PWA-806: Localize emails sent through GraphQL application

- Emulate correct store around email sends through GraphQL

Author: davemacaulay

app/code/Magento/StoreGraphQl/Controller/HttpHeaderProcessor/StoreProcessor.php

@@ -7,10 +7,6 @@
 
 namespace Magento\StoreGraphQl\Controller\HttpHeaderProcessor;
 
-use Magento\Framework\App\AreaInterface;
-use Magento\Framework\App\AreaList;
-use Magento\Framework\App\ObjectManager;
-use Magento\Framework\App\State;
 use Magento\GraphQl\Controller\HttpHeaderProcessorInterface;
 use Magento\Store\Model\StoreManagerInterface;
 use Magento\Framework\App\Http\Context as HttpContext;
@@ -36,35 +32,19 @@ class StoreProcessor implements HttpHeaderProcessorInterface
      */
     private $storeCookieManager;
 
-    /**
-     * @var AreaList
-     */
-    private $areaList;
-
-    /**
-     * @var State
-     */
-    private $appState;
-
     /**
      * @param StoreManagerInterface $storeManager
      * @param HttpContext $httpContext
      * @param StoreCookieManagerInterface $storeCookieManager
-     * @param AreaList $areaList
-     * @param State $appState
      */
     public function __construct(
         StoreManagerInterface $storeManager,
         HttpContext $httpContext,
-        StoreCookieManagerInterface $storeCookieManager,
-        AreaList $areaList = null,
-        State $appState = null
+        StoreCookieManagerInterface $storeCookieManager
     ) {
         $this->storeManager = $storeManager;
         $this->httpContext = $httpContext;
         $this->storeCookieManager = $storeCookieManager;
-        $this->areaList = $areaList ?? ObjectManager::getInstance()->get(AreaList::class);
-        $this->appState = $appState ?? ObjectManager::getInstance()->get(State::class);
     }
 
     /**
@@ -87,10 +67,6 @@ public function processHeaderValue(string $headerValue) : void
             $this->storeManager->setCurrentStore($storeCode);
             $this->updateContext($storeCode);
         }
-
-        // Load translations for the app
-        $area = $this->areaList->getArea($this->appState->getAreaCode());
-        $area->load(AreaInterface::PART_TRANSLATE);
     }
 
     /**

app/code/Magento/StoreGraphQl/Plugin/LocalizeEmail.php

@@ -0,0 +1,78 @@
+<?php
+
+namespace Magento\StoreGraphQl\Plugin;
+
+use Magento\Framework\App\AreaInterface;
+use Magento\Framework\App\AreaList;
+use Magento\Framework\App\State;
+use Magento\Framework\Exception\LocalizedException;
+use Magento\Framework\Exception\NoSuchEntityException;
+use Magento\Framework\Mail\Template\TransportBuilder;
+use Magento\Store\Model\App\Emulation;
+use Magento\Store\Model\StoreManagerInterface;
+
+/**
+ * Emulate the correct store when GraphQL is sending an email
+ */
+class LocalizeEmail
+{
+    /**
+     * @var StoreManagerInterface
+     */
+    private $storeManager;
+
+    /**
+     * @var Emulation
+     */
+    private $emulation;
+
+    /**
+     * @var AreaList
+     */
+    private $areaList;
+
+    /**
+     * @var State
+     */
+    private $appState;
+
+    /**
+     * @param StoreManagerInterface $storeManager
+     * @param Emulation $emulation
+     * @param AreaList $areaList
+     * @param State $appState
+     */
+    public function __construct(
+        StoreManagerInterface $storeManager,
+        Emulation $emulation,
+        AreaList $areaList,
+        State $appState
+    ) {
+        $this->storeManager = $storeManager;
+        $this->emulation = $emulation;
+        $this->areaList = $areaList;
+        $this->appState = $appState;
+    }
+
+    /**
+     * Emulate the correct store during email preparation
+     *
+     * @param TransportBuilder $subject
+     * @param \Closure $proceed
+     * @return mixed
+     * @throws NoSuchEntityException|LocalizedException
+     */
+    public function aroundGetTransport(TransportBuilder $subject, \Closure $proceed)
+    {
+        // Load translations for the app
+        $area = $this->areaList->getArea($this->appState->getAreaCode());
+        $area->load(AreaInterface::PART_TRANSLATE);
+
+        $currentStore = $this->storeManager->getStore();
+        $this->emulation->startEnvironmentEmulation($currentStore->getId());
+        $output = $proceed();
+        $this->emulation->stopEnvironmentEmulation();
+
+        return $output;
+    }
+}

app/code/Magento/StoreGraphQl/Plugin/StoreResolver.php

@@ -23,7 +23,7 @@
             </argument>
         </arguments>
     </type>
-    <type name="Magento\Store\Model\Resolver\Store">
-        <plugin name="graphQlLocalizationStoreResolver" type="Magento\StoreGraphQl\Plugin\StoreResolver" />
+    <type name="Magento\Framework\Mail\Template\TransportBuilder">
+        <plugin name="graphQlEmulateEmail" type="Magento\StoreGraphQl\Plugin\LocalizeEmail" />
     </type>
 </config>