ASP.NET MVC3: ValidationType ModelClientValidationRule

Question

I just created a sample MVC3 application to study validation. It uses DataAnnotations. I created a custom ValidationAttribute named CustomStartLetterMatch. It implements "System.Web.Mvc.IClientValidatable". I have the appropriate client-side code written with unobtrusive jQuery. This works as expected.

About the user validator: it compares the input of the name and the name of the first name. It throws an error if the first character of both of them is not the same.

As I said, the application works fine. But when I looked at rule.ValidationType = "greaterdate";, I was embarrassed. I wanted to change it to something like "anotherDefaultType". When I change it, it fails with jQuery error.

• What is the reason for this?
• What are the valid ValidationType templates?
• What is the suggested approach for changing ValidationType in this scenario.

CODE:

using System;
using System.ComponentModel.DataAnnotations;
using System.Collections.Generic;
namespace MyValidationTEST
{
    public class Person
    {
    [Required(ErrorMessage = "First name required")]
    public string FirstName { get; set; }

    [CustomStartLetterMatch("FirstName")]
    [StringLength(5,ErrorMessage = "Must be under 5 characters")]
    public string LastName { get; set; }

    [Range(18,50,ErrorMessage="Must be between 18 and 50")]
    public int Age { get; set; }

}



public sealed class CustomStartLetterMatch : ValidationAttribute, System.Web.Mvc.IClientValidatable 
{

    private const string _defaultErrorMessage = " First letter of '{0}' must be same as first letetr of '{1}'";
    private string _basePropertyName;

    public CustomStartLetterMatch(string basePropertyName)
        : base(_defaultErrorMessage)
    {
        _basePropertyName = basePropertyName;
    }


    //Override FormatErrorMessage Method
    public override string FormatErrorMessage(string name)
    {
        return string.Format(_defaultErrorMessage, name, _basePropertyName);
    }


    //Override IsValid
    protected override ValidationResult IsValid(object value, System.ComponentModel.DataAnnotations.ValidationContext validationContext)
    {
        //Get PropertyInfo Object
        var basePropertyInfo = validationContext.ObjectType.GetProperty(_basePropertyName);
        var baseValue = (string)basePropertyInfo.GetValue(validationContext.ObjectInstance, null);
        var currentValue = (string)value;


        string firstLetterBaseValue = baseValue.Substring(0, 1);
        string firstLetterCurrentValue = currentValue.Substring(0, 1);

        //Comparision
        if (!string.Equals(firstLetterBaseValue, firstLetterCurrentValue))
        {
            var message = FormatErrorMessage(validationContext.DisplayName);
            return new ValidationResult(message);
        }

        //Default return - This means there were no validation error
        return null;
    }


    public IEnumerable<System.Web.Mvc.ModelClientValidationRule> GetClientValidationRules(System.Web.Mvc.ModelMetadata metadata, System.Web.Mvc.ControllerContext context)
    {
        var rule = new System.Web.Mvc.ModelClientValidationRule();
        rule.ErrorMessage = FormatErrorMessage(metadata.GetDisplayName());
        rule.ValidationParameters.Add("other", _basePropertyName);
        rule.ValidationType = "greaterdate";
        yield return rule;
    }



}

}

VIEW

@model MyValidationTEST.Person

@{
ViewBag.Title = "Create";
}

<h2>Create</h2>

<script src="@Url.Content("~/Scripts/jquery-1.5.1.min.js")" type="text/javascript">  </script>

@*UnObtrusive*@
<script src="@Url.Content("~/Scripts/jquery.validate.min.js")" type="text/javascript"></script>
<script src="@Url.Content("~/Scripts/jquery.validate.unobtrusive.min.js")" type="text/javascript"></script>



<script type="text/javascript">

/*Register adapter - addSingleVal*/
jQuery.validator.unobtrusive.adapters.addSingleVal("greaterdate", "other");


/*Validation type names in unobtrusive client validation rules must consist of only lowercase letters*/

/*Add Method*/
jQuery.validator.addMethod("greaterdate",
                                    function (val, element, other) 
                                    {

                                        var modelPrefix = element.name.substr(0, element.name.lastIndexOf(".") + 1)
                                        var otherVal = $("[name=" + modelPrefix + other + "]").val();

                                        if (val && otherVal) 
                                        {
                                            var lastNameFirstLetter = val.substr(0, 1);
                                            var firstNameFirstLetter = otherVal.substr(0, 1);

                                            if (lastNameFirstLetter != firstNameFirstLetter) 
                                            {
                                                return false;
                                            }
                                        }
                                        return true;
                                    });


</script>


@using (Html.BeginForm()) {
@Html.ValidationSummary(true)
<fieldset>
    <legend>Person</legend>

    <div class="editor-label">
        @Html.LabelFor(model => model.FirstName)
    </div>
    <div class="editor-field">
        @Html.EditorFor(model => model.FirstName)
        @Html.ValidationMessageFor(model => model.FirstName)
    </div>

    <div class="editor-label">
        @Html.LabelFor(model => model.LastName)
    </div>
    <div class="editor-field">
        @Html.EditorFor(model => model.LastName)
        @Html.ValidationMessageFor(model => model.LastName)
    </div>

    <div class="editor-label">
        @Html.LabelFor(model => model.Age)
    </div>
    <div class="editor-field">
        @Html.EditorFor(model => model.Age)
        @Html.ValidationMessageFor(model => model.Age)
    </div>

    <p>
        <input type="submit" value="Create" />
    </p>
</fieldset>
}

<div>
@Html.ActionLink("Back to List", "Index")
</div>

CONTROLLER:

using System.Web.Mvc;
namespace MyValidationTEST.Controllers
{
public class RelativesController : Controller
{

    // GET: /Relatives/
    public ActionResult Index()
    {
        return View();
    }



    // GET: /Relatives/Create
    public ActionResult Create()
    {
        Person person = new Person();
        return View(person);
    }


    // POST: /Relatives/Create
    [HttpPost]
    public ActionResult Create(Person relativeToAdd)
    {
        if (ModelState.IsValid)
        {
            return RedirectToAction("Index");
        }
        return View(relativeToAdd);
    }

    }

 }

READING:

ASP.NET MVC3 - Custom Validation Attribute -> Client Side Does Not Work

Answer 1

I wanted to change it to something like "anotherDefaultType"

You can use only lowercase letters for the ValidationType property:

rule.ValidationType = "anotherdefaulttype";

and then adapt your client script to reflect this modification:

jQuery.validator.unobtrusive.adapters.addSingleVal("anotherdefaulttype", "other");
jQuery.validator.addMethod("anotherdefaulttype", function (val, element, other) {
    ...
});