Php 在WooCommerce中以编程方式添加特定产品后，将价格设置为零

当您将产品添加到购物车时，方法add_to_cart()返回cart item key，下面我们将在woocommerce_before_calculate_totals挂钩中使用的WC_SESSION变量中设置购物车项目键，以检索正确的购物车项目以将其价格更改为零.

假设您的jQuery代码工作正常，并通过AJAX发送要添加的产品ID:

<script>
const selectedProductId = getProdVal(randomDegree);
const isProductInCart = isProductAlreadyInCart(selectedProductId);

if (!productAdded && !isProductInCart) {
    jQuery.ajax({
        url: <?php echo json_encode(admin_url('admin-ajax.php')) ?>,
        type: 'POST',
        data: {
            action: 'custom_add_to_cart', // <== Renamed
            product_id: selectedProductId,
        },
        success: function(response) {
            console.log(response);
            productAdded = true;
            spinBtn.disabled = false;
        },
        error: function(error) {
            console.error(error);
            spinBtn.disabled = false;
        }
    });
}
</script>

PHP:

add_action('wp_ajax_custom_add_to_cart', 'custom_add_to_cart');
add_action('wp_ajax_nopriv_custom_add_to_cart', 'custom_add_to_cart');
function custom_add_to_cart() {
    if (isset($_POST['product_id']) && $_POST['product_id'] > 0 ) {
        $product_id = intval($_POST['product_id']);

        if (!in_array($product_id, get_product_ids_from_cart())) {
            // Get previous added products (if any) from WC_Session variable
            $items_keys = (array) WC()->session->get('zero_price_items'); 
            
            $cart_item_key = WC()->cart->add_to_cart($product_id, 1); // Add product 
            $items_keys[$cart_item_key] = $product_id; // add the key to the array

            // Save cart item key in a WC_Session variable
            WC()->session->set('zero_price_items', $items_keys );

            echo json_encode(array('success' => true, 'message' => 'Product added to cart.'));
        } else {
            echo json_encode(array('success' => true, 'message' => 'Product already in cart.'));
        }
    } else {
        echo json_encode(array('success' => false, 'message' => 'Product ID is missing.'));
    }
    wp_die();
}

// Change cart item price
add_action('woocommerce_before_calculate_totals', 'custom_set_cart_item_price');
function custom_set_cart_item_price( $cart ) {
    if ( ( is_admin() && ! defined( 'DOING_AJAX' ) ) )
        return;

    if ( did_action( 'woocommerce_before_calculate_totals' ) >= 2 )
        return;

    $items_keys = (array) WC()->session->get('zero_price_items'); // Get the WC_Session variable data

    // Loop through cart items
    foreach ($cart->get_cart() as $cart_item_key => $cart_item) {
        // Check if the product has been added via custom ajax
        if ( isset($items_keys[$cart_item_key]) && $items_keys[$cart_item_key] == $cart_item['product_id'] ) {
            $cart_item['data']->set_price(0);
        }
    }
}

// For mini cart displayed price
add_action( 'woocommerce_cart_item_price', 'filter_cart_item_price', 10, 2 );
function filter_cart_item_price( $price_html, $cart_item, $cart_item_key ) {
    $items_keys = (array) WC()->session->get('zero_price_items'); // Get the WC_Session variable data

    // Check if the product has been added via custom ajax
    if ( isset($items_keys[$cart_item_key]) && $items_keys[$cart_item_key] == $cart_item['product_id'] ) {
        return wc_price( 0 );
    }
    return $price_html;
}

代码放在导览子主题的unctions.php文件中(或在插件中).应该能行得通.