1 files changed, 57 insertions, 0 deletions
diff --git a/activerecord/lib/active_record/type/serialized.rb b/activerecord/lib/active_record/type/serialized.rb
new file mode 100644
index 0000000000..4052ac0fa0
--- /dev/null
+++ b/activerecord/lib/active_record/type/serialized.rb
@@ -0,0 +1,57 @@
+module ActiveRecord
+  module Type
+    class Serialized < SimpleDelegator # :nodoc:
+      attr_reader :subtype, :coder
+
+      def initialize(subtype, coder)
+        @subtype = subtype
+        @coder = coder
+        super(subtype)
+      end
+
+      def type_cast(value)
+        if value.respond_to?(:unserialized_value)
+          value.unserialized_value(super(value.value))
+        else
+          super
+        end
+      end
+
+      def type_cast_for_write(value)
+        Attribute.new(coder, value, :unserialized)
+      end
+
+      def raw_type_cast_for_write(value)
+        Attribute.new(coder, value, :serialized)
+      end
+
+      def serialized?
+        true
+      end
+
+      def accessor
+        ActiveRecord::Store::IndifferentHashAccessor
+      end
+
+      class Attribute < Struct.new(:coder, :value, :state) # :nodoc:
+        def unserialized_value(v = value)
+          state == :serialized ? unserialize(v) : value
+        end
+
+        def serialized_value
+          state == :unserialized ? serialize : value
+        end
+
+        def unserialize(v)
+          self.state = :unserialized
+          self.value = coder.load(v)
+        end
+
+        def serialize
+          self.state = :serialized
+          self.value = coder.dump(value)
+        end
+      end
+    end
+  end
+end