Programatically update cart item quantity

Question

Below is my code:

namespace Ves\Productlist\Controller\Cart;
use Magento\Quote\Model\QuoteRepository;
class CartUpdate extends \Magento\Framework\App\Action\Action
{
    protected $quoteRepository;

    public function __construct(
    \Magento\Quote\Api\CartRepositoryInterface $quoteRepository
    ) {
    $this->quoteRepository = $quoteRepository;
    }

    public function execute()
    {
    $objectManager = \Magento\Framework\App\ObjectManager::getInstance();
    $cart = $objectManager->get('\Magento\Checkout\Model\Cart'); 
echo $cartId=$cart->getQuote()->getId();

    $itemId = 720;
    $itemQty = 1;

    $quote = $this->quoteRepository->getActive($cartId);
    $cartitems->setquoteId($cartId);
    $cartitems->setitemId($itemId);
    $cartitems->setqty($itemQty);

    $quoteItems[] = $cartitems;
    $quote->setItems($quoteItems);
    $this->quoteRepository->save($quote);
    $quote->collectTotals();

    }

}

But I am getting the below error:

Answer 1

Change Your construct as per below code :

namespace Ves\Productlist\Controller\Cart;

use Magento\Quote\Model\QuoteRepository;

class CartUpdate extends \Magento\Framework\App\Action\Action
{
    protected $quoteRepository;


    public function __construct(
        \Magento\Framework\App\Action\Context $context,
        \Magento\Quote\Api\CartRepositoryInterface $quoteRepository
    ) {
        $this->quoteRepository = $quoteRepository;
        parent::__construct($context);
    }

    public function execute()
    {
        $objectManager = \Magento\Framework\App\ObjectManager::getInstance();
        $cart = $objectManager->get('\Magento\Checkout\Model\Cart'); 
        echo $cartId=$cart->getQuote()->getId();

        $itemId = 720;
        $itemQty = 1;

        $quote = $this->quoteRepository->getActive($cartId);
        $cartitems = $cart->getQuote()->getAllItems();
        $cartitems->setquoteId($cartId);
        $cartitems->setitemId($itemId);
        $cartitems->setqty($itemQty);

        $quoteItems[] = $cartitems;
        $quote->setItems($quoteItems);
        $this->quoteRepository->save($quote);
        $quote->collectTotals();

    }

}

After changing your code go to terminal and fire the below command.

cd /yourMagentoPath
php bin/magento setup:di:compile

Answer 2

Try this Code

namespace Ves\Productlist\Controller\Cart;
use Magento\Quote\Model\QuoteRepository;
class CartUpdate extends \Magento\Framework\App\Action\Action
{
    protected $quoteRepository;

    public function __construct(
        \Magento\Backend\App\Action\Context $context,
        \Magento\Quote\Api\CartRepositoryInterface $quoteRepository
    ) {
        parent::__construct($context);
        $this->quoteRepository = $quoteRepository;
    }

    public function execute()
    {
        $objectManager = \Magento\Framework\App\ObjectManager::getInstance();
        $cart = $objectManager->get('\Magento\Checkout\Model\Cart'); 
        echo $cartId=$cart->getQuote()->getId();

        $itemId = 720;
        $itemQty = 1;

        $quote = $this->quoteRepository->getActive($cartId);
        $cartitems->setquoteId($cartId);
        $cartitems->setitemId($itemId);
        $cartitems->setqty($itemQty);

        $quoteItems[] = $cartitems;
        $quote->setItems($quoteItems);
        $this->quoteRepository->save($quote);
        $quote->collectTotals();

    }

}

please remove generated and cache after check

Answer 3

public function __construct(
    \Magento\Backend\App\Action\Context $context,
    \Magento\Quote\Api\CartRepositoryInterface $quoteRepository
) {
    parent::__construct($context);
    //setting quote repos into variable
    $this->quoteRepository = $quoteRepository;
}

public function execute()
{   
    $objectManager = \Magento\Framework\App\ObjectManager::getInstance();
    //populate cart class
    $cart = $objectManager->get('\Magento\Checkout\Model\Cart'); 
    echo $cartId=$cart->getQuote()->getId();

