Set custom price of product when adding to cart code not working

Question

I have write module for set custom price of product when adding to cart but my code not working.

     namespace Navin\Testcart\Observer;

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

        class CustomPrice implements ObserverInterface
        {
            public function invoke(\Magento\Framework\Event\Observer $observer) {
                //echo "test";exit();
                 $item=$observer->getEvent()->getData('quote_item');
                 $product=$observer->getEvent()->getData('product');
                $item = ( $item->getParentItem() ? $item->getParentItem() : $item );
                // Load the custom price
                $price = $product->getPrice()+10; // 10 is custom price. It will increase in product price.
                // Set the custom price
                $item->setCustomPrice($price);
                $item->setOriginalCustomPrice($price);
                // Enable super mode on the product.
                $item->getProduct()->setIsSuperMode(true);
            }

        }

Help for resolve my issue.

Please add more details about your issue? Which event you want to catch? — Khoa TruongDinh, Sep 23 '16 at 05:51

score 6 · Accepted Answer · edited Jan 21 '19 at 13:17

6

Please use this even checkout_cart_product_add_after, and also I suggest you that

ObserverInterface has only one method which is execute, so write your code in this method.

And do not use parent Item because while you are adding to cart any item then price depend upon child item so the best way is to use directly that item object that you are getting. So best practice is to use that item itself.

And also return $this object at the end of your code inside execute method.

For eg: namespace Navin\Testcart\Observer;

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

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

        $item=$observer->getEvent()->getData('quote_item');
        $product=$observer->getEvent()->getData('product');
        // here i am using item's product final price
        $price = $item->getProduct()->getFinalPrice()+10; // 10 is custom price. It will increase in product price.
        // Set the custom price
        $item->setCustomPrice($price);
        $item->setOriginalCustomPrice($price);
        // Enable super mode on the product.
        $item->getProduct()->setIsSuperMode(true);
        return $this;
    }

}

Hope this will help you. :)

edited Jan 21 '19 at 13:17

Utsav Gupta

1,243
1
18
48

answered Sep 23 '16 at 06:29

Rose Hale

76
3

not working i have try @Rose Hale – Navin Bhudiya Sep 23 '16 at 13:52
When i apply wrong coupon code product price become 0 in row total. If i apply again, price display correct. Do you know why this happen? It happen only first time. – user55548 Nov 19 '18 at 10:22
This is not work if when bundle product is in cart in magento-2.1 @Rose Hale. – Lovely Setia Nov 20 '18 at 10:34
1

Working.. Thanks @Rose Hale.. – Bharat Chodvadiya Apr 04 '19 at 05:45
hi @Rose, same code i am using in controller, its not working for me, here is my question,https://magento.stackexchange.com/questions/274172/quote-id-is-empty-when-inserting-multiple-records-into-cart-in-magento2 – Jafar Pinjar May 13 '19 at 15:17

score 2 · Answer 2 · answered Jan 31 '20 at 15:36

A before plugin for the Quote class' AddProduct function might be a better way to do what you're trying to do. From the devdocs, best practice is

Events SHOULD NOT change a state of observable objects.

whereas a plugin

is a class that modifies the behavior of public class functions by intercepting a function call and running code before, after, or around that function call. This allows you to substitute or extend the behavior of original, public methods for any class or interface.

Basically with a plugin you'd modify the price of the product before the quote object is created rather than changing the price of the quote object after it is created.

There's some good discussion about plugins vs observers and which is better. The general consensus seems to be that observers are a legacy Magento 1 thing whereas plugins are the new hotness, but both work. You can read more of the discussion here if you'd like.

Here's how you could do what you're after with a plugin.

Define the plugin in app/code/YourName/YourModule/etc/di.xml

<?xml version="1.0"?>
<config xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="urn:magento:framework:ObjectManager/etc/config.xsd">
<type name="Magento\Quote\Model\Quote">
    <plugin name="change_price_plugin" type="YourName\YourBuilder\Plugin\QuotePlugin"
            sortOrder="10" disabled="false"/>
</type>

Then in app/code/YourName/YourModule/Plugin/QuotePlugin.php

<?php

namespace YourName\YourModule\Plugin;

class QuotePlugin
{
    /**
     * @param \Magento\Quote\Model\Quote $subject
     * @param \Magento\Catalog\Model\Product $product
     * @param null|float|\Magento\Framework\DataObject $request
     * @param null|string $processMode
     * @throws \Exception
     * @return array
     */
    public function beforeAddProduct(
        $subject,
        $product,
        $request = null,
        $processMode = \Magento\Catalog\Model\Product\Type\AbstractType::PROCESS_MODE_FULL
    ){          
        $newPrice = $product->getFinalPrice() + 10;
        $product->setPrice($newPrice);
        $request['custom_price'] = $newPrice;

        return [$product, $request, $processMode];
    }       
}

This seems to be a best aproach to the solution but do you know why it doesn't work for grouped products? — Strife86, Oct 17 '20 at 03:47
Any idea about how can i add product custom special price(Sale price) the same waay? — Nafsss, Jan 08 '21 at 09:25

Himanshu · Answer 3 · 2020-02-04T06:20:00.300

public function execute(Observer $observer) {

    /** @var $item \Magento\Quote\Model\Quote\Item */       $item = $observer->getEvent()->getQuote()->getAllVisibleItems();        if ($item) {
            foreach ($item->getQuote()->getAllItems() as $bundleitems) {
                /** @var $bundleitems\Magento\Quote\Model\Quote\Item */
                //Skip the bundle product
                if ($bundleitems->getProduct()->getTypeId() == Type::TYPE_BUNDLE) {
                    continue;
                }
                $bundleitems->setCustomPrice(1.00);
                $bundleitems->setOriginalCustomPrice(1.00);
                $bundleitems->getProduct()->setIsSuperMode(true);

            }           }       return $this;   }

Set custom price of product when adding to cart code not working

3 Answers3

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