Add a custom per-user setting in a plugin

[JQ331]

This is a very helpful post laying out a straight forward example of setting up a user custom field. Is there anything similar for helping guide through a simple topic custom field? I am trying to work through it here:

How to add a super basic topic custom field

I’m trying to understand how to add a custom field to topics, and working through a very basic example. Goal: Add a custom field called “sample_field” to each topic created, with a simple string value. I’ve reviewed various examples, like the poll plugin and the solved plugin and this discussion, but these plugins do so much more with their custom fields that I haven’t yet figured out the basic code you need. So I’m not quite there–my plugin.rb file is missing something (I think), and I haven’…

But I haven’t gotten it to work quite yet. I would really appreciate any help on it.