SecuredActivity.js

    public class SecuredActivity : CodeActivity
    {
        [RequiredArgument]
        public string Roles { get; set; }

        protected override void Execute(CodeActivityContext context)
        {
            EnforceSecurity();
        }

        void EnforceSecurity()
        {
            var ok = new Func<bool>(() =>
            {
                var roles = Roles.Split(new[] { ',', ';' }, StringSplitOptions.RemoveEmptyEntries).ToList();
                var orgName = AppContext.Current.OrganisationName;
                return roles.Any(r =>
                {
                    var role = string.Format("{0}:{1}", orgName, r);
                    return AppContext.Current.User.IsInRole(role);
                });
            });

            if (!AppContext.HasContext || !ok())
            {
                throw new UnauthorizedAccessException();
            }
        }
    }