feat ： order rest api 添加商图片url

app/code/Joshine/Sales/Plugin/OrderRepositoryPlugin.php

+<?php
+
+namespace Joshine\Sales\Plugin;
+
+use Magento\Catalog\Model\ProductFactory;
+use Magento\Sales\Api\Data\OrderInterface;
+use Magento\Sales\Api\Data\OrderItemExtensionFactory;
+use Magento\Sales\Api\Data\OrderItemExtensionInterface;
+use Magento\Sales\Api\OrderRepositoryInterface;
+use Magento\Sales\Api\Data\OrderItemInterface;
+use Magento\Sales\Api\Data\OrderItemSearchResultInterface;
+use Magento\Sales\Api\OrderItemRepositoryInterface;
+use Magento\Catalog\Helper\Image;
+
+/**
+ * Class OrderItemRepositoryPlugin
+ */
+class OrderRepositoryPlugin
+{
+    /**
+     * Order feedback field name
+     */
+    const FIELD_NAME = 'image_url';
+
+    /**
+     * @var OrderItemExtensionFactory
+     */
+    private $orderItemExtensionFactory;
+    /**
+     * @var OrderRepositoryInterface
+     */
+    private $orderRepository;
+    /**
+     * @var \Magento\Sales\Api\ProductRepositoryInterfaceFactory
+     */
+    private $productRepository;
+    /**
+     * @var \Magento\Catalog\Api\ProductRepositoryInterface
+     */
+    private $_productRepository;
+    /**
+     * @var Image
+     */
+    private $imageHelper;
+    /**
+     * @var ProductFactory
+     */
+    private $productFactory;
+
+    public function __construct(
+        OrderRepositoryInterface $orderRepository,
+        \Magento\Sales\Api\Data\OrderItemExtensionFactory $orderItemExtensionFactory,
+        \Magento\Catalog\Api\ProductRepositoryInterface $productRepository,
+        \Magento\Catalog\Helper\Image $imageHelper,
+        ProductFactory $productFactory
+    )
+    {
+        $this->orderItemExtensionFactory = $orderItemExtensionFactory;
+        $this->orderRepository    = $orderRepository;
+        $this->_productRepository = $productRepository;
+        $this->imageHelper        = $imageHelper;
+        $this->productFactory     = $productFactory;
+    }
+
+    public function afterGet(OrderRepositoryInterface $subject, OrderInterface $quote)
+    {
+        return $this->setAttributeValue($quote);
+    }
+
+    private function setAttributeValue($quote) {
+        foreach ($quote->getItems() as $item) {
+            $extensionAttributes = $item->getExtensionAttributes();
+            if ($extensionAttributes === null) {
+                $extensionAttributes = $this->orderItemExtensionFactory->create();
+            }
+            $extensionAttributes->setImage("null");
+            $product = $this->_productRepository->get($item->getSku());
+            if ($product) {
+                $objectManager = \Magento\Framework\App\ObjectManager::getInstance();
+                $storeManager = $objectManager->get('\Magento\Store\Model\StoreManagerInterface');
+                $hostname = $storeManager->getStore()->getBaseUrl();
+                $extensionAttributes->setImage($hostname."media/catalog/product/".$product->getData('thumbnail'));
+            }
+        }
+
+        return $quote;
+    }
+}
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app/code/Joshine/Sales/etc/di.xml

@@ -6,4 +6,7 @@
     <type name="\Magento\Sales\Block\Adminhtml\Order\View\Items">
     <type name="\Magento\Sales\Block\Adminhtml\Order\View\Items">
         <plugin name="order-item-sort" type="Joshine\Sales\Plugin\ItemsSortPlugin" sortOrder="1" />
         <plugin name="order-item-sort" type="Joshine\Sales\Plugin\ItemsSortPlugin" sortOrder="1" />
     </type>
     </type>
+    <type name="\Magento\Sales\Api\OrderRepositoryInterface">
+        <plugin name="add-items-image" type="Joshine\Sales\Plugin\OrderRepositoryPlugin" />
+    </type>
 </config>
 </config>
\ No newline at end of file

app/code/Joshine/Sales/etc/extension_attributes.xml

+<?xml version="1.0"?>
+<config xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+        xsi:noNamespaceSchemaLocation="urn:magento:framework:Api/etc/extension_attributes.xsd">
+    <extension_attributes for="Magento\Sales\Api\Data\OrderItemInterface">
+        <attribute code="image" type="string" />
+    </extension_attributes>
+</config>
\ No newline at end of file