disable a cash on delivery payment method on the checkout for specific products

Question

I want to disable a cash on delivery payment method on the checkout for specific products I followed the code in this question

Disable Payment Method at Checkout in Magento 2 Based on Product Attribute

I modified the payment name in this file

Vendor/DisableCOD/Observer/DisablePaymentMethods.php

to cashondelivery

<?php
namespace Vendor\DisableCOD\Observer;
use Magento\Framework\Event\Observer;
use Magento\Framework\Event\ObserverInterface;
use Magento\Framework\App\Request\DataPersistorInterface;
use Magento\Framework\App\ObjectManager;
class DisablePaymentMethods implements ObserverInterface
{
    public function __construct(\Psr\Log\LoggerInterface $logger)
    {
        $this->_logger = $logger;
    }
    /**
     *
     * @param \Magento\Framework\Event\Observer $observer
     * @return void
     */
    public function execute(\Magento\Framework\Event\Observer $observer)
    {
        $objectManager = \Magento\Framework\App\ObjectManager::getInstance();
        $cart = $objectManager->get('\Magento\Checkout\Model\Cart'); 

        // get cart items
        $items = $cart->getItems();

        // get attribute value of cart items
        foreach ($items as $item) 
        {
            $p = $objectManager->get('Magento\Catalog\Model\Product')->load($item['product_id']);
            $attribute = $p->getResource()->getAttribute('cod'); 

            if ($attribute) 
            {
                $attr_value = $attribute ->getFrontend()->getValue($p);
                if($attr_value == 'Yes' || $attr_value == 'yes' || $attr_value == 'YES')
                {
                    if($observer->getEvent()->getMethodInstance()->getCode()=="cashondelivery")
                    {
                        $checkResult = $observer->getEvent()->getResult();
                        $checkResult->setData('is_available', false); 
                    }
                }

            }
        }
    }
}

then I created new Product Attribute that named 'cod' with input type 'Yes/No' but nothing happened the cash on delivery method still enabled for

Answer 1

The Catalog attribute Yes/No input type uses the Magento\Eav\Model\Entity\Attribute\Source\Boolean class as the source model and has int as the backend type.

The Magento\Eav\Model\Entity\Attribute\Source\Boolean class source model has a value of 1 for Yes and 0 for No.

<?php
/**
 * Copyright © Magento, Inc. All rights reserved.
 * See COPYING.txt for license details.
 */
namespace Magento\Eav\Model\Entity\Attribute\Source;

/**
 * @api
 * @since 100.0.2
 */
class Boolean extends \Magento\Eav\Model\Entity\Attribute\Source\AbstractSource
{
    /**
     * Option values
     */
    const VALUE_YES = 1;

    const VALUE_NO = 0;

...

    /**
     * Retrieve all options array
     *
     * @return array
     */
    public function getAllOptions()
    {
        if ($this->_options === null) {
            $this->_options = [
                ['label' => __('Yes'), 'value' => self::VALUE_YES],
                ['label' => __('No'), 'value' => self::VALUE_NO],
            ];
        }
        return $this->_options;
    }
    ...
}

Therefore, to check if the attribute value is Yes, you need to replace the following code:

if($attr_value == 'Yes' || $attr_value == 'yes' || $attr_value == 'YES')

with

if ($attr_value)

Additionally, to retrieve the product attribute value, you can use the $item variable without the need to load the product model:

$CODAttributeValue = $item->getProduct()->getData('cod');

To follow best practices, you shouldn't use the Object Manager in your code. There is a post discussing this To use or not to use the ObjectManager directly?

To optimize your code, you can replace your class with the following content:

<?php
declare(strict_types=1);

namespace Vendor\DisableCOD\Observer;

use Magento\Framework\DataObject;
use Magento\Framework\Event\Observer;
use Magento\Framework\Event\ObserverInterface;
use Magento\Framework\Exception\LocalizedException;
use Magento\OfflinePayments\Model\Cashondelivery;
use Magento\Payment\Model\Method\AbstractMethod;
use Magento\Quote\Api\Data\CartInterface;

class DisablePaymentMethods implements ObserverInterface
{
    /**
     * Disable Cash On Delivery payment method based on defined the `cod` product attribute
     *
     * @param Observer $observer
     * @throws LocalizedException
     */
    public function execute(Observer $observer)
    {
        /** @var DataObject $result */
        $result = $observer->getResult();
        /** @var AbstractMethod $methodInstance */
        $methodInstance = $observer->getMethodInstance();
        /** @var CartInterface $quote */
        $quote = $observer->getQuote();
        $paymentCode = $methodInstance->getCode();

        if ($paymentCode === Cashondelivery::PAYMENT_METHOD_CASHONDELIVERY_CODE) {
            $allItems = $quote->getAllItems();
            /** @var $item \Magento\Quote\Model\Quote\Item */
            foreach ($allItems as $item) {
                if ($item->getProduct()->getData('cod')) {
                    $result->setData('is_available', false);
                    break;
                }
            }
        }
    }
}