I am looking for a way for users (who will be site admins) to design Blocks that will be used by a plugin I am developing. I want the solution to work in both Classic and Block themes, so I have been exploring the support for Template Part Blocks in Classic themes.
This is working, and when I go to Appearance / Template Parts, the existing Template Parts I have defined can be edited. However there is no option to add a new Template Part. It appears that the only way to add one is to put a .html file into the file system. Note that at present I am adding these files to my Theme folder, but I have found a solution that will allow them to be added to my Plugin folder, I just haven't implemented this yet.
Is there a way to allow users to create new Template Parts in Classic Themes without creating a file manually?
I have considered providing an option on one of my admin screens to create a new file for the Template Part, which the user could then update with the editor, but I am concerned that these files would be lost when the plugin is updated.