gistfile1.rb

class Bucket < ActiveRecord::Base
  include Sluggable
  Fu = FileUtils

  belongs_to :collection

  collection_reader = instance_method 'collection'
  define_method('collection') do |*a|
    @collection ? @collection : collection_reader.bind(self).call(*a)
  end

  collection_writer = instance_method 'collection='
  define_method('collection=') do |value|
    @collection = collection_writer.bind(self).call(value)
  end