How can Magento 2 restrict access to specified categories based on customer login status?

Magento 2 can restrict access to specific categories by leveraging observers and event handling. Here’s how you can achieve this:

1)Create an Observer:

Create a custom observer class that implements MagentoFrameworkEventObserverInterface. This observer will listen to the controller_action_predispatch_catalog_category_view event.

<?php
namespace VendorModuleObserver;


use MagentoFrameworkEventObserverInterface;
use MagentoFrameworkAppRequestInterface;
use MagentoFrameworkAppResponseRedirectInterface;
use MagentoCustomerModelSession as CustomerSession;


class RestrictCategoryAccess implements ObserverInterface
{
    protected $customerSession;
    protected $redirect;


    public function __construct(
        CustomerSession $customerSession,
        RedirectInterface $redirect
    ) {
        $this->customerSession = $customerSession;
        $this->redirect = $redirect;
    }


    public function execute(MagentoFrameworkEventObserver $observer)
    {
        if (!$this->customerSession->isLoggedIn()) {
            $categoryIdsToRestrict = [1, 2, 3]; // Replace with your category IDs


            $categoryId = (int) $observer->getEvent()->getRequest()->getParam('id');


            if (in_array($categoryId, $categoryIdsToRestrict)) {
                $this->redirect->redirect($observer->getEvent()->getResponse(), 'customer/account/login');
            }
        }
    }
}

2)Configure the Observer:

Declare your observer in the events.xml file of your module to listen to the controller_action_predispatch_catalog_category_view event.

<?xml version="1.0"?>
<config xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="urn:magento:framework:Event/etc/events.xsd">
    <event name="controller_action_predispatch_catalog_category_view">
        <observer name="restrict_category_access" instance="VendorModuleObserverRestrictCategoryAccess" />
    </event>
</config>