public bool IsValidMyDetailsForm(ModelState modelState, MyDetailsViewModel myDetailsForm) { var firstNameField = nameof(myDetailsForm.FirstName); var lastNameField = nameof(myDetailsForm.LastName); var validationRules = new List <ValidationRuleItem <MyDetailsViewModel> >() { new ValidationRuleItem <MyDetailsViewModel> { Field = firstNameField, Rule = model => !string.IsNullOrEmpty(model.FirstName), ErrorMessage = "validation.required".AsWebSiteString() }, new ValidationRuleItem <MyDetailsViewModel> { Field = lastNameField, Rule = model => !string.IsNullOrEmpty(model.LastName), ErrorMessage = "validation.required".AsWebSiteString() }, }; return(myDetailsForm.IsValid(validationRules, modelState)); }