Add observer to add customer to guest order by matching email (Fixes #19)

Observer/SalesOrderPlaceAfterObserver.php

@@ -0,0 +1,69 @@
+<?php
+/**
+ * Copyright © MagePal LLC. All rights reserved.
+ * See COPYING.txt for license details.
+ * https://www.magepal.com | support@magepal.com
+ */
+
+namespace MagePal\GuestToCustomer\Observer;
+
+use Exception;
+use Magento\Customer\Api\CustomerRepositoryInterface;
+use Magento\Framework\Event\Observer as EventObserver;
+use Magento\Framework\Event\ObserverInterface;
+use MagePal\GuestToCustomer\Helper\Data;
+
+/**
+ * Class SalesOrderPlaceAfterObserver
+ * @package MagePal\GuestToCustomer\Observer
+ */
+class SalesOrderPlaceAfterObserver implements ObserverInterface
+{
+    /**
+     * @var CustomerRepositoryInterface
+     */
+    protected $customerRepository;
+
+    /**
+     * @var Data
+     */
+    protected $helperData;
+
+    /**
+     * @param Data $helperData
+     */
+    public function __construct(
+        CustomerRepositoryInterface $customerRepository,
+        Data $helperData
+    ) {
+        $this->customerRepository = $customerRepository;
+        $this->helperData = $helperData;
+    }
+
+    /**
+     * @param EventObserver $observer
+     * @throws Exception
+     */
+    public function execute(EventObserver $observer)
+    {
+        if (!$this->helperData->isMergeIfCustomerAlreadyExists()) {
+            return;
+        }
+
+        $order = $observer->getEvent()->getOrder();
+        if ($order->getCustomerId()) {
+            return;
+        }
+
+        try {
+            $customer = $this->customerRepository->get($order->getCustomerEmail(), $order->getStore()->getWebsiteId());
+            if (!$customer->getId()) {
+                return;
+            }
+            $order->setCustomerId($customer->getId());
+            $order->save();
+        } catch (Exception $e) {
+            //do nothing
+        }
+    }
+}

etc/events.xml

@@ -10,4 +10,8 @@
         <observer name="magepal_guest_to_customer_save_downloadable_product"
                   instance="MagePal\GuestToCustomer\Observer\UpdateDownloadableProductObserver" />
     </event>
+    <event name="sales_order_place_after">
+        <observer name="magepal_guest_to_customer_sales_order_place_after"
+                  instance="MagePal\GuestToCustomer\Observer\SalesOrderPlaceAfterObserver" />
+    </event>
 </config>