require 'active_support/concern' require 'active_support/ordered_options' require 'active_support/core_ext/kernel/singleton_class' require 'active_support/core_ext/module/delegation' require 'active_support/core_ext/array/extract_options' module ActiveSupport # Configurable provides a config method to store and retrieve # configuration options as an OrderedHash. module Configurable extend ActiveSupport::Concern class Configuration < ActiveSupport::InheritableOptions def compile_methods! self.class.compile_methods!(keys) end # compiles reader methods so we don't have to go through method_missing def self.compile_methods!(keys) keys.reject { |m| method_defined?(m) }.each do |key| class_eval <<-RUBY, __FILE__, __LINE__ + 1 def #{key}; _get(#{key.inspect}); end RUBY end end end module ClassMethods def config @_config ||= if respond_to?(:superclass) && superclass.respond_to?(:config) superclass.config.inheritable_copy else # create a new "anonymous" class that will host the compiled reader methods Class.new(Configuration).new end end def configure yield config end # Allows you to add shortcut so that you don't have to refer to attribute through config. # Also look at the example for config to contrast. # # class User # include ActiveSupport::Configurable # config_accessor :allowed_access # end # # user = User.new # user.allowed_access = true # user.allowed_access # => true # def config_accessor(*names) options = names.extract_options! names.each do |name| reader, line = "def #{name}; config.#{name}; end", __LINE__ writer, line = "def #{name}=(value); config.#{name} = value; end", __LINE__ singleton_class.class_eval reader, __FILE__, line singleton_class.class_eval writer, __FILE__, line class_eval reader, __FILE__, line unless options[:instance_reader] == false class_eval writer, __FILE__, line unless options[:instance_writer] == false end end end # Reads and writes attributes from a configuration OrderedHash. # # require 'active_support/configurable' # # class User # include ActiveSupport::Configurable # end # # user = User.new # # user.config.allowed_access = true # user.config.level = 1 # # user.config.allowed_access # => true # user.config.level # => 1 # def config @_config ||= self.class.config.inheritable_copy end end end