/**
  * @access public
  * @param array $root, the data root
  * @return string the processed template
  *
  */
 function process($root = array())
 {
     //process
     // something builtin
     $functions = ATBuiltIn::loadBuiltIns();
     extract($root);
     ob_start();
     include $this->source;
     $this->content = ob_get_contents();
     ob_end_clean();
     return $this->content;
 }
 /**
  *
  * @static
  * @access public
  * @return void
  */
 function loadBuiltIns()
 {
     // load all built in functions
     // 遍历builtin目录
     // 分别有PHP4/5方式 :p
     if (phpversion() > "5") {
         //
         include_once dirname(__FILE__) . "/ExtensionFilter.php";
         ATBuiltIn::load4PHP5();
     } else {
         //
         ATBuiltIn::load4PHP4();
     }
 }