Untitled

<?php
 
include_once '../autoloader.php';
session_start();
 
if(isset($_SESSION['customer'])) unset($_SESSION['customer']);
 
function EmptyString($str) {
    return !(isset($str) && (strlen(trim($str)) > 0)) && $str !== "0";
}
 
 
if(isset($_POST['submit-btn'])){
 
    unset($_POST['submit-btn']);
    $products = new Products;
 
    foreach($_POST as $key => $value){
        if(!EmptyString($_POST[$key]) && intval($value) >= 0) $products->setInfo($key, intval($value));
        else {
            header('Location: ../../order?err=emptyString:'.$key);
            $_POST = array();
            unset($products);
            exit();
        }
    }
 
    if(str_starts_with($products->validate(), "err#")){
        $error_msg = array_pop(explode("#", $products->validate()));
        header('Location: ../../order?err='.$error_msg);
        $_POST = array();
 
        exit();
    }
    else{
        $customer = new Customer;
        $customer->products_ordered = $products;
 
        $_SESSION['customer'] = serialize($customer);
        header('Location: ../../checkout');
        $_POST = array();
        exit();
    }
}
else{
    header('Location: ../../order?err=unvalidated');
    $_POST = array();
    exit();
}