Allow customers to add arbitrary data to products when adding to cart

Question

I've got a product type called workshop and I want customers to be able to specify the names of their kids when they add a workshop to the cart. If I could figure out how to add any arbitrary data at all I'm sure I could carry this through to where I ultimately want it to be, which is that the arbitrary data would actually be a choice of some number of Paragraph entities referenced by their user profile, but all the solutions I have been able to find seem to be for Drupal 7, so I'm dead in the water.

Any suggestions?

Answer 1

For the benefit of anyone who comes looking, the answer is that the fields need to be added to the order item type. Commerce sees each product as a sort of Platonic object and stamps out instances as order items -- think line items. You can add fields to this. Whee. Unfortunately, you can't reference Paragraph entities because, as ridiculous as it seems to me, Paragraph entities only support a single reference.