Magento 2 : Override Magento\SalesRule\Model\RulesApplier class

Question

How to override Magento\SalesRule\Model\RulesApplier class in custom module ?

i have tried

etc/di.xml

<preference for="Magento\SalesRule\Model\RulesApplier" type="Myvendor\SalesRule\Model\RulesApplier" />

Myvendor/SalesRule/Model/RulesApplier.php <?php

namespace Myvendor\SalesRule\Model;

use Magento\Quote\Model\Quote\Address;
use Magento\Quote\Model\Quote\Item\AbstractItem;
use Magento\SalesRule\Model\Quote\ChildrenValidationLocator;
use Magento\Framework\App\ObjectManager;
use Magento\SalesRule\Model\ResourceModel\Rule\Collection;
use Magento\SalesRule\Model\Rule\Action\Discount\CalculatorFactory;
use Magento\SalesRule\Model\Rule\Action\Discount\DataFactory;
use Magento\SalesRule\Api\Data\RuleDiscountInterfaceFactory;
use Magento\SalesRule\Api\Data\DiscountDataInterfaceFactory;
use Magento\GiftCard\Model\Catalog\Product\Type\Giftcard as GiftCardType;

/**
 * Rule applier model
 */
class RulesApplier extends \Magento\SalesRule\Model\RulesApplier
{
    /**
     * Application Event Dispatcher
     *
     * @var \Magento\Framework\Event\ManagerInterface
     */
    protected $_eventManager;

    /**
     * @var \Magento\SalesRule\Model\Utility
     */
    protected $validatorUtility;

    /**
     * @var ChildrenValidationLocator
     */
    private $childrenValidationLocator;

    /**
     * @var CalculatorFactory
     */
    private $calculatorFactory;

    /**
     * @var \Magento\SalesRule\Model\Rule\Action\Discount\DataFactory
     */
    protected $discountFactory;

    /**
     * @var RuleDiscountInterfaceFactory
     */
    private $discountInterfaceFactory;

    /**
     * @var DiscountDataInterfaceFactory
     */
    private $discountDataInterfaceFactory;

    /**
     * @var array
     */
    private $discountAggregator;

    /**
     * RulesApplier constructor.
     * @param CalculatorFactory $calculatorFactory
     * @param \Magento\Framework\Event\ManagerInterface $eventManager
     * @param Utility $utility
     * @param ChildrenValidationLocator|null $childrenValidationLocator
     * @param DataFactory|null $discountDataFactory
     * @param RuleDiscountInterfaceFactory|null $discountInterfaceFactory
     * @param DiscountDataInterfaceFactory|null $discountDataInterfaceFactory
     */
    public function __construct(
        \Magento\SalesRule\Model\Rule\Action\Discount\CalculatorFactory $calculatorFactory,
        \Magento\Framework\Event\ManagerInterface $eventManager,
        \Magento\SalesRule\Model\Utility $utility,
        ChildrenValidationLocator $childrenValidationLocator = null,
        DataFactory $discountDataFactory = null,
        RuleDiscountInterfaceFactory $discountInterfaceFactory = null,
        DiscountDataInterfaceFactory $discountDataInterfaceFactory = null
    ) {
        $this->calculatorFactory = $calculatorFactory;
        $this->validatorUtility = $utility;
        $this->_eventManager = $eventManager;
        $this->childrenValidationLocator = $childrenValidationLocator
             ?: ObjectManager::getInstance()->get(ChildrenValidationLocator::class);
        $this->discountFactory = $discountDataFactory ?: ObjectManager::getInstance()->get(DataFactory::class);
        $this->discountInterfaceFactory = $discountInterfaceFactory
            ?: ObjectManager::getInstance()->get(RuleDiscountInterfaceFactory::class);
        $this->discountDataInterfaceFactory = $discountDataInterfaceFactory
            ?: ObjectManager::getInstance()->get(DiscountDataInterfaceFactory::class);
    }

    /**
     * Apply rules to current order item
     * Applied fix to prevent cart rule apply to gc product
     * @param AbstractItem $item
     * @param Collection $rules
     * @param bool $skipValidation
     * @param mixed $couponCode
     * @return array
     * @SuppressWarnings(PHPMD.CyclomaticComplexity)
     */
    public function applyRules($item, $rules, $skipValidation, $couponCode)
    {
        $address = $item->getAddress();
        $appliedRuleIds = [];
        $this->discountAggregator = [];
        /* @var $rule Rule */
        foreach ($rules as $rule) {
            if (!$this->validatorUtility->canProcessRule($rule, $address)) {
                continue;
            }
            if (!$skipValidation && !$rule->getActions()->validate($item)) {
                if (!$this->childrenValidationLocator->isChildrenValidationRequired($item)) {
                    continue;
                }
                $childItems = $item->getChildren();
                $isContinue = true;
                if (!empty($childItems)) {
                    foreach ($childItems as $childItem) {
                        if ($rule->getActions()->validate($childItem)) {
                            $isContinue = false;
                        }
                    }
                }
                if ($isContinue) {
                    continue;
                }
            }
            $product = $item->getProductType();
            if ($product != GiftCardType::TYPE_GIFTCARD) {
                $this->applyRule($item, $rule, $address, $couponCode);
            }
            $appliedRuleIds[$rule->getRuleId()] = $rule->getRuleId();

            if ($rule->getStopRulesProcessing()) {
                break;
            }
        }

        return $appliedRuleIds;
    }
}

This works but then "ADD to Cart" not working. no logs no error.

Answer 1

You can use it by around plugin. Instead of override use plugin code.

Create di.xml to add plugin code :

app/code/VendorName/ModuleName/etc/di.xml

<?xml version="1.0"?>
<!--
/**
 * Copyright © Magento, Inc. All rights reserved.
 * See COPYING.txt for license details.
 */
-->
<config xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:noNamespaceSchemaLocation="urn:magento:framework:Module/etc/module.xsd">
    <type name="Magento\SalesRule\Model\RulesApplier">
        <plugin name="sales_apply_plugin"
            type="VendorName\ModuleName\Plugin\SalesRule\Model\RulesApplier"
            sortOrder="1"/>
    </type>
</config>

Create RulesApplier.php plugin file

app/code/VendorName/ModuleName/Plugin/SalesRule/Model/RulesApplier.php

<?php
/**
 * Copyright © Magento, Inc. All rights reserved.
 * See COPYING.txt for license details.
 */

namespace VendorName\ModuleName\Plugin\SalesRule\Model;

class RulesApplier
{
  
    public function aroundApplyRules(
        \Magento\SalesRule\Model\RulesApplier $subject,
        \Closure $proceed,
        $item,
        $rules,
        $skipValidation,
        $couponCode
    ) {
        // Add your logic
        $result = $proceed($item, $rules, $skipValidation, $couponCode);
        return $result;
    }
}

Clean cache and check it.