module Fix
  module Helper
    module OnHelper
      def on attribute, *args, &block
        unless instance_variable_defined? :@object
          raise MissingSubjectError,  "Incomplete specifications.  " \
                                      "Please specify a `subject` on the top."
        end

        @defs = {} unless instance_variable_defined? :@defs
        @args = [] unless instance_variable_defined? :@args

        i = On.new @object, @defs, *(@args + [[attribute] + args])
        i.instance_eval(&block)
      end
    end
  end
end

require_relative File.join '..', 'on'