Remove most code related to serialized properties

Nearly completely implemented in terms of custom properties.
`_before_type_cast` now stores the raw serialized string consistently,
which removes the need to keep track of "state". The following is now
consistently true:

- `model.serialized == model.reload.serialized`
- A model can be dumped and loaded infinitely without changing
- A model can be saved and reloaded infinitely without changing

3 files changed, 7 insertions, 58 deletions

diff --git a/activerecord/lib/active_record/attribute_methods/read.rb b/activerecord/lib/active_record/attribute_methods/read.rb
index 99b95b1fc4..ae3785638a 100644
--- a/activerecord/lib/active_record/attribute_methods/read.rb
+++ b/activerecord/lib/active_record/attribute_methods/read.rb
@@ -94,7 +94,7 @@ module ActiveRecord
 
         def cacheable_column?(column)
           if attribute_types_cached_by_default == ATTRIBUTE_TYPES_CACHED_BY_DEFAULT
-            ! serialized_attributes.include? column.name
+            true
           else
             attribute_types_cached_by_default.include?(column.type)
           end
diff --git a/activerecord/lib/active_record/attribute_methods/serialization.rb b/activerecord/lib/active_record/attribute_methods/serialization.rb
index e8a52719ef..425c33f2c6 100644
--- a/activerecord/lib/active_record/attribute_methods/serialization.rb
+++ b/activerecord/lib/active_record/attribute_methods/serialization.rb
@@ -76,21 +76,6 @@ module ActiveRecord
       module Behavior # :nodoc:
         extend ActiveSupport::Concern
 
-        module ClassMethods # :nodoc:
-          def initialize_attributes(attributes, options = {})
-            serialized = (options.delete(:serialized) { true }) ? :serialized : :unserialized
-            super(attributes, options)
-
-            serialized_attributes.each do |key, coder|
-              if attributes.key?(key)
-                attributes[key] = Type::Serialized::Attribute.new(coder, attributes[key], serialized)
-              end
-            end
-
-            attributes
-          end
-        end
-
         def should_record_timestamps?
           super || (self.record_timestamps && (attributes.keys & self.class.serialized_attributes.keys).present?)
         end
@@ -106,42 +91,6 @@ module ActiveRecord
             super
           end
         end
-
-        def read_attribute_before_type_cast(attr_name)
-          if self.class.serialized_attributes.include?(attr_name)
-            super.unserialized_value
-          else
-            super
-          end
-        end
-
-        def attributes_before_type_cast
-          super.dup.tap do |attributes|
-            self.class.serialized_attributes.each_key do |key|
-              if attributes.key?(key)
-                attributes[key] = attributes[key].unserialized_value
-              end
-            end
-          end
-        end
-
-        def typecasted_attribute_value(name)
-          if self.class.serialized_attributes.include?(name)
-            @raw_attributes[name].serialized_value
-          else
-            super
-          end
-        end
-
-        def attributes_for_coder
-          attribute_names.each_with_object({}) do |name, attrs|
-            attrs[name] = if self.class.serialized_attributes.include?(name)
-                            @raw_attributes[name].serialized_value
-                          else
-                            read_attribute_before_type_cast(name)
-                          end
-          end
-        end
       end
     end
   end
diff --git a/activerecord/lib/active_record/attribute_methods/write.rb b/activerecord/lib/active_record/attribute_methods/write.rb
index 3b9b9c81e8..c3e601a208 100644
--- a/activerecord/lib/active_record/attribute_methods/write.rb
+++ b/activerecord/lib/active_record/attribute_methods/write.rb
@@ -53,11 +53,11 @@ module ActiveRecord
       # specified +value+. Empty strings for fixnum and float columns are
       # turned into +nil+.
       def write_attribute(attr_name, value)
-        write_attribute_with_type_cast(attr_name, value, :type_cast_for_write)
+        write_attribute_with_type_cast(attr_name, value, true)
       end
 
       def raw_write_attribute(attr_name, value)
-        write_attribute_with_type_cast(attr_name, value, :raw_type_cast_for_write)
+        write_attribute_with_type_cast(attr_name, value, false)
       end
 
       private
@@ -66,7 +66,7 @@ module ActiveRecord
         write_attribute(attribute_name, value)
       end
 
-      def write_attribute_with_type_cast(attr_name, value, type_cast_method)
+      def write_attribute_with_type_cast(attr_name, value, should_type_cast)
         attr_name = attr_name.to_s
         attr_name = self.class.primary_key if attr_name == 'id' && self.class.primary_key
         @attributes.delete(attr_name)
@@ -78,9 +78,9 @@ module ActiveRecord
           @attributes[attr_name] = value
         end
 
-        if column
-          @raw_attributes[attr_name] = column.public_send(type_cast_method, value)
-        elsif @raw_attributes.has_key?(attr_name)
+        if column && should_type_cast
+          @raw_attributes[attr_name] = column.type_cast_for_write(value)
+        elsif !should_type_cast || @raw_attributes.has_key?(attr_name)
           @raw_attributes[attr_name] = value
         else
           raise ActiveModel::MissingAttributeError, "can't write unknown attribute `#{attr_name}'"