添加产品时，WooCommerce 将追加销售产品添加到购物车

我正在尝试在我的 WooCommerce 主题中实现自定义追加销售功能。 当用户添加产品时，我需要将额外的产品（追加销售）添加到其购物车。这意味着我必须向产品添加一个额外的参数，该参数允许我获取产品/追加销售的关系，并在从购物车中删除产品时删除关联的追加销售。

用户可以通过复选框列表选择这些追加销售产品。以下是我的“content-single-product.php”WooCommerce 模板的概述：

<form action="<?php echo esc_url( $product->add_to_cart_url() ); ?>" class="cart" method="post" enctype="multipart/form-data">
    <?php

    // Get Upsells Product ID:
    $upsells = $product->get_upsells();

    if ( sizeof( $upsells ) == 0 ) return;

    $meta_query = $woocommerce->query->get_meta_query();

    // Get Upsells:
    $args = array(
        'post_type'           => 'product',
        'ignore_sticky_posts' => 1,
        'no_found_rows'       => 1,
        'posts_per_page'      => $posts_per_page,
        'orderby'             => $orderby,
        'post__in'            => $upsells,
        'post__not_in'        => array( $product->id )
    );

    $query = new WP_Query( $args );

    if ( $query->have_posts() ): ?>
        <ul>
        <?php while ( $query->have_posts() ): $query->the_post(); ?>
            <label for="upsell_<?php the_ID(); ?>"><input type="checkbox" name="upsells[]" id="upsell_<?php the_ID(); ?>" value="<?php the_ID(); ?>" /> <?php the_title(); ?></label>
        <?php endwhile; ?>
        </ul>
    <?php endif; ?>

    <?php wp_reset_postdata(); ?>

    <button type="submit">Add to cart</button>
</form>

上面的代码已经简化了..

然后，这是我添加到functions.php中的代码，它允许我向购物车添加追加销售并向相关产品添加额外的行：

/**
 * Add upsells as extra data for added product
 */
function add_upsells_to_cart( $cart_item_key ) {
    global $woocommerce;

    if ( empty( $_REQUEST['upsells'] ) || ! is_array( $_REQUEST['upsells'] ) )
        return;

    // Prevent loop
    $upsells = $_REQUEST['upsells'];
    unset( $_REQUEST['upsells'] );

    // Add upsell_parent row (if not already existing) for the associated product
    if ( ! $cart_item_data['upsells'] || ! is_array( $cart_item_data['upsells'] ) )
        $cart_item_data['upsells'] = array();

    // Append each upsells to product in cart
    foreach( $upsells as $upsell_id ) {
        $upsell_id = absint( $upsell_id );

        // Add extra parameter to the product which contain the upsells
        $woocommerce->cart->cart_contents[ $cart_item_key ]['upsells'] = $upsell_id;

        // Add upsell to cart
        $woocommerce->cart->add_to_cart( $upsell_id );
    }
}
add_action( 'woocommerce_add_to_cart', 'add_upsells_to_cart' );

追加销售按预期添加到购物车，但额外的行似乎被 WC 中的某些内容删除了。

当我做一个print_r( $woocommerce->cart->cart_contents[ $cart_item_key ] );在上一个函数的末尾，额外的 upsells 参数是可见的，但是当我从购物车页面显示购物车时，upsells 参数将从购物车中删除。

任何想法？

谢谢， E.

所以最后，我找到了我的问题的解决方案。

当通过函数从会话加载购物车时出现问题get_cart_from_session() from class-wc-cart.php.

当额外的密钥添加到购物车项目时，我们需要通过以下方式注入密钥woocommerce_get_cart_item_from_session filter.

用户现在可以选择追加销售，该追加销售会在添加产品的同时自动添加到购物车。我还有一个功能，如果主要产品被删除，我可以删除追加销售。

这是我添加到functions.php中的最终代码：

/**
 * Add upsells as extra data for added product
 */
function add_upsells_to_cart( $cart_item_key ) {
    global $woocommerce;

    if ( empty( $_REQUEST['upsells'] ) || ! is_array( $_REQUEST['upsells'] ) )
        return;

    // Prevent loop
    $upsells = $_REQUEST['upsells'];
    unset( $_REQUEST['upsells'] );

    // Append each upsells to product in cart
    foreach( $upsells as $upsell_id ) {
        $upsell_id = absint( $upsell_id );

        // Add upsell into cart and set upsell_of as extra key with parent product item id
        $woocommerce->cart->add_to_cart( $upsell_id, 1, '', '', array( 'upsell_of' => $cart_item_key ) );
    }
}
add_action( 'woocommerce_add_to_cart', 'add_upsells_to_cart', 1, 6 );


/**
 * Inject upsell_of extra key cart item key when cart is loaded from session
 */
function get_cart_items_from_session( $item, $values, $key ) {
    if ( array_key_exists( 'upsell_of', $values ) )
        $item[ 'upsell_of' ] = $values['upsell_of'];

    return $item;
}
add_filter( 'woocommerce_get_cart_item_from_session', 'get_cart_items_from_session', 1, 3 );


/**
 * Remove associated upsells if product removed from cart
 */
function remove_upsells_from_cart( $cart_item_key ) {
    global $woocommerce;

    // Get cart
    $cart = $woocommerce->cart->get_cart();

    // For each item in cart, if item is upsell of deleted product, delete it
    foreach( $cart as $upsell_key => $upsell )
        if ( $upsell['upsell_of'] == $cart_item_key )
            unset( $woocommerce->cart->cart_contents[ $upsell_key ] );
}
add_action( 'woocommerce_before_cart_item_quantity_zero', 'remove_upsells_from_cart' );