Added rollback method to ActiveModel::Dirty

2 files changed, 35 insertions, 0 deletions

diff --git a/activemodel/lib/active_model/dirty.rb b/activemodel/lib/active_model/dirty.rb
index 98ffffeb10..3e0d7f9115 100644
--- a/activemodel/lib/active_model/dirty.rb
+++ b/activemodel/lib/active_model/dirty.rb
@@ -17,6 +17,7 @@ module ActiveModel
   # * Call <tt>changes_applied</tt> after the changes are persisted.
   # * Call <tt>reset_changes</tt> when you want to reset the changes
   #   information.
+  # * Call <tt>rollback_changes</tt> when you want to restore previous data
   #
   # A minimal implementation could be:
   #
@@ -42,6 +43,10 @@ module ActiveModel
   #     def reload!
   #       reset_changes
   #     end
+  #
+  #     def rollback!
+  #       rollback_changes
+  #     end
   #   end
   #
   # A newly instantiated object is unchanged:
@@ -72,6 +77,13 @@ module ActiveModel
   #   person.reload!
   #   person.previous_changes # => {}
   #
+  # Rollback the changes:
+  #
+  #   person.name = "Uncle Bob"
+  #   person.rollback!
+  #   person.name           # => "Bill"
+  #   person.name_changed?  # => false
+  #
   # Assigning the same value leaves the attribute unchanged:
   #
   #   person.name = 'Bill'
@@ -176,6 +188,11 @@ module ActiveModel
         @changed_attributes = ActiveSupport::HashWithIndifferentAccess.new
       end
 
+      # Restore all previous data
+      def rollback_changes #:doc:
+        changed_attributes.each_key { |attr| reset_attribute! attr }
+      end
+
       # Handle <tt>*_change</tt> for +method_missing+.
       def attribute_change(attr)
         [changed_attributes[attr], __send__(attr)] if attribute_changed?(attr)
diff --git a/activemodel/test/cases/dirty_test.rb b/activemodel/test/cases/dirty_test.rb
index 2853476c91..d39484a7b9 100644
--- a/activemodel/test/cases/dirty_test.rb
+++ b/activemodel/test/cases/dirty_test.rb
@@ -45,6 +45,10 @@ class DirtyTest < ActiveModel::TestCase
     def reload
       reset_changes
     end
+
+    def rollback
+      rollback_changes
+    end
   end
 
   setup do
@@ -176,4 +180,18 @@ class DirtyTest < ActiveModel::TestCase
     assert_equal ActiveSupport::HashWithIndifferentAccess.new, @model.previous_changes
     assert_equal ActiveSupport::HashWithIndifferentAccess.new, @model.changed_attributes
   end
+
+  test "rollback should restore all previous data" do
+    @model.name = 'Dmitry'
+    @model.color = 'Red'
+    @model.save
+    @model.name = 'Bob'
+    @model.color = 'White'
+
+    @model.rollback
+
+    assert_not @model.changed?
+    assert_equal 'Dmitry', @model.name
+    assert_equal 'Red', @model.color
+  end
 end