Add support for root keys

lib/action_controller/serialization.rb

@@ -12,7 +12,7 @@ module Serialization
 
         if serializer
           # omg hax
-          object = serializer.new(resource)
+          object = serializer.new(resource, options)
           adapter = ActiveModel::Serializer.adapter.new(object)
 
           super(adapter, options)

lib/active_model/serializer.rb

@@ -73,12 +73,12 @@ def self.serializer_for(resource)
 
     def self.adapter
       adapter_class = case config.adapter
-                      when Symbol
-                        class_name = "ActiveModel::Serializer::Adapter::#{config.adapter.to_s.classify}"
-                        class_name.safe_constantize
-                      when Class
-                        config.adapter
-                      end
+      when Symbol
+        class_name = "ActiveModel::Serializer::Adapter::#{config.adapter.to_s.classify}"
+        class_name.safe_constantize
+      when Class
+        config.adapter
+      end
       unless adapter_class
         valid_adapters = Adapter.constants.map { |klass| ":#{klass.to_s.downcase}" }
         raise ArgumentError, "Unknown adapter: #{config.adapter}. Valid adapters are: #{valid_adapters}"
@@ -87,10 +87,31 @@ def self.adapter
       adapter_class
     end
 
-    attr_accessor :object
+    def self._root
+      @@root ||= false
+    end
+
+    def self._root=(root)
+      @@root = root
+    end
+
+    def self.root_name
+      name.demodulize.underscore.sub(/_serializer$/, '') if name
+    end
 
-    def initialize(object)
+    attr_accessor :object, :root
+
+    def initialize(object, options = {})
       @object = object
+      @root   = options[:root] || (self.class._root ? self.class.root_name : false)
+    end
+
+    def json_key
+      if root == true || root.nil?
+        self.class.root_name
+      else
+        root
+      end
     end
 
     def attributes(options = {})

lib/active_model/serializer/adapter.rb

@@ -8,16 +8,22 @@ class Adapter
 
       attr_reader :serializer
 
-      def initialize(serializer)
+      def initialize(serializer, options = {})
         @serializer = serializer
       end
 
       def serializable_hash(options = {})
         raise NotImplementedError, 'This is an abstract method. Should be implemented at the concrete adapter.'
       end
 
-      def to_json(options={})
-        serializable_hash(options).to_json
+      def to_json(options = {})
+        result = serializable_hash(options)
+
+        if root = options.fetch(:root, serializer.json_key)
+          result = { root => result }
+        end
+
+        result.to_json
       end
     end
   end

lib/active_model/serializer/adapter/json.rb

@@ -13,6 +13,7 @@ def serializable_hash(options = {})
               @hash[name] = association.attributes(options)
             end
           end
+
           @hash
         end
       end

test/action_controller/serialization_test.rb

@@ -5,7 +5,13 @@ module Serialization
     class ImplicitSerializerTest < ActionController::TestCase
       class MyController < ActionController::Base
         def render_using_implicit_serializer
-          render json: Profile.new({ name: 'Name 1', description: 'Description 1', comments: 'Comments 1' })
+          @profile = Profile.new({ name: 'Name 1', description: 'Description 1', comments: 'Comments 1' })
+          render json: @profile
+        end
+
+        def render_using_custom_root
+          @profile = Profile.new({ name: 'Name 1', description: 'Description 1', comments: 'Comments 1' })
+          render json: @profile, root: "custom_root"
         end
       end
 
@@ -18,8 +24,13 @@ def test_render_using_implicit_serializer
         assert_equal 'application/json', @response.content_type
         assert_equal '{"name":"Name 1","description":"Description 1"}', @response.body
       end
+
+      def test_render_using_custom_root
+        get :render_using_custom_root
+
+        assert_equal 'application/json', @response.content_type
+        assert_equal '{"custom_root":{"name":"Name 1","description":"Description 1"}}', @response.body
+      end
     end
   end
 end
-
-