public static function get_instance()
 {
     if (self::$instance === null) {
         self::$instance = new QHShopSession();
     }
     return self::$instance;
 }
 public static function run()
 {
     $instance = self::get_instance();
     //start session
     QHShopSession::run();
     //start qhshop proudct
     QHShopProduct::run();
     //start shortcode
     QHShopShortCode::run();
     //start setting
     QHShopSetting::run();
     //run widget cart
     QHShopWidgetCart::run();
     //khoi dong order
     QHShopOrder::run();
     //run widget category
     QHShopWidgetCategory::run();
     return $instance;
 }
 public static function save_order()
 {
     if (isset($_POST['checkout'])) {
         $cart = QHShopSession::get('cart');
         if ($cart) {
             $post_id = wp_insert_post(array('post_status' => 'private', 'post_type' => 'product_order', 'post_title' => ' ;', 'post_content' => ' ', 'post_excerpt' => ' '), true);
             update_post_meta($post_id, 'order', array('checkout' => $_POST['checkout'], 'cart' => $cart, 'status' => 0));
             QHShopSession::destroy('cart');
             wp_redirect(get_permalink(get_page_by_path('shop')));
         }
     }
 }
 public static function delete_cart_ajax()
 {
     $json['status'] = 0;
     if (isset($_POST['item_id']) && !empty($_POST['item_id'])) {
         $cart = QHShopSession::get('cart');
         $option = get_option('qhshop_setting');
         if (!empty($cart)) {
             QHShopSession::destroy($_POST['item_id']);
             $total = 0;
             foreach ($cart as $item) {
                 $total += $item['item_quantity'] * $item['item_price'];
             }
             $json['subtotal'] = QHShopTool::get_currency($total, $option);
             $json['status'] = 1;
         }
     }
     wp_send_json_success($json);
 }