How to override order.php vendor/magento/module-sales/Model/Order.php in custom module magento 2?

Question

In Order.php i am trying to override getShippingMethod and getShippingDescription method but it is not loading the page and in logs

Order.php

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


use Magento\Sales\Api\Data\OrderInterface;
use Magento\Framework\App\ObjectManager;
class Order extends \Magento\Sales\Model\Order
{
    private $_objectManager;

   public function __construct(
        \Magento\Framework\Model\Context $context,
        \Magento\Framework\App\ObjectManager $objectManager
    ) {

      $this->_objectManager = $objectManager;
        parent::__construct(
            $context
        );
    }


    public function getShippingDescription()
    {
        $helper_factory = $this->_objectManager->get('Vendor\PickupAtStore\Helper\Data');
        ObjectManager::getInstance()->get(ResolverInterface::class)
        if($this->getShippingMethod() == "pickupatstore_pickupatstore_1"){
            //return $this->getData(OrderInterface::SHIPPING_DESCRIPTION);
            return "Shop – collect from 11am on your preferred day.(".$helper_factory->formatDatetime($order->getPickupDatetime()).")";
            }
            else
            {
                return $this->getData(OrderInterface::SHIPPING_DESCRIPTION);
        }

    }


   public function getShippingMethod($asObject = false)
    {
        $shippingMethod = parent::getShippingMethod();
        if (!$asObject) {
            return $shippingMethod;
        } else {
            list($carrierCode, $method) = explode('_', $shippingMethod, 2);
            return new \Magento\Framework\DataObject(['carrier_code' => $carrierCode, 'method' => $method]);
        }
    }
    /**
     * @return string
     */


    //@codeCoverageIgnoreEnd
}   

di.xml

<?xml version="1.0"?>
<config xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="urn:magento:framework:ObjectManager/etc/config.xsd">

    <preference for="Magento\Sales\Model\Order" type="Vendor\Module\Model\Order" />

</config>

Answer 1

app/code/VendoreName/ModuleName/etc

di.xml

<?xml version="1.0"?>

<config xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="urn:magento:framework:ObjectManager/etc/config.xsd">
    <preference for="Magento\Sales\Model\Order" type="VendoreName\ModuleName\Model\Order" />
</config>

app/code/VendoreName/ModuleName/Model

Order.php

<?php

namespace VendoreName\ModuleName\Model;

use Magento\Directory\Model\RegionFactory;
use Magento\Framework\Api\AttributeValueFactory;
use Magento\Framework\Api\SearchCriteriaBuilder;
use Magento\Framework\App\Config\ScopeConfigInterface;
use Magento\Framework\Locale\ResolverInterface;
use Magento\Framework\Pricing\PriceCurrencyInterface;
use Magento\Sales\Api\OrderItemRepositoryInterface;
use Magento\Sales\Model\Order\Payment;
use Magento\Sales\Model\Order\ProductOption;
use Magento\Sales\Model\ResourceModel\Order\Address\Collection;

class Order extends \Magento\Sales\Model\Order
{
    public function __construct(
        \Magento\Framework\Model\Context $context,
        \Magento\Framework\Registry $registry,
        \Magento\Framework\Api\ExtensionAttributesFactory $extensionFactory,
        AttributeValueFactory $customAttributeFactory,
        \Magento\Framework\Stdlib\DateTime\TimezoneInterface $timezone,
        \Magento\Store\Model\StoreManagerInterface $storeManager,
        \Magento\Sales\Model\Order\Config $orderConfig,
        \Magento\Catalog\Api\ProductRepositoryInterface $productRepository,
        \Magento\Sales\Model\ResourceModel\Order\Item\CollectionFactory $orderItemCollectionFactory,
        \Magento\Catalog\Model\Product\Visibility $productVisibility,
        \Magento\Sales\Api\InvoiceManagementInterface $invoiceManagement,
        \Magento\Directory\Model\CurrencyFactory $currencyFactory,
        \Magento\Eav\Model\Config $eavConfig,
        \Magento\Sales\Model\Order\Status\HistoryFactory $orderHistoryFactory,
        \Magento\Sales\Model\ResourceModel\Order\Address\CollectionFactory $addressCollectionFactory,
        \Magento\Sales\Model\ResourceModel\Order\Payment\CollectionFactory $paymentCollectionFactory,
        \Magento\Sales\Model\ResourceModel\Order\Status\History\CollectionFactory $historyCollectionFactory,
        \Magento\Sales\Model\ResourceModel\Order\Invoice\CollectionFactory $invoiceCollectionFactory,
        \Magento\Sales\Model\ResourceModel\Order\Shipment\CollectionFactory $shipmentCollectionFactory,
        \Magento\Sales\Model\ResourceModel\Order\Creditmemo\CollectionFactory $memoCollectionFactory,
        \Magento\Sales\Model\ResourceModel\Order\Shipment\Track\CollectionFactory $trackCollectionFactory,
        \Magento\Sales\Model\ResourceModel\Order\CollectionFactory $salesOrderCollectionFactory,
        PriceCurrencyInterface $priceCurrency,
        \Magento\Catalog\Model\ResourceModel\Product\CollectionFactory $productListFactory,
        \Magento\Framework\Model\ResourceModel\AbstractResource $resource = null,
        \Magento\Framework\Data\Collection\AbstractDb $resourceCollection = null,
        array $data = [],
        ResolverInterface $localeResolver = null,
        ProductOption $productOption = null,
        OrderItemRepositoryInterface $itemRepository = null,
        SearchCriteriaBuilder $searchCriteriaBuilder = null,
        ScopeConfigInterface $scopeConfig = null,
        RegionFactory $regionFactory = null
    ) {

        parent::__construct(
            $context,
            $registry,
            $extensionFactory,
            $customAttributeFactory,
            $timezone,
            $storeManager,
            $orderConfig,
            $productRepository,
            $orderItemCollectionFactory,
            $productVisibility,
            $invoiceManagement,
            $currencyFactory,
            $eavConfig,
            $orderHistoryFactory,
            $addressCollectionFactory,
            $paymentCollectionFactory,
            $historyCollectionFactory,
            $invoiceCollectionFactory,
            $shipmentCollectionFactory,
            $memoCollectionFactory,
            $trackCollectionFactory,
            $salesOrderCollectionFactory,
            $priceCurrency,
            $productListFactory,
            $resource,
            $resourceCollection,
            $data,
            $localeResolver,
            $productOption,
            $itemRepository,
            $searchCriteriaBuilder,
            $scopeConfig,
            $regionFactory
        );
    }

    public function customFunction()
    {
        echo "I am Custom Function";
        exit();
    }
}