Magento – Allow only one qty of item into cart in Magento 2

addtocartcontrollersmagento2product

I have created a custom controller in my module and calling via ajax to add the item to cart.

Below is my controller code.

<?php 

 namespace {Vendor}\{Module}\Controller\Product;                           
 class AddProduct extends \Magento\Framework\App\Action\Action                 
{
 protected $formKey;
 protected $cart;
 protected $product;
 protected $checkoutSession;
 public function __construct(
 \Magento\Framework\App\Action\Context $context,
 \Magento\Framework\Data\Form\FormKey $formKey,
 \Magento\Checkout\Model\Cart $cart,
 \Magento\Catalog\Model\ProductFactory $product,
 \Magento\Checkout\Model\Session $checkoutSession,
 array $data = []) {
  $this->formKey = $formKey;
  $this->cart = $cart;
  $this->product = $product;
  $this->checkoutSession = $checkoutSession;
  parent::__construct($context);
  }
  public function execute()
  {
  $productId = 1;
  $customPrice = 150;
  $params = array(
    'form_key' => $this->formKey->getFormKey(),
    'product_id' => $productId, //product Id
    'qty'   => 1 //quantity of product
  );
  $_product = $this->product->create()->load($productId);
  $this->cart->addProduct($_product, $params);

  $productItem = $this->getProductQuote($_product);
  $productItem->setCustomPrice($customPrice);
  $productItem->setOriginalCustomPrice($customPrice);
  //Enable super mode on the product.
  $productItem->getProduct()->setIsSuperMode(true);
  $this->cart->save();
  echo "success";
 }


 public function getProductQuote($product)
 {
  $quote = $this->checkoutSession->getQuote();
  $cartItems = $quote->getItemByProduct($product);
  return $cartItems;
 } 
}

The above code adds the product of qty 1 to the cart with a custom price whenever it is called.

I want to add only 1 qty of product to the cart. suppose if its called two or three times, only one qty should be present in cart. Need to remove previously added qty from the cart.

Is something can be done programmatically? There is a product setting in backend "Maximum qty allowed in cart", we can set this value but I am looking for the code how it can be done programmatically.

Can anyone look into it and help me, please. Thanks

Best Answer

You can use getItemByProduct

If Item is exist -> use addProduct function -> else -> use updateItem function

$item = $this->cart->getQuote()->getItemByProduct($_product);
if ($item) {
    $this->cart->addProduct($_product, $params);
} else {
    $this->cart->updateItem($item->getId(), 1);
}

Related Solutions

Call Model Method from Controller in Magento 2

The object manager is not the correct way to do this. Use dependency injection via the constructor whenever possible.

You are getting that error because your controller extends another class, but you are not following the parent class's constructor, or you did not clear the cache.

You have not provided your code, but I assume your controller extends \Magento\Framework\App\Action\Action. If you open that, you'll see the constructor signature for that class is:

/**
 * @param \Magento\Framework\App\Action\Context $context
 */
public function __construct(
    \Magento\Framework\App\Action\Context $context
) {
    // ...
}

You're getting the error because Magento is trying to inject a Context object, and you're asking for a Customer. To inject your model, your class constructor needs to look like this:

protected $customer;

/**
 * @param \Magento\Framework\App\Action\Context $context
 * @param \Demo\HelloWorld\Model\Customer $customer
 */
public function __construct(
    \Magento\Framework\App\Action\Context $context,
    \Demo\HelloWorld\Model\Customer $customer
) {
    $this->customer = $customer;

    parent::__construct($context);
}

Make that change, then flush the Magento cache (or folder var/cache), and then it should work.

Note: This is assuming your Customer class is injectable. If it's loaded from the database, you need to inject CustomerFactory instead, and then call $customer = $this->customerFactory->create().

Magento 2.1 – Use urlBuilder->getUrl() in Custom Module Controller

If your controller extend Magento\Framework\App\Action\Action you should follow rules of creation of the controller. So you should implement dependency injection of the parent class constructor (Magento\Framework\App\Action\Action):

/**
 * @param Context $context
 */
public function __construct(Context $context)
{
    parent::__construct($context);
    $this->_objectManager = $context->getObjectManager();
    $this->_eventManager = $context->getEventManager();
    $this->_url = $context->getUrl();
    $this->_actionFlag = $context->getActionFlag();
    $this->_redirect = $context->getRedirect();
    $this->_view = $context->getView();
    $this->messageManager = $context->getMessageManager();
}

Your construct method should look like this after a modifications:

/**
 * @param Context $context
 * @param UrlInterface $urlBuilder
 */
public function __construct(
    Context $context,
    UrlInterface $urlBuilder
) {
    parent::__construct($context);
    $this->urlBuilder = $urlBuilder;
}

NOTE: do not forget to remove old var/generation directory after implementing of modifications, because there are stored the generated files of controllers.

Best Answer

Related Solutions

Call Model Method from Controller in Magento 2

Magento 2.1 – Use urlBuilder->getUrl() in Custom Module Controller

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