以编程方式将 Woocommerce 订阅开关添加到购物车

我正在寻找一种以编程方式将两个 Woocommerce 订阅变体之间的切换添加到购物车的方法。 我们正在构建一个无头 WP 网站，因此我不想使用链接来完成此操作，如中所述这个问题 https://stackoverflow.com/questions/48327381/switch-subscription-add-directly-to-cart

我尝试了以下简单的方法，但它不允许这样做，因为用户已经订阅了：

WC()->cart->add_to_cart( 1907, 1, 1908 );

我想模仿当用户转到升级/降级页面，选择新变体并按下“切换订阅”时发生的情况。通常这意味着用户被发送到购物车中的开关进行结账，我只想将其添加到购物车，因为我们有自己的结账。

主要问题是，Woocommerce 认为，当通过订阅转换表单以外的任何其他方式将订阅产品添加到购物车时，该订阅产品是不可购买的。该表单发送几个 GET 参数，这些参数通过一些额外的验证发送 WC，然后如果其他一切都有效，则允许将商品添加到购物车。

我的解决方案是用我自己的一些功能来模拟这种验证，这些功能大部分是从订阅插件中窃取的。

/**
 * Must be set to true before programmatically adding subscription switch to cart.
 *
 * @var  bool
 */
$kbhl_adding_switch_to_cart = false;

/**
 * Array filled with data about current subscription.
 * Should only be retrieved by kbhl_get_current_subscription_data().
 *
 * @var  array
 */
$kbhl_global_current_subscription_data = array();


/**
 * Cache whether a given product is purchasable or not to save running lots of queries for the same product in the same request
 *
 *      $is_purchasable_cache taken from plugins\woocommerce-subscriptions\includes\class-wcs-limiter.php
 *
 * @var  array
 */
$kbhl_purchasable_cache = array();

/**
 * $user_subscriptions_to_product taken from plugins\woocommerce-subscriptions\includes\class-wcs-limiter.php
 *
 * @var  array
 */
$kbhl_user_subscriptions_to_product = array();


/**
 * If a product is being marked as not purchasable because it is limited and the customer has a subscription,
 * but the current request is to switch the subscription, then mark it as purchasable.
 *
 *        Function is_purchasable_switch() taken from plugins\woocommerce-subscriptions\includes\class-wcs-limiter.php
 *
 * @param   bool $is_purchasable  Current purchasable status.
 * @param   obj  $product         Product being checked.
 *
 * @return  bool                  New purchasable status.
 */
function kbhl_is_purchasable_switch( $is_purchasable, $product ) {
    global $kbhl_purchasable_cache;

    $kbhl_current_subscription_data = kbhl_get_current_subscription_data();

    // Only process this filter if running custom add switch function.
    if ( ! empty( $kbhl_current_subscription_data['id'] ) ) {
        return $is_purchasable;
    }

    $product_key = wcs_get_canonical_product_id( $product );

    // Set an empty cache if one isn't set yet.
    if ( ! isset( $kbhl_purchasable_cache[ $product_key ] ) ) {
        $kbhl_purchasable_cache[ $product_key ] = array();
    }

    // Exit early if we've already determined this product's purchasability via switching.
    if ( isset( $kbhl_purchasable_cache[ $product_key ]['switch'] ) ) {
        return $kbhl_purchasable_cache[ $product_key ]['switch'];
    }

    // If the product is already purchasble, we don't need to determine it's purchasibility via switching/auto-switching.
    if ( true === $is_purchasable || ! is_user_logged_in() || ! wcs_is_product_switchable_type( $product ) || ! WC_Subscriptions_Product::is_subscription( $product->get_id() ) ) {
        $kbhl_purchasable_cache[ $product_key ]['switch'] = $is_purchasable;
        return $kbhl_purchasable_cache[ $product_key ]['switch'];
    }

    $user_id            = get_current_user_id();
    $product_limitation = wcs_get_product_limitation( $product );

    if ( 'no' == $product_limitation || ! wcs_user_has_subscription( $user_id, $product->get_id(), wcs_get_product_limitation( $product ) ) ) {
        $kbhl_purchasable_cache[ $product_key ]['switch'] = $is_purchasable;
        return $kbhl_purchasable_cache[ $product_key ]['switch'];
    }

    // Adding to cart.
    if ( array_key_exists( $kbhl_current_subscription_data['id'], kbhl_get_user_subscriptions_to_product( $product, $user_id, $product_limitation ) ) ) {
        $is_purchasable = true;
    }

    $kbhl_purchasable_cache[ $product_key ]['switch'] = $is_purchasable;
    return $kbhl_purchasable_cache[ $product_key ]['switch'];
}
add_filter( 'woocommerce_subscription_is_purchasable', 'kbhl_is_purchasable_switch', 13, 2 );



/**
 * Gets a list of the customer subscriptions to a product with a particular limited status.
 *
 *        Function get_user_subscriptions_to_product() taken from plugins\woocommerce-subscriptions\includes\class-wcs-limiter.php
 *
 * @param WC_Product|int $product      The product object or product ID.
 * @param int            $user_id      The user's ID.
 * @param string         $limit_status The limit status.
 *
 * @return WC_Subscription[] An array of a customer's subscriptions with a specific status and product.
 */
function kbhl_get_user_subscriptions_to_product( $product, $user_id, $limit_status ) {
    global $user_subscriptions_to_product;
    $product_id = is_object( $product ) ? $product->get_id() : $product;
    $cache_key  = "{$product_id}_{$user_id}_{$limit_status}";

    if ( ! isset( $user_subscriptions_to_product[ $cache_key ] ) ) {
        // Getting all the customers subscriptions and removing ones without the product is more performant than querying for subscriptions with the product.
        $subscriptions = wcs_get_subscriptions(
            array(
                'customer_id' => $user_id,
                'status'      => $limit_status,
            )
        );

        foreach ( $subscriptions as $subscription_id => $subscription ) {
            if ( ! $subscription->has_product( $product_id ) ) {
                unset( $subscriptions[ $subscription_id ] );
            }
        }

        $user_subscriptions_to_product[ $cache_key ] = $subscriptions;
    }

    return $user_subscriptions_to_product[ $cache_key ];
}





/**
 * When a subscription switch is added to the cart, store a record of pertinent meta about the switch.
 *
 * @since 1.4
 */

/**
 * When a subscription switch is added to the cart, store a record of pertinent meta about the switch.
 *
 *       Function set_switch_details_in_cart() taken from plugins\woocommerce-subscriptions\includes\class-wc-subscriptions-switcher.php
 *
 * @param   array $cart_item_data    Current cart item data.
 * @param   int   $product_id        ID of current product.
 * @param   int   $variation_id      ID of current product variation.
 *
 * @return  array                   Updated cart item data.
 */
function kbhl_set_switch_details_in_cart( $cart_item_data, $product_id, $variation_id ) {
    try {

        $kbhl_current_subscription_data = kbhl_get_current_subscription_data();
        if ( empty( $kbhl_current_subscription_data['id'] ) || empty( $kbhl_current_subscription_data['item'] ) ) {
            return $cart_item_data;
        }

        $subscription = wcs_get_subscription( $kbhl_current_subscription_data['id'] );

        // Requesting a switch for someone elses subscription.
        if ( ! current_user_can( 'switch_shop_subscription', $subscription->get_id() ) ) {
            wc_add_notice( __( 'You can not switch this subscription. It appears you do not own the subscription.', 'woocommerce-subscriptions' ), 'error' );
            WC()->cart->empty_cart( true );
            return array();
        }

        $item = wcs_get_order_item( absint( $kbhl_current_subscription_data['item'] ), $subscription );

        // Else it's a valid switch.
        $product         = wc_get_product( $item['product_id'] );
        $parent_products = WC_Subscriptions_Product::get_parent_ids( $product );
        $child_products  = array();

        if ( ! empty( $parent_products ) ) {
            foreach ( $parent_products as $parent_id ) {
                $child_products = array_unique( array_merge( $child_products, wc_get_product( $parent_id )->get_children() ) );
            }
        }

        if ( $product_id != $item['product_id'] && ! in_array( $item['product_id'], $child_products ) ) {
            return $cart_item_data;
        }

        $next_payment_timestamp = $subscription->get_time( 'next_payment' );

        // If there are no more payments due on the subscription, because we're in the last billing period, we need to use the subscription's expiration date, not next payment date.
        if ( false == $next_payment_timestamp ) {
            $next_payment_timestamp = $subscription->get_time( 'end' );
        }

        $cart_item_data['subscription_switch'] = array(
            'subscription_id'        => $subscription->get_id(),
            'item_id'                => absint( $kbhl_current_subscription_data['item'] ),
            'next_payment_timestamp' => $next_payment_timestamp,
            'upgraded_or_downgraded' => '',
        );

        return $cart_item_data;

    } catch ( Exception $e ) {

        wc_add_notice( __( 'There was an error locating the switch details.', 'woocommerce-subscriptions' ), 'error' );
        WC()->cart->empty_cart( true );
        return array();
    }
}
add_filter( 'woocommerce_add_cart_item_data', 'kbhl_set_switch_details_in_cart', 11, 3 );





/**
 * Gets subscription data for current user.
 *
 * @return  array  Subscription data, also stored to global variable $kbhl_global_current_subscription_data
 */
function kbhl_get_current_subscription_data() {
    global $kbhl_adding_switch_to_cart, $kbhl_global_current_subscription_data;

    if ( ! $kbhl_adding_switch_to_cart ) {
        return array();
    }

    if ( ! empty( $kbhl_global_current_subscription_data ) ) {
        return $kbhl_global_current_subscription_data;
    }

    $subscription_data = array();
    $subs              = wcs_get_users_subscriptions();

    if ( ! empty( $subs ) ) {
        foreach ( $subs as $sub ) {
            $subscription_data['id'] = $sub->get_id();

            foreach ( $sub->get_items() as $item_id => $item ) {
                $subscription_data['item'] = $item_id;
                break; // There should only be 1 order item.
            }

            break; // There should only be 1 subscription.
        }
    }

    $kbhl_global_current_subscription_data = $subscription_data;

    return $kbhl_global_current_subscription_data;
}

添加后，您可以将交换机添加到购物车，如下所示：

global $kbhl_adding_switch_to_cart; // If run inside a function.
WC()->cart->empty_cart( true );
$kbhl_adding_switch_to_cart = true;
WC()->cart->add_to_cart( 1907, 1, 1927 );
$kbhl_adding_switch_to_cart = false; // Reset after to get back to default validation.