During early stage development of the plugin that I use to create complex data structure combinations with custom post types, taxonomies, and meta data, I found several features that were either missing from the WordPress admin UI, or were difficult to easily achieve, and which would be better integrated as an argument to generic functions.
I logged these as TRAC requests on the WordPress.org site. It’s time for a revisit and update on how these have done, and if they have been integrated into WordPress core, in some shape or form, in a WordPress 4.x.x release. Firstly, all were accepted and have been worked on by the core dev team.
#23421: Add sortable to taxonomy column
Accepted Enhancement
It is possible to add a taxonomy column to the post type list for posts and custom posts types in the admin UI. However these are not immediately sortable columns. It’s possible to add this functionality through the use of a few filters, and some additional code / sql. This is a request to simplify this as an argument to the register_taxonomy function.
Ongoing
#23422: Add query filter argument to register_taxonomy
New Enhancement
It is possible to add a taxonomy column to the post type list for posts and custom posts types in the admin UI. It is also possible through the use of a few filters and custom code / sql to add a select dropdown filter to the post / post type listings which will filter the query results for the chosen taxonomy term. Multiple filters create a drill-down mechanism.
Ongoing
#33841: WP_Dropdown_Categories: Parent Category Optgroups
New Enhancement
On a number of occasions I’ve structured a hierarchical taxonomy with parent > child categories, but have only wanted to be able to select the child categories. An example of this is country > county, or manufacturer > model. It’s possible to create a custom Walker class to do this and override the default class. This enhancement request is to codify this as an argument to the wp_dropdown_categories function.
Ongoing
So, a success of sorts. The cogs of WordPress development move slowly. Hopefully the outstanding request will be added in due course. The new Taxonomy class may get them kick-started.