I have a custom form that users make various selections before being presented with products they can buy. I need to add some logic that if an input has been selected when the user adds a product to the cart, it will also add an additional product to the cart.
The input is 3 radio check boxes. Somehow I need to hook into the add to cart click and check the page to see if one of the radios has been selected and then add the appropriate product but I'm not sure where to start.
I know I'll need to have an action that runs something like:
WC()->cart->add_to_cart( 'product_id', 'quantity');
But I'm not sure how to hook into the initial add to cart click and how to check for the radios on the page.
Thank you for your help.