Add the order ID to the order item metadata before the order is saved and WooCommerce email notifications are sent

Question

I need to add a link with the order ID and a password to the order item metadata.

Currently, I am adding successfully other info to the item metadata with the woocommerce_checkout_create_order_line_item action, but when this action is running the order ID is not accessible yet (?).

Can I do this in another way, so the link will be added before the order is saved and a notification to the customer is sent?

add_action( 'woocommerce_checkout_create_order_line_item', 'custom_checkout_create_order_line_item', 20, 4 );
function custom_checkout_create_order_line_item( $item, $cart_item_key, $values, $order ) {
    if( ! isset( $values['test_title'] ) ) { return; }

    // add test info as order item metadata
    if( ! empty( $values['test_title'] ) ) {
        $test_pw = wp_generate_password(); // generate a password
        $item->update_meta_data( '_test_id', $values['test_id'] ); // add test id
        $item->update_meta_data( '_test_password', $test_pw ); // add test access password
        $item->update_meta_data( 'Access link', // add test access permalink
            get_permalink( $values['test_id'] ) . '?order=' . $order->get_id() . '&pw=' . $test_pw );
    }
}

Answer 1

Your hook is executed before the order is saved, and in that 'save' step the order id is determined.

So unless you could include this functionality in your hook I don't believe there is a way to know the order id at that point already.

However, from your question I understand that it concerns item meta data that you want to display in e-mails. So isn't it an option to use the woocommerce_order_item_meta_start or the woocommerce_order_item_meta_end hook that allows you to add additional product information before or after the output from the wc_display_item_meta() WooCommerce function:

function action_woocommerce_order_item_meta_start( $item_id, $item, $order, $plain_text ) {
    // On email notifications
    if ( ! is_wc_endpoint_url() && $item->is_type('line_item') ) {
        echo '<ul class="wc-item-meta"><li><strong class="wc-item-meta-label">Label</strong><p>Value order id = ' . $order->get_id() . '</p></li></ul>';
    }
}
add_action( 'woocommerce_order_item_meta_start', 'action_woocommerce_order_item_meta_start', 10, 4 );