dongtac wrote:I'm trying to make a custom device action in device manager for a script to format removable media storage devices.

Well, there's the "quick usb formatter" ( https://gitorious.org/chakra/quick-usb-formatter ) that seems to do what you want.
It's still KDE4 based though, so the solid action won't show up in Plasma5 unless you copy or symlink the files to the proper location (/usr/share/solid/).

Anyway, its solid action file contains this predicate:

Code: Select all

[Desktop Entry]
Actions=open;
Type=Service
X-KDE-Action-Custom=true
X-KDE-Solid-Predicate=IS StorageAccess


So that ("IS StorageAccess") should work for you too, I suppose...

Note that you have to logout/login for the new rule to work, IIRC.