/**
  * event: controller_action_layout_render_before_ . $this->getFullActionName();
  * in: Mage_Core_Controller_Varien_Action::renderLayout()
  *
  * @param $event Varien_Event_Observer
  * @return void
  */
 public function addRobotsTagToIndexPage(Varien_Event_Observer $event)
 {
     $obj = new Varien_Object();
     $obj->setIndexHandle('cms_index_index');
     Mage::dispatchEvent('loewenstark_seo_robots_tag_to_index', array('object' => $obj, 'model' => $this));
     if (in_array($obj->getIndexHandle(), $this->_getLayout()->getUpdate()->getHandles())) {
         $this->_setRobotsHeader($this->_helper()->getDefaultRobots());
         $this->_setCanonicalHeader($this->_getBaseUrl());
     }
 }