validatable module

gistfile1.rb

module Validatable
  extend ActiveSupport::Concern
  
  # Required dependency for ActiveModel::Errors
  extend ActiveModel::Naming

  def validate!
    raise NotImplementedError, 'You need to implement this in the parent class'
  end
  
  def errors
    @errors ||= ActiveModel::Errors.new(self)
  end

  # The following methods are needed to be minimally implemented

  def read_attribute_for_validation(attr)
    send(attr)
  end

  ClassMethods do
    def human_attribute_name(attr, options = {})
      attr
    end
  
    def lookup_ancestors
      [self]
    end
  end
end