Setting Cart Quantity Limit in Magento 2: A Comprehensive Guide

One of the critical features an eCommerce store might require is the ability to set a limit on the quantity of items that can be added to the shopping cart. This feature is particularly useful for managing inventory and guiding customers to make balanced purchases. In this article, we will explore two methods to achieve this functionality in Magento 2:

Method 1: Using a Custom Module

Step 1: Create a Custom Module

You can develop a custom module to enforce a cart quantity limit. The following steps outline how to create and configure a custom module in Magento 2:

Create a directory for your module: app/code/Vendor/CartLimit

Create the necessary files for your module:

etc/module.xml etc/frontend/di.xml Observer folder (for custom logic)

File Structure

The file structure should look like this:

app/code/Vendor/CartLimit/
└── etc/
    ├── module.xml
    └── frontend/
        └── di.xml

Module Configuration (module.xml)

This file defines the module and its dependencies:

?xml version1.0?
config xmlns:xsi xsi:noNamespaceSchemaLocationurn:magento:framework:Module/etc/module.xsd
    module nameVendor_CartLimit setup_version1.0.0/
/config

Dependency Injection (di.xml)

This file is used for dependency injection:

config xmlns:xsi xsi:noNamespaceSchemaLocationurn:magento:framework:ObjectManager/etc/config.xsd
    type nameMagentoCheckoutModelCart
        plugins
            plugin nameVendor_CartLimit_Observer typeVendorCartLimitObserverCartLimitObserver/
        /plugins
    /type
/config

Observer Logic

Create an observer to handle the cart quantity limit:

?php namespace VendorCartLimitObserver/code
use MagentoFrameworkEventObserver;
use MagentoFrameworkEventObserverInterface;
class CartLimitObserver implements ObserverInterface/code
{
    const MAX_CART_ITEMS  10; // Set your limit here
    public function execute(Observer $observer)/code
    {
        $cart  $observer->getEvent()->getQuote();
        if ($cart->getItemsCount()  self::MAX_CART_ITEMS) {
            throw new MagentoFrameworkExceptionLocalizedException(__('You cannot add more than %1 items to the cart.', self::MAX_CART_ITEMS));
        }
    }
}

Step 2: Enable the Module

Once the module is created, you need to enable and deploy it:

Run the following Magento commands:

php bin/magento module:enable Vendor_CartLimit
php bin/magento setup:upgrade
php bin/magento cache:clean
php bin/magento cache:flush

Method 2: Using a Third-Party Extension

If you prefer not to write custom code, you can find third-party extensions available on the Magento Marketplace that offer this functionality. Simply search for cart quantity limit to find suitable extensions.

Conclusion

By following the steps above, you can effectively limit the quantity of items that can be added to the shopping cart in Magento 2. As with any custom development, it is essential to thoroughly test your changes in a development environment before deploying them to production.