PHP CD::reset 예제들

if (empty($_SESSION['cd_list'])) {
    $_SESSION['cd_list'] = array();
}
$app = new Silex\Application();
// $app['debug'] = true;
$app->register(new Silex\Provider\TwigServiceProvider(), array('twig.path' => __DIR__ . '/../views'));
$app->get("/", function () use($app) {
    return $app['twig']->render('display.html.twig');
});
$app->post("/show", function () use($app) {
    $cd = new CD($_POST['title'], new Artist($_POST['artist']));
    $cd->save();
    return $app['twig']->render('display.html.twig', array('cds' => CD::getAll()));
});
$app->post("/clear", function () use($app) {
    CD::reset();
    return $app['twig']->render('display.html.twig', array('cds' => CD::getAll()));
});
$app->get("/cd_search", function () use($app) {
    $cds = CD::getAll();
    $search_return = array();
    $search = strtolower($_GET['artist']);
    foreach ($cds as $cd) {
        $this_artist = $cd->getArtist();
        $artist = strtolower($this_artist->getName());
        if ($cd->matchArtist($artist, $search)) {
            array_push($search_return, $cd);
        }
    }
    return $app['twig']->render('displaysearch.html.twig', array('cds' => $search_return));
});