/**
  * Visit a Navigation Block
  * 
  * @param object NavBlockSiteComponent $siteComponent
  * @return mixed
  * @access public
  * @since 6/11/08
  */
 public function visitNavBlock(NavBlockSiteComponent $siteComponent)
 {
     $orig = $siteComponent->getDisplayName();
     $new = $this->replacePlaceholders($orig);
     if ($orig != $new) {
         $siteComponent->updateDisplayName($new);
     }
     $orig = $siteComponent->getDescription();
     $new = $this->replacePlaceholders($orig);
     if ($orig != $new) {
         $siteComponent->updateDescription($new);
     }
     // Traverse down
     $childOrganizer = $siteComponent->getOrganizer();
     $childOrganizer->acceptVisitor($this);
     $nestedMenuOrganizer = $siteComponent->getNestedMenuOrganizer();
     if (!is_null($nestedMenuOrganizer)) {
         $nestedMenuOrganizer->acceptVisitor($this);
     }
 }