我想停止特定客户群购买不超过两种产品，并停止magento2中特定数量的购物车

Question

我想阻止特定客户群购买不超过两种产品。我还需要阻止他们购物车中的特定数量。 如果是的话，这可能吗？那么执行该观察者、插件或偏好的最佳方法是什么？ 如果有人以前做过，请分享您的解决方案。

我尝试通过插件停止添加到购物车来完成此操作，但页面重新加载，我无法显示异常消息。

<?php
namespace CustomPlugin\CartProductRestriction\Plugin\Cart;

use Magento\Checkout\Controller\Cart\Add;
use Magento\Framework\Message\ManagerInterface;
use Magento\Checkout\Model\Cart;

class RestrictCartQty
{
    protected $customerSession;
    protected $messageManager;
    protected $cart;

    public function __construct(
        \Magento\Customer\Model\Session $customerSession,
        ManagerInterface $messageManager,
        Cart $cart
    ) {
        $this->customerSession = $customerSession;
        $this->messageManager = $messageManager;
        $this->cart = $cart;
    }

    public function aroundExecute(Add $subject, callable $proceed)
    {

        $allowedCustomerGroup = 4;
        $customerGroupId = $this->customerSession->getCustomer()->getGroupId();

        if ($customerGroupId == $allowedCustomerGroup) {


            $itemCount = $this->cart->getQuote()->getItemsQty();

            if ($itemCount >= 2) {
                $message = __('You can only add 2 items to your cart.');
                $this->messageManager->addError($message);
                return $subject;
            }
        }

        return $proceed();
    }
}

Answer 1

//di.xml file
<?xml version="1.0" encoding="utf-8"?>
<config xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="urn:magento:framework:ObjectManager/etc/config.xsd">
    <type name="Magento\Quote\Model\Quote">
        <plugin name="limit_cart_items_plugin_name" type="YourVendor\YourModule\Plugin\Quote\ClassName" sortOrder="10" disabled="false"/>
    </type>
</config>

//YourVendor\YourModule\Plugin\Quote
<?php
namespace YourVendor\YourModule\Plugin\Quote;

use Magento\Quote\Model\Quote;
use Magento\Framework\Exception\LocalizedException;

class ClassName
{
    public function beforeBeforeSave(Quote $subject)
    {
        $customerGroupId = $subject->getCustomerGroupId();

        // Define the customer group(s) you want to restrict
        $restrictedCustomerGroups = [1, 3];

        // Check if the customer group is in the restricted list
        if (in_array($customerGroupId, $restrictedCustomerGroups)) {
            // Get the items in the cart
            $items = $subject->getAllItems();

            // Define the maximum number of items allowed in the cart
            $maxItemsAllowed = 2;

            // Define the maximum cart total amount and here get specific amount
            $maxCartTotal = 120; 

            $totalQty = 0;
            $cartTotal = 0;
            $itemsToRemove = [];

            foreach ($items as $item) {
                $totalQty += $item->getQty();
                $cartTotal += $item->getRowTotal();

                // Check if the item quantity exceeds the limit
                if ($item->getQty() > $maxItemsAllowed) {
                    $itemsToRemove[] = $item;
                }
            }

            // Check if the cart exceeds the limits
            if ($totalQty > $maxItemsAllowed || $cartTotal > $maxCartTotal) {
                // Remove extra items
                foreach ($itemsToRemove as $itemToRemove) {
                    $subject->removeItem($itemToRemove->getId());
                }
                throw new LocalizedException(__('You can only add up to 2 products to your cart. and maximum amount 120.'));
            }
        }

        return [$subject]; 
    }
}