gistfile1.rb

module User::Extras
  # ActiveRecord, at the time of this writing, always writes serialized attributes to the database, even if it hasn't changed.
  # See http://github.com/rails/rails/commit/992fda16ed662f028700d63a8dcbd1837f1d58ab for the patch that introduced this.
  # So to get around it, we're going to handle the serialization of the extras hash ourselves.
  
  def self.included(klass)
    klass.class_eval do
      before_save :serialize_extras_attribute
    end
    klass.extend(ClassMethods)
  end
  
  def extras
    @extras ||= begin
      if self.read_attribute(:extras)
        YAML.load(self.read_attribute(:extras))
      else
        {}
      end.with_indifferent_access
    end
  end
  
  def extras=(*args)
    raise "Should never call this, you should only modify keys of the extras hash."
  end
  
  def serialize_extras_attribute
    write_attribute("extras", @extras.to_hash.to_yaml) if @extras
  end
  
  module ClassMethods
    def extras_accessor(*args)
      args.each do |method|
        class_eval <<-METHODS
          def #{method}
            self.extras['#{method}']
          end
          
          def #{method}=(value)
            self.extras['#{method}'] = value
          end
        METHODS
      end
    end
    alias extra_attributes extras_accessor
  end
  
end