\Magento\Quote\Api\CartItemRepositoryInterface::save method doesn't save passed cartItem

[ytorbyk]

Preconditions

Magento 2.1

Steps to reproduce

1. Create extension_attribute for \Magento\Quote\Api\Data\CartItemInterface - my_attribute
2. Create \Magento\Quote\Api\Data\CartItemInterface $cartItem
3. Assign my_attribute to $cartItem with any value
4. Pass the $cartItem to \Magento\Quote\Api\CartItemRepositoryInterface::save method

Expected result

1. The cartItem is added to the cart with all assigned extension_attributes.

Actual result

1. Only BuyRequest data is taken from the passed $cartItem and is used for creating new instance of \Magento\Quote\Api\Data\CartItemInterface which is added to the cart. (This logic is in \Magento\Quote\Model\Quote\Item\CartItemPersister::save method).

Moreover, if you load existing cartItem, assign an extension_attribute to the cartItem and pass it to the \Magento\Quote\Api\CartItemRepositoryInterface::save method then cartItem will not be updated. Only BuyRequest will be taken from the passed cartItem for updating of exiting cartItem.

Simular problem with product_option of cart item. It's possible to create extension_attributes for product option (or use custom_options) but it is impossible to add your own logic as CartItemProcessor.

[fooman]

I think with extension attributes you need to supply the code yourself to save, store and otherwise process the value. For example take a look at

https://github.com/magento/magento2/blob/2.1.0/app/code/Magento/Bundle/etc/extension_attributes.xml

and then this plugin:

https://github.com/magento/magento2/blob/2.1.0/app/code/Magento/Bundle/Model/Plugin/QuoteItem.php#L31

[ytorbyk]

Yes, I know about this.
As I described in initial topic there is no ability to do that.
You can pass product_option as extended attribute of cart item and custom_options, configurable_item_options or bundle_options as extended attributes of product_option.
Only this data will be taken from the passed cart items and used as BuyRequest data for updating/creating of cart items.
https://github.com/magento/magento2/blob/2.1.0/app/code/Magento/Quote/Model/Quote/Item/CartItemPersister.php#L69
https://github.com/magento/magento2/blob/2.1.0/app/code/Magento/Quote/Model/Quote/Item/CartItemPersister.php#L69

All other extended attributes (custom extended attributes) will be lost and there is not ability to save them.

The BuyRequest data is built by CartItemOptionsProcessor. There are hardcoded custom_options processor for all prodcuts and special processors for each type of products (except simple product). There is no ability to specify custom processor.

As solution I used plugin for \Magento\Quote\Model\Quote\Item\CartItemOptionsProcessor and there I process my extended attribute. However I don't think it's a good solution, sure there should be more elegant solution.

[SerhiyShkolyarenko]

Hi Yuriy!
my_attribute value have to be set through setExtensionAttributes() method, but not directly to the quote item object. To check that everything works properly let's modify 2 files in GiftMessage module:

1. Add the following code to code/Magento/GiftMessage/etc/extension_attributes.xml
   <extension_attributes for="Magento\Quote\Api\Data\CartItemInterface"> <attribute code="my_attribute" type="string" /> </extension_attributes>

2. Modify constructor and get method of code/Magento/GiftMessage/Model/ItemRepository.php to the state:
   ` public function __construct(
   \Magento\Quote\Api\CartRepositoryInterface $quoteRepository,
   \Magento\Store\Model\StoreManagerInterface $storeManager,
   \Magento\GiftMessage\Model\GiftMessageManager $giftMessageManager,
   \Magento\GiftMessage\Helper\Message $helper,
   \Magento\Quote\Api\CartItemRepositoryInterface $cartItemRepository,
   \Magento\Quote\Api\Data\CartItemExtensionFactory $cartItemExtensionFactory,
   \Magento\GiftMessage\Model\MessageFactory $messageFactory
   ) {
   $this->quoteRepository = $quoteRepository;
   $this->giftMessageManager = $giftMessageManager;
   $this->storeManager = $storeManager;
   $this->helper = $helper;
   $this->cartItemRepository = $cartItemRepository;
   $this->cartItemExtensionFactory = $cartItemExtensionFactory;
   $this->messageFactory = $messageFactory;
   }

   public function get($cartId, $itemId)
   {
   $quote = $this->quoteRepository->getActive($cartId);
   $quoteItem = $quote->getItemById($itemId);
   $extensionAttributes = $quoteItem->getExtensionAttributes();
   if ($extensionAttributes == null) {
   $extensionAttributes = $this->cartItemExtensionFactory->create();
   }
   $extensionAttributes->setMyAttribute('amazingValue');
   $quoteItem->setExtensionAttributes($extensionAttributes);
   $this->cartItemRepository->save($quoteItem);
   return $quoteItem->getExtensionAttributes()->getMyAttribute();
   }
   `

3. Clean Magento var/ directory.

4. Run GET request to /V1/carts/11/gift-message/12 with your cart id and cart item id.

For me this request returned "amazingValue" as expected.
Does it work for you in the same way?

[SerhiyShkolyarenko]

To process the value of extension attribute you need to create plugins to \Magento\Quote\Model\Quote\Item\Repository getList() and save() methods.

[ytorbyk]

Hi thank you for response,
In your example really it works fine.

However, the save method of cart item repository returns saved item and the item doesn't have any extended attributes.
$savedQuoteItem = $this->cartItemRepository->save($quoteItem);
return $savedQuoteItem->getExtensionAttributes(); // null

[ytorbyk]

It looks like the plugin is needed not only for saving extended attributes to DB but even for transferring them from passed quote item to returned quote item.

[ytorbyk]

If it's okay then I'm okay with closing the issue.

[SerhiyShkolyarenko]

$this->cartItemRepository->save() returns another object and some properties will be absent there.