Override abstract class

Question

I have to override Sender.php which path is Magento\Sales\Model\Order\Email

I try but its not work my code is :

di.xml

<type name="Magento\Sales\Model\Order\Email\Sender">
        <plugin name="module_name::aroundPrepareTemplate" type="module\name\Model\Order\Email\Sender" sortOrder="99999"/>
    </type>

module\name\Model\Order\Email Sender.php

<?php  

    namespace module\name\Model\Order\Email;

    use Magento\Sales\Model\Order;
    use Magento\Sales\Model\Order\Email\Container\IdentityInterface;
    use Magento\Sales\Model\Order\Email\Container\Template;
    use Magento\Sales\Model\Order\Address\Renderer;


    abstract class Sender
    {

        protected $senderBuilderFactory;


        protected $templateContainer;


        protected $identityContainer;

        protected $logger;


        protected $addressRenderer;


        public function __construct(
        Template $templateContainer,
        IdentityInterface $identityContainer,
        \Magento\Sales\Model\Order\Email\SenderBuilderFactory $senderBuilderFactory,
        \Psr\Log\LoggerInterface $logger,
        Renderer $addressRenderer
        ) {
            $this->templateContainer = $templateContainer;
            $this->identityContainer = $identityContainer;
            $this->senderBuilderFactory = $senderBuilderFactory;
            $this->logger = $logger;
            $this->addressRenderer = $addressRenderer;
        }


        public function aroundPrepareTemplate($subject,Order $order)
        {
            $this->templateContainer->setTemplateOptions($this->getTemplateOptions());
            $objectManager = \Magento\Framework\App\ObjectManager::getInstance();
            $orderItems = $order->getAllItems();

            foreach ($orderItems as $item) {

                $product = $objectManager->get('Magento\Catalog\Model\Product')->load($item->getProductId());
                $categoryIds = $product->getCategoryIds();

            }
            foreach($categoryIds as $catid){
                $_objectManager = \Magento\Framework\App\ObjectManager::getInstance();
                $category = $_objectManager->create('Magento\Catalog\Model\Category')
                ->load($catid);
            }


            if ($order->getCustomerIsGuest()) {
                $templateId = $this->identityContainer->getGuestTemplateId();
                $customerName = $order->getBillingAddress()->getName();
                } else {
                $templateId = $this->identityContainer->getTemplateId();
                $customerName = $order->getCustomerName();
            }

            if($catid == 461){ 
                $templateId = 11 ; 
            }


            $this->identityContainer->setCustomerName($customerName);
            $this->identityContainer->setCustomerEmail($order->getCustomerEmail());
            $this->templateContainer->setTemplateId($templateId);
        }


    }

Answer 1

For your requirement, I am suggesting not use Plugin and it little complicated at this method and

Plugin doesn't work on PrepareTemplate as this Method is protected

Suggesting to use Class rewrite using <preference></preference>.

di.xml code

<?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\Email\Sender\OrderSender" type="StackExchange\Magento\Rewrite\OrderSender" />
</config>

Rewrite class StackExchange\Magento\Rewrite\OrderSender.php

And code is below:

<?php
namespace StackExchange\Magento\Rewrite;

use Magento\Sales\Model\Order;
use Magento\Framework\DataObject;

class OrderSender extends \Magento\Sales\Model\Order\Email\Sender\OrderSender{

    /**
     * @var \Magento\Catalog\Api\ProductRepositoryInterface
     */
    private $productRepository;

    public function __construct(
            \Magento\Sales\Model\Order\Email\Container\Template $templateContainer, 
            \Magento\Sales\Model\Order\Email\Container\OrderIdentity $identityContainer, 
            \Magento\Sales\Model\Order\Email\SenderBuilderFactory $senderBuilderFactory,
            \Psr\Log\LoggerInterface $logger,
            \Magento\Sales\Model\Order\Address\Renderer $addressRenderer,
            \Magento\Payment\Helper\Data $paymentHelper,
            \Magento\Sales\Model\ResourceModel\Order $orderResource,
            \Magento\Framework\App\Config\ScopeConfigInterface $globalConfig,
            \Magento\Framework\Event\ManagerInterface $eventManager,
            \Magento\Catalog\Api\ProductRepositoryInterface $productRepository
     ) {
        parent::__construct($templateContainer, 
                $identityContainer,
                $senderBuilderFactory,
                $logger,
                $addressRenderer,
                $paymentHelper,
                $orderResource,
                $globalConfig,
                $eventManager
                );
                $this->productRepository = $productRepository;
    }
    protected function prepareTemplate(Order $order){

        $transport = [
            'order' => $order,
            'billing' => $order->getBillingAddress(),
            'payment_html' => $this->getPaymentHtml($order),
            'store' => $order->getStore(),
            'formattedShippingAddress' => $this->getFormattedShippingAddress($order),
            'formattedBillingAddress' => $this->getFormattedBillingAddress($order),
        ];
        $transportObject = new DataObject($transport);


        $this->eventManager->dispatch(
            'email_order_set_template_vars_before',
            ['sender' => $this, 'transport' => $transportObject, 'transportObject' => $transportObject]
        );

        $this->templateContainer->setTemplateVars($transportObject->getData());

        $this->templateContainer->setTemplateOptions($this->getTemplateOptions());

        if ($order->getCustomerIsGuest()) {
            $templateId = $this->identityContainer->getGuestTemplateId();
            $customerName = $order->getBillingAddress()->getName();
        } else {
            $templateId = $this->identityContainer->getTemplateId();
            $customerName = $order->getCustomerName();
        }
        $changeTemplateFlag = $this->changeOriginalTemplate($order);
        if($changeTemplateFlag){
            $templateId = 15;
        }
        $this->identityContainer->setCustomerName($customerName);
        $this->identityContainer->setCustomerEmail($order->getCustomerEmail());
        $this->templateContainer->setTemplateId($templateId);;
    }
    private function changeOriginalTemplate($order)
    {
        $this->logger->info(__METHOD__);
        $ConditionCategoryId = 4;
        $orderItems = $order->getAllItems();
        $categoryIds= [];
        foreach ($orderItems as $item) {
            try{
               $product = $this->productRepository
                       ->getById($item->getProductId(), false, $order->getStoreId());
            } catch (\Magento\Framework\Exception\NoSuchEntityException $ex) {
                  continue;  
            }
            $categoryIds = array_merge($categoryIds,$product->getCategoryIds());
        }
        $uniqueCategoryIds = array_unique($categoryIds);

        if(in_array($ConditionCategoryId, $categoryIds)){
            return true;
        }
        return false;

    }
}