Magento – apply custom discount in cart magento2 via observer

magento2promotionssalesshopping-cart-price-rules

I have created a custom promotion in magento2. To get that working I needed to do some customization in cart which I am trying to do with salesrule_validator_process event.
I needed the rulename and discount values to be modified before applying in cart.

Now In Magento1 we used to update values as below:

$result = $observer['result'];

$result->setDiscountAmount($DiscountAmount);

$result->setBaseDiscountAmount($BaseDiscountAmount);

How we can achieve the same in Magento2?

Any thoughts/suggestions are welcome.

Best Answer

You can apply discount amount in magento2 by same event just write below code in your observer file:

$result = $observer->getEvent()->getResult();

$result->setAmount($DiscountAmoun);

$result->setBaseAmount($DiscountAmoun);

Related Solutions

Shopping Cart Price Rules – Apply Discount to One Item in Cart

Yes, there is no corresponding condition in the default magento shopping cart rules. And yes, there are some extensions at the magento connect. Search for "special promotions" or "advanced promotions" for example.

Basically, if you want to create a new module you can define a new action, similar to "fixed discount to whole cart" then observe event salesrule_validator_process and calculate total discount based on the first (say cheapest) product price. Take into account free shipping promo also.

The event is dispatched from app\code\core\Mage\SalesRule\Model\Validator.php as

    Mage::dispatchEvent('salesrule_validator_process', array(
        'rule'    => $rule,
        'item'    => $item,
        'address' => $address,
        'quote'   => $quote,
        'qty'     => $qty,
        'result'  => $result,
    ));

Magento – Apply custom discount to admin order

Steps To Apply Custom Discount while placing order from admin:

Please follow the below steps:

Create sales.xml file in your custom module inside etc directory

<config xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="urn:magento:module:Magento_Sales:etc/sales.xsd">
    <section name="quote">
      <group name="totals">
        <item name="customdiscount" instance="[VendorName]\[Namespace]\Model\Quote\Address\Total\Discount" sort_order="500"/>
      </group>
   </section>
</config>

Create discount.php in [VendorName]/[Namespace]/Model/Quote/Address/Total

namespace [VendorName]\[Namespace]\Model\Quote\Address\Total;

use Magento\Catalog\Model\ProductRepository;

class Discount extends \Magento\Quote\Model\Quote\Address\Total\AbstractTotal
   {
      /** @var $_productRepository */ 
      protected $_productRepository;

    /**
      * Discount constructor.
      * @param ProductRepository $productRepository
      */
   public function __construct(
       ProductRepository $productRepository
   ) {
   $this->setCode('customdiscount');
   $this->_productRepository = $productRepository;
   }

 /**
   * Collect address discount amount
   * @param \Magento\Quote\Model\Quote $quote
   * @param \Magento\Quote\Api\Data\ShippingAssignmentInterface $shippingAssignment
   * @param \Magento\Quote\Model\Quote\Address\Total $total
   * @return $this
   */
public function collect(
\Magento\Quote\Model\Quote $quote,
\Magento\Quote\Api\Data\ShippingAssignmentInterface $shippingAssignment,
\Magento\Quote\Model\Quote\Address\Total $total
) {
$data = $quote->getItems();
if (!count($data)) {
    return $this;
}
parent::collect($quote, $shippingAssignment, $total);

/** Custom Discount is saved in line item level (i.e in quote_item) */
    foreach ($data as $item) {
         /** Add your Logic Here */
         if ($item['product_id'] == 'A' && $item['qty'] ) {
          $item->setDiscountAmount([setyourcustomdiscount]);
         $item->setBaseDiscountAmount([setyourcustomdiscount]);
         }

  }   
        /** Saving the values in quote_address table */
        $total->setDiscountDescription('Custom Discount');
        $total->setDiscountAmount([setTotalDiscountAmount]);
        $total->setBaseDiscountAmount([setTotalDiscountAmount]);

}
 Note : 1. setTotalDiscountAmount is the sum of all discount amount. 
        2. setyourcustomdiscount is the discount per item in cart id applicable. 
        3. sales.xml is used to add the custom discount. This is common for both frontend and admin.i.e this logic will work in frontend as well.

Best Answer

Related Solutions

Shopping Cart Price Rules – Apply Discount to One Item in Cart

Magento – Apply custom discount to admin order

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