I wanted to implement a buy 3 free 1 feature, so I wrote a script that detect whether customer has 3 same items in cart and automatically add 1 more same item to the cart. Then using another hook, I overwrite the price of the product to 0.
I googled the solution and used the same approach found on:
- WooCommerce: Add product to cart with price override?
- woocommerce add custom price while add to cart
Here is the code sample:
foreach($cart_object->cart_contents as $k=>$item):
if(isset($item['variation']['promo']) && ($item['variation']['promo']) == 'buy 3 free 1'):
$item['data']->price = 0;
When Woocommerce calculate the subtotal for the cart, it always add in the original price of the product that is supposed to be free. For example, when I added 3 $100 item to cart, the cart subtotal ends up with $400 instead of $300.
I digged deeper into the Woocommerce code and found that in https://docs.woocommerce.com/wc-apidocs/source-class-WC_Cart.html#1139,
$item['data']->get_price() is used which always return the original price for the item.
Is there anyway to fix this using hooks/apis instead of editing Woocommerce core file?