Added super_group extension attribute to Magento\Quote\Api\Data\ProductOptionInterface to allow user to send associated product quantities when adding to cart via REST API

Added a 'grouped' cartItemProcessors to the Magento\Quote\Model\Quote\Item\Repository to reformat the super_group extension attribute into a format that is compatible with buy request

Author: Shawn Abramson

app/code/Magento/GroupedProduct/Api/Data/GroupedItemQtyInterface.php

@@ -0,0 +1,33 @@
+<?php
+
+namespace Magento\GroupedProduct\Api\Data;
+
+interface GroupedItemQtyInterface extends \Magento\Framework\Api\ExtensibleDataInterface
+{
+    const PRODUCT_ID = 'product_id';
+    const QTY        = 'qty';
+
+    /**
+     * Associated product id
+     *
+     * @param int|string $value
+     */
+    public function setProductId($value);
+
+    /**
+     * Associated product id
+     *
+     * @return int|string
+     */
+    public function getProductId();
+
+    /**
+     * @param int|string $qty
+     */
+    public function setQty($qty);
+
+    /**
+     * @return int
+     */
+    public function getQty();
+}

app/code/Magento/GroupedProduct/Model/Quote/Item/CartItemProcessor.php

@@ -0,0 +1,70 @@
+<?php
+
+namespace Magento\GroupedProduct\Model\Quote\Item;
+
+use Magento\Framework\DataObject\Factory as ObjectFactory;
+use Magento\Quote\Api\Data\CartItemInterface;
+use Magento\Quote\Api\Data\ProductOptionInterface;
+use Magento\Quote\Model\Quote\Item\CartItemProcessorInterface;
+
+/**
+ * Class CartItemProcessor
+ */
+class CartItemProcessor implements CartItemProcessorInterface
+{
+    /**
+     * @var ObjectFactory
+     */
+    protected $objectFactory;
+
+    /**
+     * CartItemProcessor constructor.
+     *
+     * @param ObjectFactory $objectFactory
+     */
+    public function __construct(ObjectFactory $objectFactory)
+    {
+        $this->objectFactory = $objectFactory;
+    }
+
+    /**
+     * @param CartItemInterface $cartItem
+     *
+     * @return \Magento\Framework\DataObject|null
+     */
+    public function convertToBuyRequest(CartItemInterface $cartItem)
+    {
+        $productOption = $cartItem->getProductOption();
+        if ($productOption instanceof ProductOptionInterface && $productOption->getExtensionAttributes()) {
+            $superGroup = $productOption->getExtensionAttributes()->getSuperGroup();
+            if (is_array($superGroup)) {
+                $requestData = [];
+
+                /** @var GroupedItemQty $item */
+                foreach ($superGroup as $item) {
+                    if (!isset($requestData['super_group'])) {
+                        $requestData['super_group'] = [];
+                    }
+
+                    $requestData['super_group'][$item->getProductId()] = $item->getQty();
+                }
+
+                if (!empty($requestData)) {
+                    return $this->objectFactory->create($requestData);
+                }
+            }
+        }
+
+        return null;
+    }
+
+    /**
+     * @param CartItemInterface $cartItem
+     *
+     * @return CartItemInterface
+     */
+    public function processOptions(CartItemInterface $cartItem)
+    {
+        return $cartItem;
+    }
+}

app/code/Magento/GroupedProduct/Model/Quote/Item/GroupedItemQty.php

@@ -0,0 +1,48 @@
+<?php
+
+namespace Magento\GroupedProduct\Model\Quote\Item;
+
+use Magento\Framework\Model\AbstractExtensibleModel;
+use Magento\GroupedProduct\Api\Data\GroupedItemQtyInterface;
+
+/**
+ * Class GroupedItemQty
+ */
+class GroupedItemQty extends AbstractExtensibleModel implements GroupedItemQtyInterface
+{
+    /**
+     * {@inheritdoc}
+     */
+    public function setProductId($value)
+    {
+        $this->setData(self::PRODUCT_ID, $value);
+
+        return $this;
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function getProductId()
+    {
+        return $this->getData(self::PRODUCT_ID);
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function setQty($qty)
+    {
+        $this->setData(self::QTY, $qty);
+
+        return $this;
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function getQty()
+    {
+        return (int)$this->getData(self::QTY);
+    }
+}

app/code/Magento/GroupedProduct/etc/di.xml

@@ -6,6 +6,8 @@
  */
 -->
 <config xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="urn:magento:framework:ObjectManager/etc/config.xsd">
+    <preference for="Magento\GroupedProduct\Api\Data\GroupedItemQtyInterface" type="Magento\GroupedProduct\Model\Quote\Item\GroupedItemQty" />
+
     <type name="Magento\Quote\Model\Quote\Item\RelatedProducts">
         <arguments>
             <argument name="relatedProductTypes" xsi:type="array">
@@ -105,4 +107,11 @@
             </argument>
         </arguments>
     </type>
+    <type name="Magento\Quote\Model\Quote\Item\Repository">
+        <arguments>
+            <argument name="cartItemProcessors" xsi:type="array">
+                <item name="grouped" xsi:type="object">Magento\GroupedProduct\Model\Quote\Item\CartItemProcessor\Proxy</item>
+            </argument>
+        </arguments>
+    </type>
 </config>

app/code/Magento/GroupedProduct/etc/extension_attributes.xml

@@ -9,4 +9,8 @@
     <extension_attributes for="Magento\Catalog\Api\Data\ProductLinkInterface">
         <attribute code="qty" type="float" />
     </extension_attributes>
+
+    <extension_attributes for="Magento\Quote\Api\Data\ProductOptionInterface">
+        <attribute code="super_group" type="Magento\GroupedProduct\Api\Data\GroupedItemQtyInterface[]" />
+    </extension_attributes>
 </config>