Magento 2.2: What controllers are called when a product is added to the cart?

Question

I have the next error when a product is added to the cart:

Requested product doesn't exist

This comes from the following method:

\Magento\Catalog\Model\ProductRepository

 public function getById($productId, $editMode = false, $storeId = null, $forceReload = false)
    {
        $cacheKey = $this->getCacheKey([$editMode, $storeId]);
        if (!isset($this->instancesById[$productId][$cacheKey]) || $forceReload) {
            $product = $this->productFactory->create();
            if ($editMode) {
                $product->setData('_edit_mode', true);
            }
            if ($storeId !== null) {
                $product->setData('store_id', $storeId);
            }
            $this->logger->debug('Repo2' . $productId);
            $product->load($productId); //            $this->logger->debug(var_export(get_class_methods($product), true));
            if ($productId == '') {
                return nulL;
            }
            if (!$product->getId()) {
                throw new NoSuchEntityException(__('Requested product doesn\'t exist'));
            }
            $this->cacheProduct($cacheKey, $product);
        }
        return $this->instancesById[$productId][$cacheKey];
    }

With the logger I see that three calls are made and the third the $productId has no value and skip the exception

log:

I need to know where the third call is made to see the values it sends.

EDIT:

I have found the third call, it is at the time of validating the sales-rule:

This returns a null object:

$product = $model->getProduct();

\Magento\SalesRule\Model\Rule\Condition\Product

public function validate(\Magento\Framework\Model\AbstractModel $model)
    {
        //@todo reimplement this method when is fixed MAGETWO-5713
        /** @var \Magento\Catalog\Model\Product $product */

        $product = $model->getProduct();
        $this->logger->debug(var_export(get_class_methods($product), true));
        if (!$product instanceof \Magento\Catalog\Model\Product) {
            $product = $this->productRepository->getById($model->getProductId());
        }

        $product->setQuoteItemQty(
            $model->getQty()
        )->setQuoteItemPrice(
            $model->getPrice() // possible bug: need to use $model->getBasePrice()
        )->setQuoteItemRowTotal(
            $model->getBaseRowTotal()
        );

        $attrCode = $this->getAttribute();

        if ($attrCode === 'category_ids') {
            return $this->validateAttribute($this->_getAvailableInCategories($product->getId()));
        }

        if ($attrCode === 'quote_item_price') {
            $numericOperations = $this->getDefaultOperatorInputByType()['numeric'];
            if (in_array($this->getOperator(), $numericOperations)) {
                $this->setData('value', $this->getFormattedPrice($this->getValue()));
            }
        }

        return parent::validate($product);
    }

I have the same error but if I comment all the code and return directly true it is possible to add products to the checkout. But it is not a good solution since here it validates the offers.

Answer 1

Controller are called when product is add to cart.

Magento\Checkout\Controller\Cart

And this is the action controller.

Magento\Checkout\Controller\Cart\Add

The message 'Requested product doesn't exist' is triggered whenever Magento 2 tries to load a product which does not have a SKU.

To check which products do not have a SKU, sort the table catalog_product_entity by SKU. All the products with no SKU will then be grouped together. You can then fix this issue by manually adding the SKUs to the products in this table (though don't make a habit of directly editing the database - that way madness lies).

For more reference check below link

1. community.magento.com
2. magento.stackexchange.com

I hope it helps!