gistfile1.rb

module ActiveModel
  module Typecasting
    extend ActiveSupport::Concern

    #
    # class PoopFactory
    #   include ActiveModel::Model
    #   include ActiveModel::Typecasting
    #
    #   typecast_accessor :color, type: :string
    #   typecast_accessor :price, type: :integer
    # end
    #
    module ClassMethods
      TRUE_VALS = [true, 'true', '1']

      TYPECASTERS = {
        boolean: -> value { TRUE_VALS.include?(value) },
        float:   -> value { value.to_f },
        integer: -> value { value.to_i },
        string:  -> value { value.to_s },
        time:    -> value { Time.parse(value) }
      }

      def typecast_accessors(attributes)
        attributes.each do |key, options|
          typecasted_attribute key, options
        end
      end

      def typecast_accessor(name, options = {})
        define_method name do
          instance_variable_get("@#{name}")
        end

        define_method "#{name}=" do |value|
          instance_variable_set("@#{name}", value)
        end
      end
    end
  end
end