<?php
   /* bootstrap class should be defined under ./application/Bootstrap.php */
   class Bootstrap extends Yaf_Bootstrap_Abstract {
        public function _initConfig(Yaf_Dispatcher $dispatcher) {
            var_dump(__METHOD__);
        }
        public function _initPlugin(Yaf_Dispatcher $dispatcher) {
            var_dump(__METHOD__);
        }
   }

   $config = array(
       "application" => array(
           "directory" => dirname(__FILE__) . "/application/",
       ),
   );
 
   $app = new Yaf_Application($config);
   $app->bootstrap();
?>

The above example will output something similar to: