Magento에서 견적 및 주문에 사용자 정의 속성을 추가하는 방법은 무엇입니까?

<code class="php">public function catalogProductLoadAfter(Varien_Event_Observer $observer)
{
    // Get the product
    $product = $observer->getProduct();

    // Get the extra options
    $options = $action->getRequest()->getParam('extra_options');

    // Add the extra options to the product
    $additionalOptions = array();
    if ($additionalOption = $product->getCustomOption('additional_options')) {
        $additionalOptions = (array) unserialize($additionalOption->getValue());
    }
    foreach ($options as $key => $value) {
        $additionalOptions[] = array(
            'label' => $key,
            'value' => $value,
        );
    }
    $product->addCustomOption('additional_options', serialize($additionalOptions));
}</code>

<code class="php">public function salesConvertQuoteItemToOrderItem(Varien_Event_Observer $observer)
{
    // Get the quote item and order item
    $quoteItem = $observer->getItem();
    $orderItem = $observer->getOrderItem();

    // Get the additional options from the quote item
    $additionalOptions = $quoteItem->getOptionByCode('additional_options');

    // Set the additional options on the order item
    $options = $orderItem->getProductOptions();
    $options['additional_options'] = unserialize($additionalOptions->getValue());
    $orderItem->setProductOptions($options);
}</code>

<code class="php">// Get the product options
$options = $_item->getOptions();

// Check if additional_options is set
if (isset($options['additional_options'])) {
    // Get the additional options
    $additionalOptions = $options['additional_options'];

    // Add a placeholder row for the custom attribute
    echo '<tr>
        <td class="options label" title=""><span>' . $this->__('Custom Attribute') . '</span></td>
        <td class="options value" title="">
            <span>' . $additionalOptions[0]['value'] . '</span>
        </td>
    </tr>';
}</code>