Rails Cacheable Module

cacheable.rb

module Cacheable
  extend ActiveSupport::Concern

  def cacheback(relationship)
    if relationship.cacheable_attributes.any?
      relationship.target_attributes.each do |target_attribute|
        relationship.target.each { |member| member.send("calc_#{target_attribute}")}
      end
      relationship.target.each(&:save!)
    end
  end

  class CacheRelationship
    attr_accessor :target, :source, :attributes

    def initialize(source, target, attributes, options={})
      self.source = source
      self.target = target
      self.attributes = attributes
    end

    def cacheable_attributes
      @cacheable_attributes ||= calc_cacheable_attributes
    end

    def target_attributes
      @target_attributes ||= calc_target_attributes
    end

    def calc_target_attributes
      attributes.is_a?(Hash) ? cacheable_attributes.keys : cacheable_attributes
    end
    private :calc_target_attributes

    def calc_cacheable_attributes
      if attributes.is_a? Hash
        attributes.select { |target_attribute, source_attribute| source.changed.include?(source_attribute.to_s) || source.destroyed? }
      else
        attributes
      end
    end
    private :calc_cacheable_attributes

    def target=(value)
      @target = *source.send(value)
      @target = @target.compact.each(&:reload)
    end

  end


end