Complex discount requirements

Hi.

Just for 16, not >= 16?

I think this may require some customisation since it’s such a specific rule.

One approach, for the discount amounts, if there are many different % values you could probably put the % value in a custom field per product.

If there are only a handful of products, the logic could just go in the code and look at the product IDs themselves.

To run the code, I think the ‘woocommerce_get_discounted_price’ hook would be suitable. Thats ran per line and gets passed the line items.

As for the count, we have a helper called “get_cart_contents_count()” so that part is simple enough.

add_filter( 'woocommerce_get_discounted_price', 'custom_discounted_price_rules', 10, 2 );

function custom_discounted_price_rules( $price, $values ) {
	if ( 16 === WC()->cart->get_cart_contents_count() ) {
		$product_id = $values['product_id'];

		switch ( $product_id ) {
			case 901 : // For product ID 901
				$discount = '5'; // 5%
				break;
			default :
				$discount = 0;
				break;
		}

		if ( $discount ) {
			$price = $price - ( $price / 100 * $discount );
		}
	}
	return $price;
}

This would apply a 5% discount on ID 901 if cart count is 16. As for display, it won’t show anything special, just an adjusted total in the cart, so you’d probably want to show that the discount happened somewhere, maybe in the totals table or as a notice.

Just to clarify, you had 16 items in cart? Thats the quantities combined.

Try changing:

$product_id = $values['product_id'];

to

$product_id = absint( $values['product_id'] );

This will keep it numeric.

The code I posted above did work fine on my test install.