如果购物车包含特定类别，则阻止添加到购物车 (WooCommerce)

Question

我有一个包含 5 个类别的商店。它是多供应商的，由于运输的复杂性，当购物车中只有一个特定类别（“油漆”）的产品时，我只能销售它们。因此，当购物车包含油漆时，我需要防止将任何非油漆产品添加到购物车，并显示错误消息，并且我需要防止将油漆产品添加到包含任何其他类别的购物车，并显示错误消息。

我尝试从 Stackoverflow 和其他地方找到的代码片段中拼凑出这段代码。这个逻辑似乎在我的大脑中起作用，但是当我尝试实现代码（通过functions.php）时，它会阻止任何产品添加到购物车，除非购物车是空的。

这是我的代码：

//*** Prevent mixture of paint and other prods in same cart ***//
function dont_add_paint_to_cart_containing_other() {

// Set flag false until we find a product in cat paint
$cat_check = false;

// Set $cat_check true if a cart item is in paint cat
foreach ( WC()->cart->get_cart() as $cart_item_key => $cart_item ) {

    $product = $cart_item['data'];

    if ( has_term( 'paint', 'product_cat', $product->id ) ) {
                $cat_check = true;
        // break because we only need one "true" to matter here
        break;
        }
}
// Return true if cart empty
if ( WC()->cart->get_cart_contents_count() == 0 ) {
    return true;
    }
    // If cart contains paint and product to be added is not paint, display error message and return false.
    elseif ( $cat_check && get_queried_object()->term_id != '245778522') {
        wc_add_notice( 'Sorry, you can only purchase paint products on their own. To purchase this product, please checkout your current cart or empty your cart and try again' , 'error' );
        return false;
    }
    // If cart contains a product that is not paint and product to be added is paint, display error message and return false.
    elseif (!$cat_check && get_queried_object()->term_id = '245778522') {
        wc_add_notice( 'Sorry, you can only purchase paint products on their own. To purchase this product, please checkout your current cart or empty your cart and try again' , 'error' );
        return false;
    }
    // Otherwise, return true.
    return true;
}

add_filter( 'woocommerce_add_to_cart_validation', 'dont_add_paint_to_cart_containing_other' );

Answer 1

//*** Prevent mixture of paint and other prods in same cart ***//
function dont_add_paint_to_cart_containing_other($validation, $product_id) {

// Set flag false until we find a product in cat paint
    $cart_has_paint = false;

// Set $cat_check true if a cart item is in paint cat
    foreach (WC()->cart->get_cart() as $cart_item_key => $cart_item) {

        $product = $cart_item['data'];

        if (has_term('paint', 'product_cat', $product->id)) {
            $cart_has_paint = true;
            // break because we only need one "true" to matter here
            break;
        }
    }

    $product_is_paint = false;
    if (has_term('paint', 'product_cat', $product_id)) {
        $product_is_paint = true;
    }

// Return true if cart empty
    if (!WC()->cart->get_cart_contents_count() == 0) {
        // If cart contains paint and product to be added is not paint, display error message and return false.
        if ($cart_has_paint && !$product_is_paint) {
            wc_add_notice('Sorry, you can only purchase paint products on their own. To purchase this product, please checkout your current cart or empty your cart and try again', 'error');
            $validation = false;
        }
        // If cart contains a product that is not paint and product to be added is paint, display error message and return false.
        elseif (!$cart_has_paint && $product_is_paint) {
            wc_add_notice('Sorry, you can only purchase paint products on their own. To purchase this product, please checkout your current cart or empty your cart and try again', 'error');
            $validation = false;
        }
    }
    // Otherwise, return true.
    return $validation;
}

add_filter('woocommerce_add_to_cart_validation', 'dont_add_paint_to_cart_containing_other', 10, 2);

改成这样