Question

is there any way to validate using ModelState and model, to determine the type of error?

example:

[Required]

I wanted to make a custom ValidationMessageFor, and within it whether the error is [Required] or other type of error.

I am using DataAnnotations and CodeFirst.

Have is code from start implemetantion:

public static MvcHtmlString MyValidationMessageFor<TModel, TProperty>(this HtmlHelper<TModel> helper, Expression<Func<TModel, TProperty>> expression)
{
    var Validacao = "";       
    if (helper.ViewData.ModelState[((MemberExpression)expression.Body).Member.Name] != null)
    {   
        foreach (var erros in helper.ViewData.ModelState[((MemberExpression)expression.Body).Member.Name].Errors)
        {
            Validacao = Validacao + " *";
        }
    }            
    return MvcHtmlString.Create(Validacao);
}

tks

Answer 1

Any validation attribute has ErrorMessage property you can use to specify error message directly in attribute. Example:

[Required(ErrorMessage = "required error")]
[MaxLength(10, ErrorMessage = "max length error")]