class String unless method_defined?(:underscore) define_method :underscore do word = self.dup word.gsub!(/::/, '/') word.gsub!(/([A-Z]+)([A-Z][a-z])/,'\1_\2') word.gsub!(/([a-z\d])([A-Z])/,'\1_\2') word.tr!("-", "_") word.downcase! word end end end