4 files changed, 62 insertions, 0 deletions
diff --git a/actionpack/lib/action_controller.rb b/actionpack/lib/action_controller.rb
index f4eaa2fd1b..3829e60bb0 100644
--- a/actionpack/lib/action_controller.rb
+++ b/actionpack/lib/action_controller.rb
@@ -31,6 +31,7 @@ module ActionController
     autoload :RequestForgeryProtection
     autoload :Rescue
     autoload :Responder
+    autoload :Serialization
     autoload :SessionManagement
     autoload :Streaming
     autoload :Testing
diff --git a/actionpack/lib/action_controller/base.rb b/actionpack/lib/action_controller/base.rb
index 98bfe72fef..cfb9cf5e6e 100644
--- a/actionpack/lib/action_controller/base.rb
+++ b/actionpack/lib/action_controller/base.rb
@@ -190,6 +190,7 @@ module ActionController
       Redirecting,
       Rendering,
       Renderers::All,
+      Serialization,
       ConditionalGet,
       RackDelegation,
       SessionManagement,
diff --git a/actionpack/lib/action_controller/metal/serialization.rb b/actionpack/lib/action_controller/metal/serialization.rb
new file mode 100644
index 0000000000..9bb665a9ae
--- /dev/null
+++ b/actionpack/lib/action_controller/metal/serialization.rb
@@ -0,0 +1,26 @@
+module ActionController
+  module Serialization
+    extend ActiveSupport::Concern
+
+    include ActionController::Renderers
+
+    included do
+      class_attribute :_serialization_scope
+    end
+
+    def serialization_scope
+      send(_serialization_scope)
+    end
+
+    def _render_option_json(json, options)
+      json = json.active_model_serializer.new(json, serialization_scope) if json.respond_to?(:active_model_serializer)
+      super
+    end
+
+    module ClassMethods
+      def serialization_scope(scope)
+        self._serialization_scope = scope
+      end
+    end
+  end
+end
diff --git a/actionpack/test/controller/render_json_test.rb b/actionpack/test/controller/render_json_test.rb
index fc604a2db3..f886af1a95 100644
--- a/actionpack/test/controller/render_json_test.rb
+++ b/actionpack/test/controller/render_json_test.rb
@@ -15,9 +15,32 @@ class RenderJsonTest < ActionController::TestCase
     end
   end
 
+  class JsonSerializer
+    def initialize(object, scope)
+      @object, @scope = object, scope
+    end
+
+    def as_json(*)
+      { :object => @object.as_json, :scope => @scope.as_json }
+    end
+  end
+
+  class JsonSerializable
+    def active_model_serializer
+      JsonSerializer
+    end
+
+    def as_json(*)
+      { :serializable_object => true }
+    end
+  end
+
   class TestController < ActionController::Base
     protect_from_forgery
 
+    serialization_scope :current_user
+    attr_reader :current_user
+
     def self.controller_path
       'test'
     end
@@ -61,6 +84,11 @@ class RenderJsonTest < ActionController::TestCase
     def render_json_without_options
       render :json => JsonRenderable.new
     end
+
+    def render_json_with_serializer
+      @current_user = Struct.new(:as_json).new(:current_user => true)
+      render :json => JsonSerializable.new
+    end
   end
 
   tests TestController
@@ -132,4 +160,10 @@ class RenderJsonTest < ActionController::TestCase
     get :render_json_without_options
     assert_equal '{"a":"b"}', @response.body
   end
+
+  def test_render_json_with_serializer
+    get :render_json_with_serializer
+    assert_match '"scope":{"current_user":true}', @response.body
+    assert_match '"object":{"serializable_object":true}', @response.body
+  end
 end