.cache.fetch __method__, self" over and over and over. Taking a cue from the ActionView::Helpers::CacheHelper 'cache' call and the whole Russian-doll cac…

gistfile1.rb

module CacheHelper
  extend ActiveSupport::Concern
  
  included do
    extend Cacher
    include Cacher
    cattr_accessor :updated_column_name
    self.updated_column_name ||= :change_time
    cattr_accessor :file_location
    cattr_accessor :file_digest
    self.file_location ||= "#{Rails.root}/app/models/#{self.to_s.split('::').join('/').underscore.downcase}.rb" if defined? Rails
    self.file_digest ||= Digest::MD5.hexdigest(File.read(self.file_location)) if self.file_location
  end

  module Cacher
    def cache(key='', options={}, &block)
      unless options[:overwrite_key]
        calling_method = caller[0][/`([^']*)'/, 1]
        key << calling_method << '/'
        key << self.cache_key << '/'
        key << self.file_digest
      end
      puts key if options[:debug]
      filtered_options = options.except(:overwrite_key, :debug)
      Rails.cache.fetch key, filtered_options do
        block.call
      end
    end

  end

  module ClassMethods    
    # Create cache_key for class, use most recently updated record
    unless self.respond_to? :cache_key
      define_method :cache_key do
        key = order("#{self.updated_column_name} DESC").first.cache_key if self.superclass.to_s == "ActiveRecord::Base"
        key << "/#{self.to_s}"
      end
    end
  end

end

gistfile2.rb

class MyClass < ActiveRecord::Base
  include CacheHelper

  def some_cachable_method
    cache do
      # stuff
    end
  end
  
  def some_cachable_method_with_custom_cache_key
    cache ['some special key'] do
      # stuff
    end
  end
  
  def method_with_cach_options
    cache 'my key', expires_in: 30.minutes do
      # stuff
    end
  end

end