Observer refactored to use StateMachine events

app/observers/activity_observer.rb

@@ -20,15 +20,23 @@ class ActivityObserver < ActiveRecord::Observer
     end
   end
 
-  def after_save(record)
-    if record.changed.include?("closed") && record.author_id_of_changes
+  def after_close(record, transition)
       Event.create(
         project: record.project,
         target_id: record.id,
         target_type: record.class.name,
-        action: (record.closed ? Event::CLOSED : Event::REOPENED),
+        action: Event::CLOSED,
         author_id: record.author_id_of_changes
       )
   end
+
+  def after_reopen(record, transition)
+      Event.create(
+        project: record.project,
+        target_id: record.id,
+        target_type: record.class.name,
+        action: Event::REOPENED,
+        author_id: record.author_id_of_changes
+      )
   end
 end