add worklog sweeper

app/controllers/tasks_controller.rb

@@ -10,6 +10,7 @@ class TasksController < ApplicationController
 
   cache_sweeper :tag_sweeper, :only =>[:create, :update]
   cache_sweeper :task_sweeper
+  cache_sweeper :work_log_sweeper
 
   def index
     #TODO: Code smell, we should be dealing only with collections here

app/sweepers/work_log_sweeper.rb

@@ -0,0 +1,15 @@
+class WorkLogSweeper < ActionController::Caching::Sweeper
+  observe WorkLog
+
+  def after_update(log)
+    expire_fragment(["task_json", log.task])
+  end
+
+  def after_create(log)
+    expire_fragment(["task_json", log.task])
+  end
+
+  def after_destroy(log)
+    expire_fragment(["task_json", log.task])
+  end
+end