
<?
    class Cart {
        var $basket = array();

        function addItem ($item, $qty) {
            if (isset($this->basket[$item])) {
                $this->basket[$item] += $qty;
            } else {
                $this->basket[$item] = $qty;
            }
        }

        function getBasket () {
            return $this->basket;
        }
    }

    session_start();
    if (!isset($_SESSION['cart'])) {
        $_SESSION['cart'] = new Cart;
    }

    if (isset($_POST['addtobasket'])) {
        $_SESSION['cart']->addItem($_POST['item'], $_POST['qty']);
    }
?>
<html>
    <head>
        <title> Shopping cart </title>
    </head>

    <body>
        <form action="<?= $_SERVER['PHP_SELF'] ?>" method="post">
            <input type="hidden" name="addtobasket" value="true" />
            item: <input type="text" name="item"><br />
            Quantity: <input type="text" name="qty"><br />
            <input type="submit" />
        </form>
        <?
            $basket = $_SESSION['cart']->getBasket();
            foreach ($basket as $item => $quantity) {
                print "<b>Item:</b> $item, <b>Quantity:</b> $quantity<br />";
            }
        ?>
    </body>
</html>