Track changed attributes

lib/globalize-accessors.rb

@@ -30,12 +30,28 @@ def define_getter(attr_name, locale)
     define_method localized_attr_name_for(attr_name, locale) do
       globalize.stash.contains?(locale, attr_name) ? globalize.send(:fetch_stash, locale, attr_name) : globalize.send(:fetch_attribute, locale, attr_name)
     end
+
+    define_method "#{localized_attr_name_for(attr_name, locale)}_was" do
+      self.attribute_was(localized_attr_name_for(attr_name, locale))
+    end
   end
 
   def define_setter(attr_name, locale)
     localized_attr_name = localized_attr_name_for(attr_name, locale)
 
     define_method :"#{localized_attr_name}=" do |value|
+      # custom dirty tracking to enable #{attr_name}_was, taken from globalize/rails
+      if attribute_changed?(localized_attr_name)
+        # If there's already a change, delete it if this undoes the change.
+        old = changed_attributes[localized_attr_name]
+        @changed_attributes.delete(localized_attr_name) if value == old
+      else
+        # If there's not a change yet, record it.
+        old = globalize.fetch(locale, attr_name)
+        old = old.dup if old.duplicable?
+        @changed_attributes[localized_attr_name] = old if value != old
+      end
+
       write_attribute(attr_name, value, :locale => locale)
       translation_for(locale)[attr_name] = value
     end

readme.md

@@ -26,7 +26,7 @@ class Product
 end
 ````
 
-Gives you access to methods: `title_pl`, `title_en`, `title_pl=`, `title_en=`. These work seamlessly with Globalize (not even touching the "core" `title`, `title=` methods used by Globalize itself).
+Gives you access to methods: `title_pl`, `title_en`, `title_pl=`, `title_en=`, `title_en_was`, `title_pl_was`. These work seamlessly with Globalize (not even touching the "core" `title`, `title=` methods used by Globalize itself).
 
 The `:locales` and `:attributes` options are optional. Their default values are:
 

test/globalize_accessors_test.rb

@@ -51,6 +51,9 @@ class UnitWithoutAccessors < ActiveRecord::Base
     assert_equal "Name en",  u.name_en
     assert_equal "Title pl", u.title_pl
 
+    assert_equal nil, u.name_en_was
+    assert_equal nil, u.title_pl_was
+
     assert_nil u.name_pl
     assert_nil u.title_en
   end
@@ -98,6 +101,10 @@ class UnitWithoutAccessors < ActiveRecord::Base
 
     u.name_pl = "Name pl"
     u.name_en = "Name en2"
+
+    assert_equal "Name en",   u.name_en_was
+    assert_equal nil,         u.name_pl_was
+
     u.save!
 
     assert_equal "Name en2",  u.name