How do I update the unit price of an order item on Add to Cart in Commerce 2.x?

Question

I added an event subscriber for add to cart event. There I defined a function to react on add to cart event. Everything works fine as my eventsubscriber is being called. I want to update the unit price of product which is being added to cart. Below is the code I used but it is not working. Price of the product is not updating to the price I am setting.

public function updateProductPrice(CartEntityAddEvent $event) {
    $unit_price = new Price('15.00', 'EUR');
    $event->getOrderItem()->setUnitPrice($unit_price,TRUE);    
  }

I have tried with both overide TRUE and FALSE but nothing works.

Answer 1

The problem with this approach is the price will be recalculated on the next order item refresh. You can't just depend on altering this item at the Add to Cart. You'll need a price resolver or else some other tie into the order refresh process.

Answer 2

I managed to update the price by updating the order item of order rather than the order item in event.

$items = $event->getOrder()->getItems();
foreach ($items as $key => $item) {
    $currencyCode = $item->getUnitPrice()->getCurrencyCode();
    $unit_price = new Price('20.00', $currencyCode);
    $item->setUnitPrice($unit_price,TRUE);
    $item->save();
}