I'm building a site for a printing company that allows people to upload a document, specify lots of parameters and then order a print of that document. I'm using Woocommerce (to have a generic and extendable order/payment system) and GForms Product Add-ons (to create a big form as part of the ordering process).
In the general GForm-documentation I'm told to ALSO include any custom calculations in PHP-code in the gform_product_info-filter. However, when using GForms in the Product Add-ons extension, this filter doesn't seem to have any effect at all, any information I update in there is completely ignored. Also, the price is a string there, which doesn't look like it's used for any more calculations. All examples I can find are about adding extra sections like taxes or shipping, but not about modifying the actual product price. And, in the Product Add-ons setup, even adding a section doesn't seem to work.
So, the basic question: How can I use my own program code to manipulate the product price that is sent by the Product Add-ons extension to the shopping cart?
Thanks for any help!