Simplify AR configuration code.

Get rid of ActiveModel::Configuration, make better use of
ActiveSupport::Concern + class_attribute, etc.

1 files changed, 12 insertions, 0 deletions

diff --git a/activerecord/lib/active_record/serialization.rb b/activerecord/lib/active_record/serialization.rb
index 41e3b92499..e8dd312a47 100644
--- a/activerecord/lib/active_record/serialization.rb
+++ b/activerecord/lib/active_record/serialization.rb
@@ -1,9 +1,21 @@
 module ActiveRecord #:nodoc:
+  ActiveSupport.on_load(:active_record_config) do
+    mattr_accessor :include_root_in_json, instance_accessor: false
+    self.include_root_in_json = true
+  end
+
   # = Active Record Serialization
   module Serialization
     extend ActiveSupport::Concern
     include ActiveModel::Serializers::JSON
 
+    included do
+      singleton_class.class_eval do
+        remove_method :include_root_in_json
+        delegate :include_root_in_json, to: 'ActiveRecord::Model'
+      end
+    end
+
     def serializable_hash(options = nil)
       options = options.try(:clone) || {}