在 WooCommerce 中以编程方式将礼品产品变体自动添加到购物车？

Question

当有人将产品添加到购物车时，我正在尝试为 woocommerce 创建买一送一优惠。下面的代码有效，但仅适用于简单的产品，我尝试将变体 ID 添加到变量中，但它不起作用。有任何想法吗？感谢社区

add_action( 'template_redirect', 'bbloomer_add_gift_if_id_in_cart' );
 
function bbloomer_add_gift_if_id_in_cart() {
 
   if ( is_admin() ) return;
   if ( WC()->cart->is_empty() ) return;
 
   $product_bought_id = 421;
   $product_gifted_id = 1256;
 
   // see if product id in cart
   $product_bought_cart_id = WC()->cart->generate_cart_id( $product_bought_id );
   $product_bought_in_cart = WC()->cart->find_product_in_cart( $product_bought_cart_id );
 
   // see if gift id in cart
   $product_gifted_cart_id = WC()->cart->generate_cart_id( $product_gifted_id );
   $product_gifted_in_cart = WC()->cart->find_product_in_cart( $product_gifted_cart_id );
 
   // if not in cart remove gift, else add gift
   if ( ! $product_bought_in_cart ) {
      if ( $product_gifted_in_cart ) WC()->cart->remove_cart_item( $product_gifted_in_cart );
   } else {
      if ( ! $product_gifted_in_cart ) WC()->cart->add_to_cart( $product_gifted_id );
   }
}

Answer 1

要将产品变体添加到购物车，您需要父变量产品 ID 和产品变体 ID（两者）。

现在您使用的代码已过时，如果客户在购物车页面更新购物车，删除所需的产品 ID，则该代码将不起作用。在这种情况下，礼品产品将在重新加载页面或跳转到另一个页面后被移除。所以template_redirect 不是正确的钩子。

尝试以下方法，也可以处理简单的产品和产品变体：

add_action( 'woocommerce_before_calculate_totals', 'wc_auto_add_gift_to_cart' );
function wc_auto_add_gift_to_cart( $cart ) {
    if (is_admin() && !defined('DOING_AJAX'))
        return;
    
    $required_product_id = 37; // The required product Id (or variation Id)
    $parent_gift_id      = 40; // The parent variable product Id (gift) for a product variation (set to zero for simple products)
    $product_gift_id     = 41; // the variation Id or the product Id (gift)
    
    $has_required = $gift_key = false; // Initializing
    
    foreach ( $cart->get_cart() as $cart_item_key => $cart_item ) {
        // Check if required product is in cart
        if( in_array( $required_product_id, array($cart_item['product_id'], $cart_item['variation_id']) ) ) {
           $has_required = true;
        }
        // Check if gifted product is already in cart
        if( $cart_item['data']->get_id() == $product_gift_id ) {
           $gift_key = $cart_item_key;
        }
    }
    
    // If gift is in cart, but not the required product: Remove gift from cart
    if ( ! $has_required && $gift_key ) {
        $cart->remove_cart_item( $gift_key );
    }
    // If gift is not in cart and the required product is in cart: Add gift to cart
    elseif ( $has_required && ! $gift_key ) {
        // For simple products
        if( $parent_gift_id == 0 ) {
            $cart->add_to_cart( $product_gift_id );
        } 
        // For product variations (of a variable product)
        else {
            $cart->add_to_cart( $parent_gift_id, 1, $product_gift_id );
        }
    }
}

代码在您的活动子主题（或活动主题）的functions.php 文件中。经过测试并且可以工作。