如何在编程创建WooCommerce订单时正确应用优惠券折扣？

我在不使用购物车的情况下编程创建WooCommerce订单，其他功能正常，但应用优惠券后，折扣未体现在订单总额里。产品价格已显示折扣，但订单总价仍为原价。

当前代码 #

function create_order_with_pending_status_and_customer($email, $billing_link, $product_id, $quantity = 1, $coupon_code = "")
{
    if (!class_exists('WC_Order')) {
        return 'Error: WooCommerce not loaded.';
    }

    // Start session if not already started
    if (!session_id()) {
        session_start();
    }

    // Check if an order ID exists in the session
    if (isset($_SESSION['order_id'])) {
        $order_id = $_SESSION['order_id'];
        $order = wc_get_order($order_id);

        // Validate the order
        if ($order && $order->get_status() === 'pending') {
            foreach ($order->get_items() as $item) {
                if ($item->get_product_id() == $product_id) {
                    return $order_id; // Return existing order ID if product is already in the order
                }
            }
        }
    }

    // Get product details
    $product = wc_get_product($product_id);
    if (!$product || !$product->get_price()) {
        return 'Error: Product not found or invalid price.';
    }

    // Get or create customer
    $user = get_user_by('email', $email);
    if ($user) {
        $customer_id = $user->ID;
    } else {
        $customer_id = wc_create_new_customer($email, '', wp_generate_password());
        if (is_wp_error($customer_id)) {
            return 'Error creating customer: ' . $customer_id->get_error_message();
        }
    }

    // Calculate total price
    $total_price = $product->get_price() * $quantity;

    // Create a new WooCommerce order
    $order = wc_create_order();

    // Add product to the order
    $order->add_product($product, $quantity);

    // Set customer details
    $order->set_customer_id($customer_id);

    // Set billing details
    $billing_address = [
        'email' => $email,
    ];
    $order->set_address($billing_address, 'billing');

    // Add custom meta data
    $order->update_meta_data('billing_link', $billing_link);

    // Apply coupon code (if provided)
    if (!empty($coupon_code)) {
        $order->apply_coupon($coupon_code);
    }

    $order->calculate_totals();

    // Set order status
    $order->set_status('pending');

    // Set order total
    $order->set_total($total_price);

    // Save the order
    $order->save();

    // Store the order ID in the session
    $_SESSION['order_id'] = $order->get_id();

    return $order->get_id(); // Return the created Order ID
}

问题现象 #

• 产品原价：$24.99
• 折扣后产品单价：$16.24
• 订单总额仍显示：$24.99（预期为$16.24）

解决方案 #

问题根源是你手动调用$order->set_total($total_price);覆盖了calculate_totals()计算出的含折扣总价。calculate_totals()会自动处理优惠券折扣、税费等，手动设置总额会直接忽略这些计算结果。

修改步骤 #

1. 删除代码中手动设置订单总额的行：$order->set_total($total_price);
2. 保留$order->calculate_totals();在应用优惠券之后执行，让WooCommerce自动计算最终总额。

修改后的完整函数 #

function create_order_with_pending_status_and_customer($email, $billing_link, $product_id, $quantity = 1, $coupon_code = "")
{
    if (!class_exists('WC_Order')) {
        return 'Error: WooCommerce not loaded.';
    }

    // Start session if not already started
    if (!session_id()) {
        session_start();
    }

    // Check if an order ID exists in the session
    if (isset($_SESSION['order_id'])) {
        $order_id = $_SESSION['order_id'];
        $order = wc_get_order($order_id);

        // Validate the order
        if ($order && $order->get_status() === 'pending') {
            foreach ($order->get_items() as $item) {
                if ($item->get_product_id() == $product_id) {
                    return $order_id; // Return existing order ID if product is already in the order
                }
            }
        }
    }

    // Get product details
    $product = wc_get_product($product_id);
    if (!$product || !$product->get_price()) {
        return 'Error: Product not found or invalid price.';
    }

    // Get or create customer
    $user = get_user_by('email', $email);
    if ($user) {
        $customer_id = $user->ID;
    } else {
        $customer_id = wc_create_new_customer($email, '', wp_generate_password());
        if (is_wp_error($customer_id)) {
            return 'Error creating customer: ' . $customer_id->get_error_message();
        }
    }

    // Create a new WooCommerce order
    $order = wc_create_order();

    // Add product to the order
    $order->add_product($product, $quantity);

    // Set customer details
    $order->set_customer_id($customer_id);

    // Set billing details
    $billing_address = [
        'email' => $email,
    ];
    $order->set_address($billing_address, 'billing');

    // Add custom meta data
    $order->update_meta_data('billing_link', $billing_link);

    // Apply coupon code (if provided)
    if (!empty($coupon_code)) {
        $order->apply_coupon($coupon_code);
    }

    // Calculate totals including coupon discounts
    $order->calculate_totals();

    // Set order status
    $order->set_status('pending');

    // Save the order
    $order->save();

    // Store the order ID in the session
    $_SESSION['order_id'] = $order->get_id();

    return $order->get_id(); // Return the created Order ID
}

内容的提问来源于stack exchange，提问作者Robin Singh