MenuWidget provides a hierachical GTK menu containing all applicable desktop entries found on the system. The menu is built according to the version 1.1 of the XDG "Desktop Menu Specification", see https://specifications.freedesktop.org/menu-spec/menu-spec-1.1.html

In order to use this widget add the following line to your taffybar.hs file:

import System.Taffybar.Widget.XDGMenu.MenuWidget
main = do
  let menu = menuWidgetNew $ Just "PREFIX-"

The menu will look for a file named "PREFIX-applications.menu" in the (subdirectory "menus" of the) directories specified by the environment variable XDG_CONFIG_DIRS and "etcxdg". If no prefix is given (i.e. if you pass Nothing) then the value of the environment variable XDG_MENU_PREFIX is used, if it is set. If taffybar is running inside a desktop environment like Mate, Gnome, XFCE etc. the environment variables XDG_CONFIG_DIRS and XDG_MENU_PREFIX should be set and you may create the menu like this:

  let menu = menuWidgetNew Nothing

Now you can use menu as any other Taffybar widget.