Using acts_as_journalized if available

This is not tested - it was just introduced to reduce the degree of being broken

app/models/cost_object.rb

@@ -17,9 +17,15 @@ class CostObject < ActiveRecord::Base
   acts_as_event :title => Proc.new {|o| "#{l(:label_cost_object)} ##{o.id}: #{o.subject}"},
                 :url => Proc.new {|o| {:controller => 'cost_objects', :action => 'show', :id => o.id}}
   
-  acts_as_activity_provider :find_options => {:include => [:project, :author]},
-                            :timestamp => "#{table_name}.updated_on",
-                            :author_key => :author_id
+  if respond_to? :acts_as_journalized
+    acts_as_journalized :activity_find_options => {:include => [:project, :author]},
+                        :activity_timestamp => "#{table_name}.updated_on",
+                        :activity_author_key => :author_id
+  else
+    acts_as_activity_provider :find_options => {:include => [:project, :author]},
+                              :timestamp => "#{table_name}.updated_on",
+                              :author_key => :author_id
+  end
   
   validates_presence_of :subject, :project, :author, :kind
   validates_length_of :subject, :maximum => 255
@@ -148,4 +154,4 @@ class CostObject < ActiveRecord::Base
     return "issue cost_object"
   end
   
-end
+end