Allow for the dirty tracking to work with the aliased name of aliased attributes.

Signed-off-by: Michael Koziarski <michael@koziarski.com>
[#812 state:committed]

1 files changed, 19 insertions, 1 deletions

diff --git a/activerecord/lib/active_record/dirty.rb b/activerecord/lib/active_record/dirty.rb
index 7e246e62ca..ae573799ae 100644
--- a/activerecord/lib/active_record/dirty.rb
+++ b/activerecord/lib/active_record/dirty.rb
@@ -34,8 +34,10 @@ module ActiveRecord
   #   person.name << 'by'
   #   person.name_change    # => ['uncle bob', 'uncle bobby']
   module Dirty
+    DIRTY_SUFFIXES = ['_changed?', '_change', '_will_change!', '_was']
+
     def self.included(base)
-      base.attribute_method_suffix '_changed?', '_change', '_will_change!', '_was'
+      base.attribute_method_suffix *DIRTY_SUFFIXES
       base.alias_method_chain :write_attribute, :dirty
       base.alias_method_chain :save,            :dirty
       base.alias_method_chain :save!,           :dirty
@@ -44,6 +46,8 @@ module ActiveRecord
 
       base.superclass_delegating_accessor :partial_updates
       base.partial_updates = true
+
+      base.send(:extend, ClassMethods)
     end
 
     # Do any attributes have unsaved changes?
@@ -161,5 +165,19 @@ module ActiveRecord
         old != value
       end
 
+    module ClassMethods
+      def self.extended(base)
+        base.metaclass.alias_method_chain(:alias_attribute, :dirty)
+      end
+
+      def alias_attribute_with_dirty(new_name, old_name)
+        alias_attribute_without_dirty(new_name, old_name)
+        DIRTY_SUFFIXES.each do |suffix|
+          module_eval <<-STR, __FILE__, __LINE__+1
+            def #{new_name}#{suffix}; self.#{old_name}#{suffix}; end
+          STR
+        end
+      end
+    end
   end
 end