    //setting item id and qty for cart 
    $itemId = 12;
    $itemQty = 2;

    $quote = $this->quoteRepository->getActive($cartId);
    $cartitems->setquoteId($cartId);
    $cartitems->setitemId($itemId);
    $cartitems->setqty($itemQty);

    $quoteItems[] = $cartitems;
    $quote->setItems($quoteItems);
    $this->quoteRepository->save($quote);
    $quote->collectTotals();

}

Answer 4

Try this code

<?php

namespace VendoreName\ModuleName\Controller\Index;

use Magento\Framework\App\Action\Action;
use Magento\Framework\Controller\ResultFactory;

class Editcart extends \Magento\Framework\App\Action\Action
{
    protected $resultPageFactory;
    protected $request;
    protected $cart;

    public function __construct(
        \Magento\Framework\App\Action\Context $context,
        \Magento\Framework\View\Result\PageFactory $resultPageFactory,
        \Magento\Checkout\Model\Cart $cart,
        \Magento\Framework\App\Request\Http $Request

    ) {
        $this->resultPageFactory = $resultPageFactory;
        $this->request = $request;
        $this->cart = $cart;
        parent::__construct($context);
    }

    public function execute()
    {
        $resultRedirect = $this->resultFactory->create(ResultFactory::TYPE_REDIRECT);
        // get cart product data
        $data = $this->request->getParams();
        ///$data['quoteid'] is current qoute item id
        // $data['prdid'] is product id
        if (!isset($data['quoteid'])) {
            $this->messageManager->addError(__('Invalid product data.'));
            $resultRedirect->setUrl($this->_redirect->getRefererUrl());
            return $resultRedirect;
        }
        // get quote product by items id
        try {
            $quote_data = $this->cart->getQuote()->getItemById($data['quoteid']);

            if (!$quote_data) {
                throw new \Magento\Framework\Exception\LocalizedException(__('We can\'t find the quote item.'));
            }

            $quote_params = $quote_data->getBuyRequest();

            // update product data
            if (isset($data['super_attribute'])) {
                $quote_params->setSuperAttribute($data['super_attribute'][$data['prdid']]);
            } elseif (isset($data['links'])) {
                $quote_params->setLinks($data['links']);
            } elseif ((isset($data['bundle_option'])) && (isset($data['bundle_option_qty']))) {
                $quote_params->setBundleOption($data['bundle_option']);
                $quote_params->setBundleOptionQty($data['bundle_option_qty']);
            } else {
                $quote_params = $quote_data->getBuyRequest();
            }

            //update custom options
            if (isset($data['options'])) {
                $quote_params->setOptions($data['options']);
            }

            // update qty
            $quote_params->setQty($data['prdqty']);

            // update product data with qty
            $item = $this->cart->getQuote()->updateItem($data['quoteid'], $quote_params);

            if (is_string($item)) {
                throw new \Magento\Framework\Exception\LocalizedException(__($item));
            }
            if ($item->getHasError()) {
                throw new \Magento\Framework\Exception\LocalizedException(__($item->getMessage()));
            }
            // save cart item
            $this->cart->save();
            $this->messageManager->addSuccessMessage(__('Product has been successfully updated.'));
        } catch (\Magento\Framework\Exception\LocalizedException $e) {
            $this->messageManager->addNoticeMessage($e->getMessage());
        } catch (Exception $e) {
            $this->messageManager->addExceptionMessage($e, __('We can\'t update the item right now.'));
        }
        $resultRedirect->setUrl($this->_redirect->getRefererUrl());
        return $resultRedirect;
    }
}

I Hope This Helps You.