Magento2 rewrite: product resource collection class does not effect on functions

Question

I have rewrite catalog product resource collection Magento\Catalog\Model\ResourceModel\Product\Collection.

Class override successfully but functions override is not working.

Suppose, i want overrider setOrder()function. But it does not works . Always calling Core function instead of rewrite class function

Class

<?php
namespace AmitBera\CoreRewrite\Model\Rewrite\Catalog\ResourceModel\Product;

class Collection extends \Magento\Catalog\Model\ResourceModel\Product\Collection
{

    protected $appState;
    public function __construct(
        \Magento\Framework\Data\Collection\EntityFactory $entityFactory,
        \Psr\Log\LoggerInterface $logger,
        \Magento\Framework\Data\Collection\Db\FetchStrategyInterface $fetchStrategy,
        \Magento\Framework\Event\ManagerInterface $eventManager,
        \Magento\Eav\Model\Config $eavConfig,
        \Magento\Framework\App\ResourceConnection $resource,
        \Magento\Eav\Model\EntityFactory $eavEntityFactory,
        \Magento\Catalog\Model\ResourceModel\Helper $resourceHelper,
        \Magento\Framework\Validator\UniversalFactory $universalFactory,
        \Magento\Store\Model\StoreManagerInterface $storeManager,
        \Magento\Framework\Module\Manager $moduleManager,
        \Magento\Catalog\Model\Indexer\Product\Flat\State $catalogProductFlatState,
        \Magento\Framework\App\Config\ScopeConfigInterface $scopeConfig,
        \Magento\Catalog\Model\Product\OptionFactory $productOptionFactory,
        \Magento\Catalog\Model\ResourceModel\Url $catalogUrl,
        \Magento\Framework\Stdlib\DateTime\TimezoneInterface $localeDate,
        \Magento\Customer\Model\Session $customerSession,
        \Magento\Framework\Stdlib\DateTime $dateTime,
        \Magento\Framework\App\State $appState,
        \Magento\Customer\Api\GroupManagementInterface $groupManagement,
        \Magento\Framework\DB\Adapter\AdapterInterface $connection = null
    ) {
        parent::__construct(
                $entityFactory,
                $logger,
                $fetchStrategy,
                $eventManager,
                $eavConfig,
                $resource,
                $eavEntityFactory,
                $resourceHelper,
                $universalFactory,
                $storeManager,
                $moduleManager,
                $catalogProductFlatState,
                $scopeConfig,
                $productOptionFactory,
                $catalogUrl,
                $localeDate,
                $customerSession,
                $dateTime,
                $groupManagement,
                        $connection
            );
        $this->_appState = $appState;

    }
   public function setOrder($attribute, $dir = \Magento\Framework\DB\Select::SQL_DESC)
    {
        echo __METHOD__;
        exit;
        if ($attribute == 'price') {
            $this->addAttributeToSort($attribute, $dir);
        } else {
            parent::setOrder($attribute, $dir);
        }
        return $this;
    }


}

module.xml

<?xml version="1.0"?>
<config xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNameSpaceSchemaLocation="urn:magento:framework:Module/etc/module.xsd">
    <module name="AmitBera_CoreRewrite" setup_version="2.0.0">
        <sequence>
            <module name="Magento_Catalog"/> 
            <module name="Magento_CatalogSearch"/>         
            <module name="Magento_Checkout"/>
            <module name="Magento_Sales"/>
            <module name="Magento_Quote"/>
            <module name="Magento_Vault"/>
            <module name="Magento_OfflineShipping"/>           
        </sequence>     
    </module>
</config>

di.xml

<?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">
       <preference for="Magento\Catalog\Model\ResourceModel\Product\Collection" 
        type="AmitBera\CoreRewrite\Model\Rewrite\Catalog\ResourceModel\Product\Collection" />
</config>   

Whenever use

$objectManager = \Magento\Framework\App\ObjectManager::getInstance();
/** @var \Magento\Catalog\Model\ResourceModel\Product\Collection $productCollection */
$productCollection = $objectManager->create('Magento\Catalog\Model\ResourceModel\Product\Collection');
echo get_class($productCollection );

result:

AmitBera\CoreRewrite\Model\Rewrite\Catalog\ResourceModel\Product\Collection\Interceptor

Question:

• i donot understand why i am not able to override function setorder()
• Why echo get_class($productCollection ); give Interceptor class

AmitBera\CoreRewrite\Model\Rewrite\Catalog\ResourceModel\Product\Collection\Interceptor

Answer 1

If you overwriting Magento\Catalog\Model\ResourceModel\Product\Collection, just traverse this folder location, you will find the file and folder with same name i.e Collection. So its points to folder location collection.

If you want to do some function with sorting overwrite Magento\Catalog\Model\ResourceModel\Product\Collection\ProductLimitation or using plugin concept to set $productLimitationFilters