I'm wondering how to add a custom field value to a custom post type's permalink? For example, I have the custom post file ex: cpt-cities.php, which handles registering the custom post type and all of those specifics.
Within that file, I'm trying to set it's permalinks to include one of the 'cities' custom field values. I'm able to set the permalinks using add_permastruct. However I'm not able to get the value of the custom field, and get_post_meta() does not work. This may be due to $post->ID not working (since it's within the custom post type file, and not a post loop).
Anyone know of a way to get the custom field value within a file like this? Is there somewhere else I can declare the add_permastruct, that will allow me to pull in the custom field value?
Any help is greatly appreciated, this is one of the last parts of a pretty extensive project.