I'm working on a site update for a client. The current version of their site stores a lot of information within custom post meta fields, added as plain text boxes using Advanced Custom Fields. We think this information would serve the site better if it existed as a taxonomy, so we'd like to move all this information into a custom taxonomy.
This is a film site and one example is that the film's director is stored as a plain text post meta field. If it were part of a Director taxonomy instead, we could easily look at all films tagged with that Director.
So my question - is there is an easy way to move or copy information in a post meta field to a custom taxonomy? My plan at the moment is to look at a plugin for copying info between taxonomies and seeing if I can modify that. But if anyone knows of another solution, I'd be grateful!