copy the columns hash to the active record instances, typecast using columns looked up on the instance

4 files changed, 66 insertions, 36 deletions

diff --git a/activerecord/lib/active_record/attribute_methods/read.rb b/activerecord/lib/active_record/attribute_methods/read.rb
index c129dc8c52..73e473391a 100644
--- a/activerecord/lib/active_record/attribute_methods/read.rb
+++ b/activerecord/lib/active_record/attribute_methods/read.rb
@@ -92,6 +92,8 @@ module ActiveRecord
         end
 
         def internal_attribute_access_code(attr_name, cast_code)
+          cast_code = instance_cast_code(attr_name)
+
           access_code = "v = @attributes.fetch(attr_name) { missing_attribute(attr_name, caller) };"
 
           access_code << "v && #{cast_code};"
@@ -116,6 +118,10 @@ module ActiveRecord
         def attribute_cast_code(attr_name)
           columns_hash[attr_name].type_cast_code('v')
         end
+
+        def instance_cast_code(attr_name)
+          "@columns_hash[attr_name].type_cast(v)"
+        end
       end
 
       # Returns the value of the attribute identified by <tt>attr_name</tt> after it has been typecast (for example,
@@ -124,10 +130,11 @@ module ActiveRecord
         self.class.type_cast_attribute(attr_name, @attributes, @attributes_cache)
       end
 
+
       private
-        def attribute(attribute_name)
-          read_attribute(attribute_name)
-        end
+      def attribute(attribute_name)
+        read_attribute(attribute_name)
+      end
     end
   end
 end
diff --git a/activerecord/lib/active_record/attribute_methods/serialization.rb b/activerecord/lib/active_record/attribute_methods/serialization.rb
index 0c8e4e4b9a..fbace73f7a 100644
--- a/activerecord/lib/active_record/attribute_methods/serialization.rb
+++ b/activerecord/lib/active_record/attribute_methods/serialization.rb
@@ -79,6 +79,14 @@ module ActiveRecord
             super
           end
         end
+
+        def instance_cast_code(attr_name)
+          if serialized_attributes.include?(attr_name)
+            "v.unserialized_value"
+          else
+            super
+          end
+        end
       end
 
       def type_cast_attribute_for_write(column, value)
diff --git a/activerecord/lib/active_record/attribute_methods/time_zone_conversion.rb b/activerecord/lib/active_record/attribute_methods/time_zone_conversion.rb
index 2f86e32f41..30ee0947b3 100644
--- a/activerecord/lib/active_record/attribute_methods/time_zone_conversion.rb
+++ b/activerecord/lib/active_record/attribute_methods/time_zone_conversion.rb
@@ -16,46 +16,59 @@ module ActiveRecord
 
       module ClassMethods
         protected
-          # The enhanced read method automatically converts the UTC time stored in the database to the time
-          # zone stored in Time.zone.
-          def attribute_cast_code(attr_name)
-            column = columns_hash[attr_name]
-
-            if create_time_zone_conversion_attribute?(attr_name, column)
-              typecast             = "v = #{super}"
-              time_zone_conversion = "v.acts_like?(:time) ? v.in_time_zone : v"
-
-              "((#{typecast}) && (#{time_zone_conversion}))"
-            else
-              super
-            end
+        # The enhanced read method automatically converts the UTC time stored in the database to the time
+        # zone stored in Time.zone.
+        def attribute_cast_code(attr_name)
+          column = columns_hash[attr_name]
+
+          if create_time_zone_conversion_attribute?(attr_name, column)
+            typecast             = "v = #{super}"
+            time_zone_conversion = "v.acts_like?(:time) ? v.in_time_zone : v"
+
+            "((#{typecast}) && (#{time_zone_conversion}))"
+          else
+            super
           end
+        end
 
-          # Defined for all +datetime+ and +timestamp+ attributes when +time_zone_aware_attributes+ are enabled.
-          # This enhanced write method will automatically convert the time passed to it to the zone stored in Time.zone.
-          def define_method_attribute=(attr_name)
-            if create_time_zone_conversion_attribute?(attr_name, columns_hash[attr_name])
-              method_body, line = <<-EOV, __LINE__ + 1
-                def #{attr_name}=(original_time)
-                  time = original_time
-                  unless time.acts_like?(:time)
-                    time = time.is_a?(String) ? Time.zone.parse(time) : time.to_time rescue time
-                  end
-                  time = time.in_time_zone rescue nil if time
-                  write_attribute(:#{attr_name}, original_time)
-                  @attributes_cache["#{attr_name}"] = time
+        # Defined for all +datetime+ and +timestamp+ attributes when +time_zone_aware_attributes+ are enabled.
+        # This enhanced write method will automatically convert the time passed to it to the zone stored in Time.zone.
+        def define_method_attribute=(attr_name)
+          if create_time_zone_conversion_attribute?(attr_name, columns_hash[attr_name])
+            method_body, line = <<-EOV, __LINE__ + 1
+              def #{attr_name}=(original_time)
+                time = original_time
+                unless time.acts_like?(:time)
+                  time = time.is_a?(String) ? Time.zone.parse(time) : time.to_time rescue time
                 end
-              EOV
-              generated_attribute_methods.module_eval(method_body, __FILE__, line)
-            else
-              super
-            end
+                time = time.in_time_zone rescue nil if time
+                write_attribute(:#{attr_name}, original_time)
+                @attributes_cache["#{attr_name}"] = time
+              end
+            EOV
+            generated_attribute_methods.module_eval(method_body, __FILE__, line)
+          else
+            super
           end
+        end
 
         private
-          def create_time_zone_conversion_attribute?(name, column)
-            time_zone_aware_attributes && !self.skip_time_zone_conversion_for_attributes.include?(name.to_sym) && column.type.in?([:datetime, :timestamp])
+        def instance_cast_code(attr_name)
+          column = columns_hash[attr_name]
+
+          if create_time_zone_conversion_attribute?(attr_name, column)
+            typecast             = "v = #{super}"
+            time_zone_conversion = "v.acts_like?(:time) ? v.in_time_zone : v"
+
+            "((#{typecast}) && (#{time_zone_conversion}))"
+          else
+            super
           end
+        end
+
+        def create_time_zone_conversion_attribute?(name, column)
+          time_zone_aware_attributes && !self.skip_time_zone_conversion_for_attributes.include?(name.to_sym) && column.type.in?([:datetime, :timestamp])
+        end
       end
     end
   end
diff --git a/activerecord/lib/active_record/core.rb b/activerecord/lib/active_record/core.rb
index a2ce620354..93b8e269fb 100644
--- a/activerecord/lib/active_record/core.rb
+++ b/activerecord/lib/active_record/core.rb
@@ -341,6 +341,8 @@ module ActiveRecord
 
       @attributes[pk] = nil unless @attributes.key?(pk)
 
+      @columns_hash = self.class.columns_hash.dup
+
       @relation               = nil
       @aggregation_cache      = {}
       @association_cache      = {}