require 'active_support/core_ext/array/extract_options' class Module def mattr_reader(*syms) options = syms.extract_options! syms.each do |sym| class_eval(<<-EOS, __FILE__, __LINE__ + 1) @@#{sym} = nil unless defined? @@#{sym} def self.#{sym} @@#{sym} end EOS unless options[:instance_reader] == false class_eval(<<-EOS, __FILE__, __LINE__ + 1) def #{sym} @@#{sym} end EOS end end end def mattr_writer(*syms) options = syms.extract_options! syms.each do |sym| class_eval(<<-EOS, __FILE__, __LINE__ + 1) def self.#{sym}=(obj) @@#{sym} = obj end EOS unless options[:instance_writer] == false class_eval(<<-EOS, __FILE__, __LINE__ + 1) def #{sym}=(obj) @@#{sym} = obj end EOS end end end # Extends the module object with module and instance accessors for class attributes, # just like the native attr* accessors for instance attributes. # # module AppConfiguration # mattr_accessor :google_api_key # self.google_api_key = "123456789" # # mattr_accessor :paypal_url # self.paypal_url = "www.sandbox.paypal.com" # end # # AppConfiguration.google_api_key = "overriding the api key!" def mattr_accessor(*syms) mattr_reader(*syms) mattr_writer(*syms) end end