MVC unobtrusive validation on checkbox not working

Question

I\'m trying to implement the code as mentioned in this post. In other words I\'m trying to implement unobtrusive validation on a terms and conditions checkbox. If the user

Answer 1

You need to implement IClientValidatable on your custom attribute in order to tie the mustbetrue adapter name that you are registering on the client side with this attribute:

[AttributeUsage(AttributeTargets.Property, AllowMultiple = false, Inherited = false)]
public class MustBeTrueAttribute : ValidationAttribute, IClientValidatable
{
    public override bool IsValid(object value)
    {
        return value != null && value is bool && (bool)value;
    }

    public IEnumerable GetClientValidationRules(ModelMetadata metadata, ControllerContext context)
    {
        yield return new ModelClientValidationRule
        {
            ErrorMessage = this.ErrorMessage,
            ValidationType = "mustbetrue"
        };
    }
}

---

UPDATE:

Full working example.

Model:

public class MyViewModel
{
    [MustBeTrue(ErrorMessage = "You must accept the terms and conditions")]
    [DisplayName("Accept terms and conditions")]
    public bool AcceptsTerms { get; set; }
}

Controller:

public class HomeController : Controller
{
    public ActionResult Index()
    {
        var model = new MyViewModel();
        return View(model);
    }

    [HttpPost]
    public ActionResult Index(MyViewModel model)
    {
        return View(model);
    }
}

View:

@model MyViewModel





@using (Html.BeginForm())
{
    @Html.CheckBoxFor(x => x.AcceptsTerms)
    @Html.LabelFor(x => x.AcceptsTerms)
    @Html.ValidationMessageFor(x => x.AcceptsTerms)
    
}