Check products in cart if they are out of stock before place order REST API : Magento 2

Question

I am building mobile application using Magento 2, I had an old defined cart which had a product and when checking out it gives an error saying the item is out of stock, that happened after payment and placing the order. I checked this product in backend and found its Quantity was 0 and out of stock. checked with my friend and knew that he bought it in a test case.

Ho can I fix this problem and check all products in cart are in stock OR out of stock Using REST API?

Answer 1

I am not sure I understand your question but you can add a new extension attributes that check stock status in rest/V1/carts/mine/items and display the appropriate message.

Create your extension attribute in Vendor/ModuleName/etc/webapi_rest/extension_attributes.xml

<extension_attributes for="Magento\Quote\Api\Data\CartItemInterface">
    <attribute code="stock" type="string" />
</extension_attributes>

Then Create your plugin to overwrite Magento\Quote\Model\Quote\Item\Repository::getList

<?xml version="1.0"?>

<config xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="urn:magento:framework:ObjectManager/etc/config.xsd">
    <type name="Magento\Quote\Model\Quote\Item\Repository">
        <plugin name="stock" type="Vendor\ModuleName\Plugin\Stock" disabled="false" sortOrder="70"/>
    </type>
</config>

Then Create Stock.php in Vendor\ModuleName\Plugin\Stock.php

In Stock.php, we overwrite GetList with aroundplugin. We also get StockRegistryInterface to check If item is in stock by sku. Then we pass the message to our extension interface factory.

<?php
/**
 * Copyright © 2013-2017 Magento, Inc. All rights reserved.
 * See COPYING.txt for license details.
 */
namespace Vendor\ModuleName\Plugin;
use Magento\Quote\Model\Quote\Item\Repository as ItemRepository;

class Stock
{
    protected $quoteRepository;
    protected $cartItemExtensionFactory;
    protected $stockRegistry;


    public function __construct(
        \Magento\Quote\Api\CartRepositoryInterface $quoteRepository,
        \Magento\Quote\Api\Data\CartItemExtensionFactory $cartItemExtensionFactory,
        \Magento\CatalogInventory\Api\StockRegistryInterface $stockRegistry
    ) {
        $this->quoteRepository = $quoteRepository;
        $this->stockRegistry = $stockRegistry;
        $this->cartItemExtensionFactory = $cartItemExtensionFactory;
    }

    public function aroundGetList(ItemRepository $subject, \Closure $proceed, $cartId)
    {
        $cartItems = $proceed($cartId);
        /** @var  \Magento\Quote\Model\Quote $quote */
        $quote = $this->quoteRepository->getActive($cartId);

        /** @var \Magento\Quote\Api\Data\CartItemExtensionInterface $extensionAttributes */
          $i = 0;
        foreach ($quote->getAllVisibleItems() as $item) {
            $extensionAttributes = $cartItems[$i]->getExtensionAttributes();
            if ($extensionAttributes === null) {
                $extensionAttributes = $this->cartItemExtensionFactory->create();
            }
            $sku = $item->getSku();
            $stock = $this->stockRegistry->getStockItemBySku($sku)->getIsInStock();
            if ($stock) {
                $message = "Item In Stock";
            } else {
                $message = "Item Out Of Stock";
            }
            $extensionAttributes->setStock($message);
            $cartItems[$i]->setExtensionAttributes($extensionAttributes);
            $i++;
        }
       // $cartItems->setExtensionAttributes($extensionAttributes);

        return $cartItems;
    }
}

Thanks