From 1482081766d3ccac9930bb1f013776d1fbe7289a Mon Sep 17 00:00:00 2001
From: Gosha Arinich <me@goshakkk.name>
Date: Sun, 5 May 2013 10:35:44 +0300
Subject: [PATCH] add support of mongoid collection serialization

---
 README.md                       | 12 ++++++++----
 lib/active_model_serializers.rb | 16 ++++++++--------
 test/serializer_support_test.rb | 10 ++++++++++
 3 files changed, 26 insertions(+), 12 deletions(-)

diff --git a/README.md b/README.md
index 41214c72..efd998e3 100644
--- a/README.md
+++ b/README.md
@@ -48,10 +48,14 @@ $ rails g serializer post
 ### Support for PORO's and other ORM's.
 
 Currently `ActiveModel::Serializers` adds serialization support to all models
-that descend from `ActiveRecord`. If you are using another ORM, or if you are
-using objects that are `ActiveModel` compliant but do not descend from
-`ActiveRecord`, you must add an include statement for
-`ActiveModel::SerializerSupport`.
+that descend from `ActiveRecord` or include `Mongoid::Document`. If you are
+using another ORM, or if you are using objects that are `ActiveModel`
+compliant but do not descend from `ActiveRecord` or include
+`Mongoid::Document`, you must add an include statement for
+`ActiveModel::SerializerSupport` to make models serializable. If you
+also want to make collections serializable, you should include
+`ActiveModel::ArraySerializationSupport` into your ORM's
+relation/criteria class.
 
 # ActiveModel::Serializer
 
diff --git a/lib/active_model_serializers.rb b/lib/active_model_serializers.rb
index 95a931b9..a708585c 100644
--- a/lib/active_model_serializers.rb
+++ b/lib/active_model_serializers.rb
@@ -64,12 +64,6 @@ module ActiveModel::SerializerSupport
   alias :read_attribute_for_serialization :send
 end
 
-[:active_record, :mongoid].each do |orm|
-  ActiveSupport.on_load(orm) do
-    include ActiveModel::SerializerSupport
-  end
-end
-
 module ActiveModel::ArraySerializerSupport
   def active_model_serializer
     ActiveModel::ArraySerializer
@@ -79,8 +73,14 @@ end
 Array.send(:include, ActiveModel::ArraySerializerSupport)
 Set.send(:include, ActiveModel::ArraySerializerSupport)
 
-ActiveSupport.on_load(:active_record) do
-  ActiveRecord::Relation.send(:include, ActiveModel::ArraySerializerSupport)
+{
+  :active_record => 'ActiveRecord::Relation',
+  :mongoid => 'Mongoid::Criteria'
+}.each do |orm, rel_class|
+  ActiveSupport.on_load(orm) do
+    include ActiveModel::SerializerSupport
+    rel_class.constantize.send(:include, ActiveModel::ArraySerializerSupport)
+  end
 end
 
 begin
diff --git a/test/serializer_support_test.rb b/test/serializer_support_test.rb
index e82f1fb1..03bd130f 100644
--- a/test/serializer_support_test.rb
+++ b/test/serializer_support_test.rb
@@ -20,6 +20,11 @@ module ActiveRecord
   end
 end
 
+module Mongoid
+  class Criteria
+  end
+end
+
 class SerializerSupportTest < ActiveModel::TestCase
   test "it returns nil if no serializer exists" do
     assert_equal nil, RandomModel.new.active_model_serializer
@@ -37,5 +42,10 @@ class SerializerSupportTest < ActiveModel::TestCase
     ActiveSupport.run_load_hooks(:active_record)
     assert_equal ActiveModel::ArraySerializer, ActiveRecord::Relation.new.active_model_serializer
   end
+
+  test "it automatically includes array_serializer in mongoid/criteria" do
+    ActiveSupport.run_load_hooks(:mongoid)
+    assert_equal ActiveModel::ArraySerializer, Mongoid::Criteria.new.active_model_serializer
+  end
 end