Grails - user - checkboxes and many-to-many

Grails - user - checkboxes and many-to-many

here's some snippets and comments below of some stuff I did with checkboxes for managing Roles for a User.
User and Role would be many-many except I am using a UserRole join class, with a method so I can get user.roles directly. So it's may not be exactly what you are looking for, but I hope it helps.