to prevent only white spase in input

Hi!
I can't find solution how to to prevent only white space in input
I found:

.Field(
                        new Field("groupes.grp_nom")
                        .Validator(DataTables.Validation.Required(new ValidationOpts
                        {
                            Empty = false,
                            Message = "Champs obligatoires"

                        })))

But it accept ONLY white space.
Thanks in advance