I'm trying to make use of the new Media taxonomy functionality to create a more robust media library. I've hit a bit of a brick wall with actually assigning uploaded media items to categories. I've set up the custom taxonomy and called it Media Categories (wcmedia), and it is working just fine, but the issue is that the media modal on the posts screen (Add Media) is not recognising the fact I've selected hierarchical. The hierarchical display seems to work fine on the actual edit media page, but it's on actual upload where it would be most useful (otherwise users need to upload and then navigate away to the actual edit media page and assign the category from there).
There seems to a couple of robust plugins that offer this sort of fucntionality, but I'm keen to avoid using a full-scale plugin what I'm hoping is just a few line fix. I don't even know why the default functionality of hierarchical category isn't honoured on the Add Media modal by default? Perhaps it is and I'm just missing something?
I think I have tracked down the function where the Add Media modal is pulling in the box for the Media Categories (
get_compat_media_markup), but I'm not sure if/how to hook into it to alter the output.
I've included a screenshot to illustrate the issue more clearly.