Allow nil serialized attributes with a set class constraint. #7293 [sandofsky]

git-svn-id: http://svn-commit.rubyonrails.org/rails/trunk@6879 5ecf4fe2-1ee6-0310-87b1-e25e094e27de

activerecord/CHANGELOG

@@ -1,5 +1,7 @@
 *SVN*
 
+* Allow nil serialized attributes with a set class constraint.  #7293 [sandofsky]
+
 * Oracle: support binary fixtures.  #7987 [Michael Schoen]
 
 * Fixtures: pull fixture insertion into the database adapters.  #7987 [Michael Schoen]

activerecord/lib/active_record/base.rb

@@ -643,7 +643,7 @@ module ActiveRecord #:nodoc:
 
       # Specifies that the attribute by the name of +attr_name+ should be serialized before saving to the database and unserialized
       # after loading from the database. The serialization is done through YAML. If +class_name+ is specified, the serialized
-      # object must be of that class on retrieval or +SerializationTypeMismatch+ will be raised.
+      # object must be of that class on retrieval, or nil. Otherwise, +SerializationTypeMismatch+ will be raised.
       def serialize(attr_name, class_name = Object)
         serialized_attributes[attr_name.to_s] = class_name
       end
@@ -2110,7 +2110,7 @@ module ActiveRecord #:nodoc:
       def unserialize_attribute(attr_name)
         unserialized_object = object_from_yaml(@attributes[attr_name])
 
-        if unserialized_object.is_a?(self.class.serialized_attributes[attr_name])
+        if unserialized_object.is_a?(self.class.serialized_attributes[attr_name]) || unserialized_object.nil?
           @attributes[attr_name] = unserialized_object
         else
           raise SerializationTypeMismatch,

activerecord/test/base_test.rb

@@ -1154,16 +1154,29 @@ class BasicsTest < Test::Unit::TestCase
     assert_equal(myobj, topic.content)
   end
 
-  def test_serialized_attribute_with_class_constraint
+  def test_nil_serialized_attribute_with_class_constraint
     myobj = MyObject.new('value1', 'value2')
-    topic = Topic.create("content" => myobj)
+    topic = Topic.new
+    assert_nil topic.content
+  end
+
+  def test_should_raise_exception_on_serialized_attribute_with_type_mismatch
+    myobj = MyObject.new('value1', 'value2')
+    topic = Topic.new(:content => myobj)
+    assert topic.save
     Topic.serialize(:content, Hash)
-
     assert_raise(ActiveRecord::SerializationTypeMismatch) { Topic.find(topic.id).content }
+  ensure
+    Topic.serialize(:content)
+  end
 
+  def test_serialized_attribute_with_class_constraint
     settings = { "color" => "blue" }
-    Topic.find(topic.id).update_attribute("content", settings)
+    Topic.serialize(:content, Hash)
+    topic = Topic.new(:content => settings)
+    assert topic.save
     assert_equal(settings, Topic.find(topic.id).content)
+  ensure
     Topic.serialize(:content)
   end