maproot/mapall options need to be greyed out if nfsv4 checked
From http://www.freebsd.org/cgi/man.cgi?exports%285%29, the maproot and mapall options do not apply to NFSv4. If one checks the box to enable NFSv4 in Services -> NFS, these options should be greyed out in the Add NFS Share screen.
It is probably worthwhile to have a pop-up message occur when checking NFSv4 to warn the user that these options don't apply, in case they already have shares using these options (or, if it only applies to new shares, it should indicate that as well).
#2 Updated by Dru Lavigne about 6 years ago
The second component of a line specifies how the file system is to be exported to the host set. The option flags specify whether the file system is exported read-only or read-write and how the client UID is mapped to user credentials on the server. For the NFSv4 tree root, the only option that can be specified in this section is -sec.