Add this code to your theme’s functions.php file:
In this post I will include my code to track, store and pass HasOffers (affiliate id + transaction id + amount of order) data from the the first page, through the order details and back to HasOffers when the purchase is successfull. I will divide the process to a few steps: Track the Transaction ID […]
Put it in your theme’s functions.php. Whenever your visiot will try to add a product twice mistakenly, it will keep only 1 of this product in his cart. However, he will be still able to change the quantity of the single product he has in cart.
Put it into your theme’s functions.php: