1 files changed, 34 insertions, 0 deletions
diff --git a/activerecord/lib/active_record/acts/touch.rb b/activerecord/lib/active_record/acts/touch.rb
new file mode 100644
index 0000000000..baf217542a
--- /dev/null
+++ b/activerecord/lib/active_record/acts/touch.rb
@@ -0,0 +1,34 @@
+module ActiveRecord
+  module Mixins
+    # Including this mixins will record when objects of the class are created in a datetime column called "created_at"
+    # and when its updated in another datetime column called "updated_at".
+    #
+    #   class Bill < ActiveRecord::Base
+    #     include ActiveRecord::Mixins::Touch
+    #   end
+    #
+    #   bill = Bill.create("amount" => 100)
+    #   bill.created_at # => Time.now at the moment of Bill.create
+    #   bill.updated_at # => Time.now at the moment of Bill.create
+    #
+    #   bill.update_attribute("amount", 150)
+    #   bill.created_at # => Time.now at the moment of Bill.create
+    #   bill.updated_at # => Time.now at the moment of bill.update_attribute
+    module Touch
+      def self.append_features(base)
+        super
+
+        base.before_create :touch_on_create
+        base.before_update :touch_on_update
+      end  
+
+      def touch_on_create
+        self.updated_at = (self.created_at ||= Time.now)
+      end
+
+      def touch_on_update
+        self.updated_at = Time.now
+      end
+    end
+  end
+end
+\ No newline at end of file