public function Begin() {
$url = $_GET;
/**
* pseudocode:
* $url = split($_GET, '/');
* $controllerName = $url[0];
* $actionName = $url[1];
* $queryParams = $url[2...];
**/
$controllerFactory = new ControllerFactory();
$controller = $controllerFactory->CreateController($controllerName, $actionName);
$controller->OnActionExecuting();
$controller->ExecuteAction($queryParams);
$controller->OnActionExecuted();
}