setInStock example

protected $entityManager;

    public function __construct(ModelManager $entityManager)
    {
        $this->entityManager = $entityManager;
    }

    public function addProductDetail(OrderDetail $detail): void
    {
        $product = $this->getProductFromDetail($detail);
        if ($product) {
            $product->setInStock($product->getInStock() - $detail->getQuantity());
            $this->entityManager->persist($product);
            $this->entityManager->flush($product);
        }
    }

    public function updateProductDetail(OrderDetail $detail, ?string $oldProductNumber = null, ?int $oldQuantity = null, ?string $newProductNumber = null, ?int $newQuantity = null): void
    {
        $oldQuantity = $oldQuantity === 0 || $oldQuantity > 0 ? $oldQuantity : $detail->getQuantity();
        $newQuantity = $newQuantity === 0 || $newQuantity > 0 ? $newQuantity : $detail->getQuantity();

        // If the position product has been changed, the old product stock must be increased based on the (old) ordering quantity.

if (!$esd) {
            $this->View()->assign([
                'success' => false,
                'message' => sprintf('ESD by id %s not found', $esdId),
            ]);

            return;
        }

        $freeSerialsCount = $this->getFreeSerialCount($esdId);
        $variant = $esd->getArticleDetail();
        $variant->setInStock($freeSerialsCount);

        $esd->fromArray($this->Request()->getPost());
        $this->getManager()->flush();

        $this->View()->assign([
            'data' => $this->Request()->getPost(),
            'success' => true,
        ]);
    }

    /** * Event listener function of the product backend module. * Will be fired when the user deletes ESD */

        $entityManager = $this->get(ModelManager::class);

        $products = $this->getProductsOfOrder($orderModel);

        foreach ($products as $product) {
            $position = $this->getOrderPositionByProduct($product, $orderModel);
            if (!$position) {
                continue;
            }

            $product->setInStock(
                $product->getInStock() - $position->getQuantity()
            );

            $entityManager->persist($product);
        }
    }

    /** * Helper function to check if the stock is valid if the article is on sale */
    private function isValidStock(ProductVariant $variant, int $newStock): bool
    {