Adding variable product attribute column in WooCommerce edit order page

Question

Based on Adding product attribute column to edit order page in Woocommerce answer code I wrote this function:

add_action( 'woocommerce_admin_order_item_headers', 'custom_admin_order_items_headers', 20, 1 );
function custom_admin_order_items_headers( $order ){

    echo '<th>';
    echo __('Marchio', 'woocommerce') . '</th>';
}

add_action('woocommerce_admin_order_item_values', 'my_woocommerce_admin_order_item_values', 10, 3);
function my_woocommerce_admin_order_item_values($_product, $item, $item_id = null) {

    $marchio = get_the_terms( $_product->post->ID, 'pa_marchio');
    echo '<td>' . $marchio[0]->name . '</td>';
}

It works for simple products but not with variable products, how can fix it?

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Answer 1

To get product ID use

$item->get_product_id()

Your function should look like this

add_action('woocommerce_admin_order_item_values', 'my_woocommerce_admin_order_item_values', 10, 3);
function my_woocommerce_admin_order_item_values($_product, $item, $item_id = null) {

    $marchio = get_the_terms( $item->get_product_id(), 'pa_marchio');
    echo '<td>' . $marchio[0]->name . '</td>';

}

Check this post for more information how to access orders Accessing Order Items protected data in Woocommerce 3