I want to add styles to
editor-style.css, based on the category the current post belongs to.
Therefore I would like to add the post classes - using
get_post_class() - to the body of the TinyMCE iframe.
get_post_class(). Neither can I use the
admin_body_class filter, because that doesn't address the TinyMCE iframe.
How can I add the post's classes to the TinyMCE iframe?