MVC unobtrusive validation on checkbox not working

asp.net-mvc-3razorunobtrusive-javascriptunobtrusive-validation

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 hasn't selected the checkbox, then the input should be marked as invalid.

This is the server side Validator code, I've added:

/// <summary>
/// Validation attribute that demands that a boolean value must be true.
/// </summary>
[AttributeUsage(AttributeTargets.Property, AllowMultiple = false, Inherited = false)]
public class MustBeTrueAttribute : ValidationAttribute
{
    public override bool IsValid(object value)
    {
        return value != null && value is bool && (bool)value;
    }
}

This is the model

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

This is my view:

@Html.EditorFor(x => x.AcceptTermsAndConditions)
@Html.LabelFor(x => x.AcceptTermsAndConditions)
@Html.ValidationMessageFor(x => x.AcceptTermsAndConditions)

and this is the jQuery I've used to attach the validator client side:

$.validator.unobtrusive.adapters.addBool("mustbetrue", "required");

The client side script doesn't appear to be kicking in, however. Whenever I press the submit button, validation on the other fields kicks in fine, but the validation for the Terms & conditions doesn't seem to kick in. This is how the code looks in Firebug after I've clicked the submit button.

<input type="checkbox" value="true" name="AcceptTermsAndConditions" id="AcceptTermsAndConditions" data-val-required="The I confirm that I am authorised to join this website and I accept the terms and conditions field is required." data-val="true" class="check-box">
<input type="hidden" value="false" name="AcceptTermsAndConditions">
<label for="AcceptTermsAndConditions">I confirm that I am authorised to join this website and I accept the terms and conditions</label>
<span data-valmsg-replace="true" data-valmsg-for="AcceptTermsAndConditions" class="field-validation-valid"></span>

Any ideas? Have I missed out a step? This is driving me potty!

Thanks in advance
S

Best Answer

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<ModelClientValidationRule> 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

<script src="@Url.Content("~/Scripts/jquery.validate.js")" type="text/javascript"></script>
<script src="@Url.Content("~/Scripts/jquery.validate.unobtrusive.js")" type="text/javascript"></script>
<script type="text/javascript">
    $.validator.unobtrusive.adapters.addBool("mustbetrue", "required");
</script>

@using (Html.BeginForm())
{
    @Html.CheckBoxFor(x => x.AcceptsTerms)
    @Html.LabelFor(x => x.AcceptsTerms)
    @Html.ValidationMessageFor(x => x.AcceptsTerms)
    <input type="submit" value="OK" />
}

Related Solutions

C# – File Upload ASP.NET MVC 3.0

You don't use a file input control. Server side controls are not used in ASP.NET MVC. Checkout the following blog post which illustrates how to achieve this in ASP.NET MVC.

So you would start by creating an HTML form which would contain a file input:

@using (Html.BeginForm("Index", "Home", FormMethod.Post, new { enctype = "multipart/form-data" }))
{
    <input type="file" name="file" />
    <input type="submit" value="OK" />
}

and then you would have a controller to handle the upload:

public class HomeController : Controller
{
    // This action renders the form
    public ActionResult Index()
    {
        return View();
    }

    // This action handles the form POST and the upload
    [HttpPost]
    public ActionResult Index(HttpPostedFileBase file)
    {
        // Verify that the user selected a file
        if (file != null && file.ContentLength > 0) 
        {
            // extract only the filename
            var fileName = Path.GetFileName(file.FileName);
            // store the file inside ~/App_Data/uploads folder
            var path = Path.Combine(Server.MapPath("~/App_Data/uploads"), fileName);
            file.SaveAs(path);
        }
        // redirect back to the index action to show the form once again
        return RedirectToAction("Index");        
    }
}

Javascript – Disable required validation by JavaScript

I've handled cases like this with a custom Validation Attribute. Instead of using the Required attribute for properties you could make a RequiredIf attribute and make some of your properties required only if another property is a certain value.

Here is a post about creating an attribute like this (the example in the middle of the page under the 'A more complex custom validator' section): http://www.devtrends.co.uk/blog/the-complete-guide-to-validation-in-asp.net-mvc-3-part-2

If your checkbox represents a property in your model this should work fine.

If you don't want to handle this with a new validation attribute you will have to do a few more things than just change the data-val attribute to false. When jQuery validate first parses your form it stores values in the form's data. So simply changing data-val isn't enough. You will additionally have to remove the stored validation data and reparse the form. Here's an example:

// Do this after you've removed/modified the data-val attribute
$('selector for your form').removeData('unobtrusiveValidation');
$('selector for your form').removeData('validator');
$.validator.unobtrusive.parse('selector for your form');

Best Answer

Related Solutions

C# – File Upload ASP.NET MVC 3.0

Javascript – Disable required validation by JavaScript

Related Topic