Merge pull request #10816 from bogdan/less-dirty-dirty

Make AM::Dirty less dirty to plugin into AR or other library

3 files changed, 23 insertions, 12 deletions

diff --git a/activemodel/CHANGELOG.md b/activemodel/CHANGELOG.md
index 3d3c61ed1c..d9719afee3 100644
--- a/activemodel/CHANGELOG.md
+++ b/activemodel/CHANGELOG.md
@@ -1,3 +1,9 @@
+*   Added new API methods `reset_changes` and `changed_applied` to AM::Dirty
+    that control changes state. Previsously you needed to update internal
+    instance variables, but now API methods are available.
+
+    *Bogdan Gusiev*
+
 *   Fix has_secure_password. `password_confirmation` validations are triggered
     even if no `password_confirmation` is set.
 
diff --git a/activemodel/lib/active_model/dirty.rb b/activemodel/lib/active_model/dirty.rb
index ea5ddf71de..be2759b141 100644
--- a/activemodel/lib/active_model/dirty.rb
+++ b/activemodel/lib/active_model/dirty.rb
@@ -14,13 +14,7 @@ module ActiveModel
   #   track.
   # * Call <tt>attr_name_will_change!</tt> before each change to the tracked
   #   attribute.
-  #
-  # If you wish to also track previous changes on save or update, you need to
-  # add:
-  #
-  #   @previously_changed = changes
-  #
-  # inside of your save or update method.
+  # * Call <tt>changes_applied</tt> after the changes are persisted.
   #
   # A minimal implementation could be:
   #
@@ -39,8 +33,8 @@ module ActiveModel
   #     end
   #
   #     def save
-  #       @previously_changed = changes
-  #       @changed_attributes.clear
+  #       # do persistence work
+  #       changes_applied
   #     end
   #   end
   #
@@ -129,7 +123,7 @@ module ActiveModel
     #   person.save
     #   person.previous_changes # => {"name" => ["bob", "robert"]}
     def previous_changes
-      @previously_changed
+      @previously_changed ||= {}
     end
 
     # Returns a hash of the attributes with unsaved changes indicating their original
@@ -154,6 +148,18 @@ module ActiveModel
 
     private
 
+      # Removes current changes and makes them accessible through +previous_changes+.
+      def changes_applied
+        @previously_changed = changes
+        @changed_attributes = {}
+      end
+
+      # Removes all dirty data: current changes and previous changes
+      def reset_changes
+        @previously_changed = {}
+        @changed_attributes = {}
+      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 ba45089cca..ed34ca8a6e 100644
--- a/activemodel/test/cases/dirty_test.rb
+++ b/activemodel/test/cases/dirty_test.rb
@@ -29,8 +29,7 @@ class DirtyTest < ActiveModel::TestCase
     end
 
     def save
-      @previously_changed = changes
-      @changed_attributes.clear
+      changes_applied
     end
   end