在model/concern中加入enum與對應語言的方法

lang_mapping.rb

# In model:
# include LangMapping
#
# lang_map({
#   status: [[:enabled, 1, "啟動"], [:disabled, 2, "取消"], [:unauthenticated, 0, "註冊中"]],
#   user_type: [[:standard, 0, "標準"], [:vip, 1, "高級"], [:vvip, 2, "最高級"], [:admin, 3, "管理員"]]
# })
# 會產生 class methods: all_xxxxs, instance methods: show_xxxx 2個方法
# 例如 user.show_status 會出現"啟動"、"取消"或"註冊中"


module LangMapping

  extend ActiveSupport::Concern
	module ClassMethods

		def lang_map(settings)
			settings.each do |setting|
				self.define_singleton_method(%Q(enum_#{setting[0].to_s.pluralize})) do
					setting[1].inject({}) {|collection, item| collection.merge!(item[0] => item[1])}
				end
				self.define_singleton_method(%Q(all_#{setting[0].to_s.pluralize})) do
					setting[1].inject([]) do |collection, item|
						collection << [item[2], item[0].to_s]
					end
				end
				define_method(%Q(show_#{setting[0].to_s})) do
					collections = setting[1].inject({}) do |collection, item|
						collection.merge!(item[0].to_s => item[2])
					end
					return collections[self.send(setting[0].to_s)]
				end
        # 產生enum :xxxx enum_xxxxs
        enum(setting[0] => eval(%Q(enum_#{setting[0].to_s.pluralize})) )
			end
		end
	end

	module InstanceMethods

	end

	def self.included(receiver)
		receiver.extend         ClassMethods
		receiver.send :include, InstanceMethods
	end
end