From e8573e527f1b9466b7d62ea69465a3b8f80f7238 Mon Sep 17 00:00:00 2001
From: James MacAulay <james@jadedpixel.com>
Date: Fri, 9 Apr 2010 12:29:28 -0400
Subject: [PATCH] add :root option to ActiveModel JSON serialization

---
 activemodel/lib/active_model/serializers/json.rb   |   23 ++++++++++++++++++-
 .../serializeration/json_serialization_test.rb     |   23 +++++++++++++++++++-
 activerecord/test/cases/json_serialization_test.rb |   20 +++++++++++++++++
 3 files changed, 63 insertions(+), 3 deletions(-)

diff --git a/activemodel/lib/active_model/serializers/json.rb b/activemodel/lib/active_model/serializers/json.rb
index 794de7d..bfb83e7 100644
--- a/activemodel/lib/active_model/serializers/json.rb
+++ b/activemodel/lib/active_model/serializers/json.rb
@@ -30,6 +30,19 @@ module ActiveModel
       #   # => {"id": 1, "name": "Konata Izumi", "age": 16,
       #         "created_at": "2006/08/01", "awesome": true}
       #
+      # The <tt>include_root_in_json</tt> setting can be overridden with the <tt>:root</tt>
+      # option to specify an arbitrary string as the top-level key, or to cancel the use of
+      # a root at all:
+      #
+      #   konata.to_json(:root => "person")
+      #   # => { "person": {"id": 1, "name": "Konata Izumi", "age": 16,
+      #                   "created_at": "2006/08/01", "awesome": true} }
+      #
+      #   ActiveRecord::Base.include_root_in_json = true
+      #   konata.to_json(:root => false)
+      #   # => {"id": 1, "name": "Konata Izumi", "age": 16,
+      #         "created_at": "2006/08/01", "awesome": true}
+      #
       # The remainder of the examples in this section assume include_root_in_json is set to
       # <tt>false</tt>.
       #
@@ -78,8 +91,14 @@ module ActiveModel
       #                   {"comments": [{"body": "Don't think too hard"}],
       #                    "title": "So I was thinking"}]}
       def encode_json(encoder)
-        hash = serializable_hash(encoder.options)
-        hash = { self.class.model_name.element => hash } if include_root_in_json
+        opts = encoder.options
+        hash = serializable_hash(opts)
+        root = if opts && opts.key?(:root)
+          opts[:root].to_s
+        elsif include_root_in_json
+          self.class.model_name.element
+        end
+        hash = { root => hash } if root
         ActiveSupport::JSON.encode(hash)
       end
 
diff --git a/activemodel/test/cases/serializeration/json_serialization_test.rb b/activemodel/test/cases/serializeration/json_serialization_test.rb
index 81df52f..cb031c4 100644
--- a/activemodel/test/cases/serializeration/json_serialization_test.rb
+++ b/activemodel/test/cases/serializeration/json_serialization_test.rb
@@ -21,7 +21,8 @@ class JsonSerializationTest < ActiveModel::TestCase
     @contact.preferences = { 'shows' => 'anime' }
   end
 
-  test "should include root in json" do
+  test "should include root in json from class setting" do
+    assert_no_match %r{^\{"[^"]*":\{}, @contact.to_json
     begin
       Contact.include_root_in_json = true
       json = @contact.to_json
@@ -37,6 +38,26 @@ class JsonSerializationTest < ActiveModel::TestCase
     end
   end
 
+  test "should include root in json from option" do
+    assert_no_match %r{^\{"[^"]*":\{}, @contact.to_json
+    assert_match %r{^\{"person":\{}, @contact.to_json(:root => 'person')
+    begin
+      Contact.include_root_in_json = true
+      assert_match %r{^\{"person":\{}, @contact.to_json(:root => 'person')
+    ensure
+      Contact.include_root_in_json = false
+    end
+  end
+
+  test "should not include root when option overrides class setting" do
+    begin
+      Contact.include_root_in_json = true
+      assert_no_match %r{^\{"[^"]*":\{}, @contact.to_json(:root => false)
+    ensure
+      Contact.include_root_in_json = false
+    end
+  end
+
   test "should encode all encodable attributes" do
     json = @contact.to_json
 
diff --git a/activerecord/test/cases/json_serialization_test.rb b/activerecord/test/cases/json_serialization_test.rb
index a3145d2..3e7c935 100644
--- a/activerecord/test/cases/json_serialization_test.rb
+++ b/activerecord/test/cases/json_serialization_test.rb
@@ -44,6 +44,26 @@ class JsonSerializationTest < ActiveRecord::TestCase
   ensure
     Contact.include_root_in_json = false
   end
+  
+  def test_should_include_root_in_json_from_option
+    assert_no_match %r{^\{"[^"]*":\{}, @contact.to_json
+    assert_match %r{^\{"person":\{}, @contact.to_json(:root => 'person')
+    begin
+      Contact.include_root_in_json = true
+      assert_match %r{^\{"person":\{}, @contact.to_json(:root => 'person')
+    ensure
+      Contact.include_root_in_json = false
+    end
+  end
+  
+  def test_should_not_include_root_when_option_overrides_class_setting
+    begin
+      Contact.include_root_in_json = true
+      assert_no_match %r{^\{"[^"]*":\{}, @contact.to_json(:root => false)
+    ensure
+      Contact.include_root_in_json = false
+    end
+  end
 
   def test_should_encode_all_encodable_attributes
     json = @contact.to_json
-- 
1.6.5.3