'[order-total-items]'); public $display_name = 'Products Quantity'; public function getValue($post, $field) { $order = $this->getOrder($post); if (!empty($order)) { $totalQuantity = 0; foreach ($order->get_items() as $item) { $totalQuantity += $item->get_quantity(); } } else { $totalQuantity = ''; } return $totalQuantity; } }