Magento 2 I want to set a custom price of a product programmatically but only for this one session

Question

I have a little problem because I first add some products into the cart -> this is working. But I also need to change the price of this products I add. The problem about that is, that I only want to change the price for this session. Afterwards the price should be the same as before.

(EDIT) One other idea would be to add a custom temporary discount price but not a discount of coupon code in the controller. Any Idea?

I tried this two solutions already: https://magento.stackexchange.com/a/216111/82120

https://webkul.com/blog/magento2-set-custom-price-of-product/

But none of them did work.

This is my code at the Moment:

Controller.php:

<?php
namespace MassiveArt\ShoppingCart\Controller\Index;
use Magento\Framework\App\Action\Action;
use Magento\Framework\App\Action\Context;
use Magento\Framework\Data\Form\FormKey;
use Magento\Framework\Controller\Result\JsonFactory;
use Magento\Checkout\Model\Cart;
use Magento\Catalog\Model\Product;

class Index extends Action
{
    protected $formKey;
    protected $checkoutSession;
    protected $cart;
    protected $product;
    public function __construct(
       Context $context,
       \Magento\Checkout\Model\Session $checkoutSession,
         JsonFactory $resultJsonFactory,
       FormKey $formKey,
       Cart $cart,
       Product $product) {
            $this->checkoutSession = $checkoutSession;
            $this->formKey = $formKey;
               $this->resultJsonFactory = $resultJsonFactory;
            $this->cart = $cart;
            $this->product = $product;
            parent::__construct($context);
    }
    public function execute()
    {

        try {
             $result = $this->resultJsonFactory->create();
           $productId = $this->getRequest()->getParam('productId');
           $amount = $this->getRequest()->getParam('amount');
           $test = $this->getRequest()->getParam('test');
           if($test == "set"){
               $allItems = $this->checkoutSession->getQuote()->getAllVisibleItems();
               foreach ($allItems as $item) {
                   $itemId = $item->getItemId();
                   $this->cart->removeItem($itemId);
               }
            }
               $params = array(
                    'form_key' => $this->formKey->getFormKey(),
                    'product' => $productId,
                    'qty'   => $amount,
            );
              $product = $this->product->load($productId);

            // Here I want to change the price

            $product->save();
              $this->cart->addProduct($product, $params);
              $this->cart->save();
                $result->setData(['message' => __("Product is added in cart")]);
            return $result;
       } catch(\Exception $e) {
               $result->setData(['error' => __($e->getMessage())]);
               return $result;
         }
 }
}

If you need to have any more information to solve this answer, please let me know.

Answer 1

Id recommend using an observer event for this rather than trying to execute it within a controller. with the below code you can hook into the add to cart action and update the product price as it is added to the basket.

VendorName/ModuleName/etc/frontend/events.xml

<?xml version="1.0"?>
<config xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="urn:magento:framework:Event/etc/events.xsd">
    <event name="checkout_cart_product_add_after">
        <observer name="module_customprice" instance="VendorName\ModuleName\Observer\CustomPrice" />
    </event>
</config>

VendorName/ModuleName/Observer/CustomSessionPrice

namespace VendorName\ModuleName\Observer;

use Magento\Framework\Event\ObserverInterface;
use Magento\Framework\App\RequestInterface;

class CustomSessionPrice implements ObserverInterface
{
    public function execute(\Magento\Framework\Event\Observer $observer) {

        $customer = $observer->getEvent()->getCustomer();
        if(!empty($customer->getId())) {
             $item = $observer->getEvent()->getData('quote_item');          
             $item = ( $item->getParentItem() ? $item->getParentItem() : $item );

             $item->setCustomPrice(100);
             $item->setOriginalCustomPrice(100);
             $item->getProduct()->setIsSuperMode(true);
        }

    }

}

If you wish to do via ajax you will need to amend your code like so

<?php

namespace MassiveArt\ShoppingCart\Controller\Index;

use Magento\Framework\App\Action\Action;
use Magento\Framework\App\Action\Context;
use Magento\Framework\Data\Form\FormKey;
use Magento\Framework\Controller\Result\JsonFactory;
use Magento\Checkout\Model\Cart;
use Magento\Catalog\Model\Product;

class Index extends Action
{
    /**
     * @var FormKey
     */
    protected $formKey;

    /**
     * @var Session
     */
    protected $checkoutSession;

    /**
     * @var Cart
     */
    protected $cart;

    /**
     * @var Product
     */
    protected $product;

    /**
     * Constructor.
     *
     * @param Context $context
     * @param \Magento\Checkout\Model\Session $checkoutSession
     * @param \Magento\Customer\Model\Session $customerSession
     * @param JsonFactory $resultJsonFactory
     * @param FormKey $formKey
     * @param Cart $cart
     * @param Product $product
     */
    public function __construct(
        Context $context,
        \Magento\Checkout\Model\Session $checkoutSession,
        \Magento\Customer\Model\Session $customerSession,
        JsonFactory $resultJsonFactory,
        FormKey $formKey,
        Cart $cart,
        Product $product
    ) {
        $this->checkoutSession = $checkoutSession;
        $this->customerSession = $customerSession;
        $this->formKey = $formKey;
        $this->resultJsonFactory = $resultJsonFactory;
        $this->cart = $cart;
        $this->product = $product;
        parent::__construct($context);
    }

    public function execute()
    {

        try {

            // Set result data and pass back
            $result = $this->resultJsonFactory->create();

            if(!$this->customerSession->getCustomer()->getId()) {
                $result->setData(['error' => __('Invalid session ID')]);
            }

            // Get parameters
            $productId = $this->getRequest()->getParam('productId');
            $amount = $this->getRequest()->getParam('amount');
            $test = $this->getRequest()->getParam('test');

            if($test == "set"){
                $allItems = $this->checkoutSession->getQuote()->getAllVisibleItems();
                foreach ($allItems as $item) {
                    $itemId = $item->getItemId();
                    $this->cart->removeItem($itemId);
                }
            }

            // Load product by ID
            $product = $this->product->load($productId);

            // New product params
            $params = array(
                'form_key' => $this->formKey->getFormKey(),
                'product' => $productId,
                'qty'   => $amount,
                'price' => '100'
            );

            // Save Product
            $product->save();

            // Add product to cart and save
            $this->cart->addProduct($product, $params);
            $this->cart->save();

            $result->setData(['message' => __("Product is added in cart")]);

            return $result;
        } catch(\Exception $e) {
            $result->setData(['error' => __($e->getMessage())]);
            return $result;
        }
    }
}