Add changelog entry

1 files changed, 34 insertions, 0 deletions

diff --git a/activesupport/CHANGELOG.md b/activesupport/CHANGELOG.md
index 10a25a120d..e789d7fa20 100644
--- a/activesupport/CHANGELOG.md
+++ b/activesupport/CHANGELOG.md
@@ -1,3 +1,37 @@
+*   Add "event object" support to the notification system.
+    Before this change, end users were forced to create hand made arsenal
+    event objects on their own, like this:
+
+        ActiveSupport::Notifications.subscribe('wait') do |*args|
+          @event = ActiveSupport::Notifications::Event.new(*args)
+        end
+        
+        ActiveSupport::Notifications.instrument('wait') do
+          sleep 1
+        end
+        
+        @event.duration # => 1000.138
+
+    After this change, if the block passed to `subscribe` only takes one
+    parameter, the framework will yield an event object to the block.  Now
+    end users are no longer required to make their own:
+
+        ActiveSupport::Notifications.subscribe('wait') do |event|
+          @event = event
+        end
+        
+        ActiveSupport::Notifications.instrument('wait') do
+          sleep 1
+        end
+        
+        p @event.allocations # => 7
+        p @event.cpu_time    # => 0.256
+        p @event.idle_time   # => 1003.2399
+
+    Now you can enjoy event objects without making them yourself.  Neat!
+
+    *Aaron "t.lo" Patterson*
+
 *   Add cpu_time, idle_time, and allocations to Event
 
     *Eileen M. Uchitelle*, *Aaron Patterson*