We have a booking system which should allow only one product in the cart (when customers adds next product, previous one should be deleted from the cart).
Until today we have been using following code:
add_filter( 'woocommerce_add_to_cart_validation', 'b_only_one_in_cart', 99, 2 );
function b_only_one_in_cart( $passed, $added_product_id ) {
wc_empty_cart();
return $passed;
}
But it ceased to work (and I can't find why). Has something changed in the recent version of WooCommerce? How can I get it to work again?