function is_item_added($user_id, $item_id)
{
global $db;
$cart_id = get_user_cart_id($user_id);
$query = "SELECT * FROM cart_item";
$query .= " WHERE cart_id = {$cart_id}";
$query .= " AND item_id = {$item_id}";
$results = mysqli_query($db, $query);
$result = mysqli_fetch_row($results);
if (empty($result)) {
return false;
}
mysqli_free_result($results);
return true;
}
<?php
if (!isset($_SESSION['id'])) {
// if not logged in , go register
redirect_to("register.php");
}
$cart_id = get_user_cart_id($_SESSION['id']);
// get the user cart
if (isset($_POST['update'])) {
$invalid_items = array();
$cart_items = $_POST;
foreach ($cart_items as $key => $quantity) {
if ($key === "update") {
break;
}
// reached last index (avoid breaking the app :D)
update_quantity($key, $quantity);
}
// clear the cart from invalid cart items with SORRY message (NOT IMPLEMENTED)
}
if (isset($_POST['checkout'])) {
$total_price = calculate_total_price($cart_id);
$user_credit = get_user_credit($_SESSION['id']);
if ($total_price > $user_credit) {
echo "Please Recharge , Credit not enough";
// error message (out of credit)
} else {
//get orders
$results = get_all_orders($cart_id);
//process each one
//invalid item array
