I'm trying to use the Zend_Controller_Plugin_ErrorHandler to handle my error 404 cases. According to the doc, the plugin has constants that one can use to match Exception types and handle them accordingly. e.g.

switch ($errors->type) {
        case Zend_Controller_Plugin_ErrorHandler::EXCEPTION_NO_ROUTE:
        case Zend_Controller_Plugin_ErrorHandler::EXCEPTION_NO_CONTROLLER:
        case Zend_Controller_Plugin_ErrorHandler::EXCEPTION_NO_ACTION:
            // 404 error -- controller or action not found

Herkes özellikle bu tür durumlar oluşturmak nasıl biliyor mu?