Include Ruby/Rails module with arguments/options

immutable.rb

# Usage
class Payment < ActiveRecord::Base
  #  Readonly columns
  include Immutable.for :customer_id, :amount
end

# Implementation 1: Rails Concern
module Immutable
  extend ActiveSupport::Concern

  included do
    validate :ensure_immutable
  end

  def self.for(*args)
    mod = Immutable
    mod.send(:define_method, :immutable_options) do
      args
    end

    mod
  end

  private

  def ensure_immutable
    if persisted?
      immutable_options.each do |attr|
        errors[attr.to_sym] << 'immutable' if changed.include?(attr.to_s)
      end
    end
  end
end


# Implementation 2: Ruby Module
module Immutable
  def self.for(*args)
    Module.new do
      define_method :ensure_immutable do
        if persisted?
          args.each do |attr|
            errors[attr.to_sym] << 'immutable' if changed.include?(attr.to_s)
          end
        end
      end

      def self.included(included_by)
        included_by.validate :ensure_immutable
      end
    end
  end
end