Custom Fields in (shipping) invoice

if(empty($this->order->order_shipping_method) && empty($this->order->shippings)) {
	echo '- <em>'.JText::_('NONE').'</em>';
} else if(!empty($this->order->order_shipping_method)) {
	if(!is_numeric($this->order->order_shipping_id)){
		$shipping_name = $this->getShippingName($this->order->order_shipping_method, $this->order->order_shipping_id);
		echo ' - ' . $shipping_name;
	}else{
		$shipping = $this->shippingClass->get($this->order->order_shipping_id);
		echo ' - ' . $shipping->shipping_name;
	}
} else {
	// Multi shipping display
}

function getShippingName($shipping_method, $shipping_id) {
	$shipping_name = $shipping_method . ' ' . $shipping_id;
	if(strpos($shipping_id, '-') !== false) {
		$shipping_ids = explode('-', $shipping_id, 2);
		$shipping = $this->shippingClass->get($shipping_ids[0]);
		if(!empty($shipping->shipping_params) && is_string($shipping->shipping_params))
			$shipping->shipping_params = unserialize($shipping->shipping_params);
		$shippingMethod = hikashop_import('hikashopshipping', $shipping_method);
		$methods = $shippingMethod->shippingMethods($shipping);
			if(isset($methods[$shipping_id])){
			$shipping_name = $shipping->shipping_name.' - '.$methods[$shipping_id];
		}else{
			$shipping_name = $shipping_id;
		}
	}
	return $shipping_name;
}