when a representer module is extended we no longer set the @represent…

…able_attrs ivar directly but use a setter. this makes it work with mongoid and fixes trailblazer/roar#10.

lib/representable.rb

@@ -25,6 +25,8 @@
 #
 #   hero.extend(HeroRepresenter).to_json
 module Representable
+  attr_writer :representable_attrs
+
   def self.included(base)
     base.class_eval do
       extend ClassMethods
@@ -37,10 +39,7 @@ def self.included(base)
 
       # Copies the representable_attrs to the extended object.
       def self.extended(object)
-        attrs = representable_attrs
-        object.instance_eval do
-          @representable_attrs = attrs
-        end
+        object.representable_attrs=(representable_attrs)
       end
     end
   end

representable.gemspec

@@ -26,4 +26,5 @@ Gem::Specification.new do |s|
   s.add_development_dependency "test_xml"
   s.add_development_dependency "minitest", ">= 2.8.1"
   s.add_development_dependency "mocha"
+  s.add_development_dependency "mongoid"
 end

test/mongoid_test.rb

@@ -0,0 +1,31 @@
+require 'test_helper'
+require 'mongoid'
+require 'mongoid/document'
+
+class MongoidTest < MiniTest::Spec
+  describe "Mongoid compatibility" do
+    it "allows #to_json" do
+      class Profile
+        include Mongoid::Document
+        field :name
+      end
+
+      class Dude
+        include Mongoid::Document
+        embeds_one :profile, :class_name => "MongoidTest::Profile"
+      end
+
+      module ProfileRepresenter
+       include Representable::JSON
+
+       property :name
+      end
+
+      dude = Dude.new
+      dude.profile = Profile.new
+      dude.profile.name = "Kofi"
+
+      assert_equal "{\"name\":\"Kofi\"}", dude.profile.extend(ProfileRepresenter).to_json
+    end      
+  end
+end