using FluentValidation; namespace BlazorEditForms.Model; public class Aggregate { public Aggregate(Employee employee, User? user) { Employee = employee; User = user; } public Employee Employee { get; set; } public User? User { get; set; } } public class AggregateValidator : AbstractValidator { public AggregateValidator() { RuleFor(x => x.Employee).NotNull().SetValidator(new EmployeeValidator()); When(x => x.User != null, () => RuleFor(x => x.User!).SetValidator(new UserValidator())); } }