How to make a select form element with textfields for the array id and key?

Question

In a custom module which I'm working on, I have a select list which currently has a hard-coded array of key=>value which could change and I would like to expose these options to the user.

I would like to be able to have a select form element which contains one textfield for the user to enter the ID of the option and another for the user to enter the value of the option. I could make a separate form for these options, but I'd like to keep all the configurations on one page since there aren't too many.

Does anyone know how I can make a select form element where the key and value of each option is keyed in by the user?

Answer 1

Do you know of Drupal's core field type "List" or what it's called and its "Allowed Values" field? Where admins can enter key|value pairs divided by a pipe character?

It's exactly what you seem to describe.

I'd start by mimicking exactly that. But all in one form. Maybe multi-step. Maybe peppered with some Ajax...