Still in alpha, and still a bit proof of concept, I released today a new version that supports ASP.NET MVC (Preview 4). Client side validation is handled by jquery.validation (http://docs.jquery.com/Plugins/Validation).

Currently, only required and email validators are implemented. Type validation is done server side. I will continue to add features during the week. Now, let's validate some users!

Still simple to use, all you have to do is :

Download the project on codeplex : http://www.codeplex.com/SimpleValidation

Create your entity (nothing new here!)

public class User
{
    private string name;
    private int age;
    private string email;
    private string password;
    private decimal size;

    [Required("Name is required")]
    public string Name
    {
        get { return this.name; }
        set { this.name = value; }
    }

    [Required("Age is required")]
    [Range(0, 99, "Age must be in range {0} {1}")]
    [ValidateType("Age format is not valid")]
    public int Age
    {
        get { return this.age; }
        set { this.age = value; }
    }

    [ValidateType("Size format is not valid")]
    public decimal Size
    {
        get { return this.size; }
        set { this.size = value; }
    }

    [Email("Email is invalid")]
    [Confirm("Please confirm your email")]
    [Required("Email is required")]
    public string Email
    {
        get { return this.email; }
        set { this.email = value; }
    }

    [Confirm("Please confirm your password")]
    [Required("Password is required")]
    public string Password
    {
        get { return this.password; }
        set { this.password = value; }
    }
}

This one is self explanatory

Create your view

<%=Html.CreateValidators<Samples.Entities.User>("signupForm")%>

<%using( Html.Form("User", "New", FormMethod.Post, new Dictionary<string, object>() { { "id", "signupForm"} } ) ) { %>
    <div class="inputform">
        <fieldset>
            <legend>
                User
            </legend>
            <label>Name:</label>
            <div class="droite">
                <%= Html.TextBox("Name", ViewData["Name"] as string) %>
                <%= Html.ValidationErrors("Name") %>
            </div>
            
            <label>Password:</label>
            <div class="droite">
                <%= Html.TextBox("Password")%>
                <%= Html.ValidationErrors("Password")%>
            </div>
            
            <label>Confirm Password:</label>
            <div class="droite">
                <%= Html.TextBox("PasswordConfirm")%>
                <%= Html.ValidationErrors("PasswordConfirm")%>
            </div>

            <label>Age:</label>
            <div class="droite">
                <%= Html.TextBox("Age", ViewData["Age"] as string)%>
                <%= Html.ValidationErrors("Age")%>
            </div>
            
            <label>Size:</label>
            <div class="droite">
                <%= Html.TextBox("Size", ViewData["Size"] as string)%>
                <%= Html.ValidationErrors("Size")%>
            </div>

            <label>Email:</label>
            <div class="droite">
                <%= Html.TextBox("Email", ViewData["Email"] as string)%>
                <%= Html.ValidationErrors("Email")%>
            </div>

            <label>Confirm Email:</label>
            <div class="droite">
                <%= Html.TextBox("EmailConfirm", ViewData["EmailConfirm"] as string)%>
                <%= Html.ValidationErrors("EmailConfirm")%>
            </div>
            
            <div class="droite boutons">
                <input type="submit" value="Register" />
            </div>
        </fieldset>

    </div>
<%} %>

Don't forget to add a reference to jquery (http://jquery.com/) and jquery.validation (http://docs.jquery.com/Plugins/Validation)

Create your controller

public class UserController : Controller
{
    public ActionResult Index()
    {
        return View("New");
    }

    public ActionResult New()
    {
        User u = new User();

        if (!MvcValidationHelper.UpdateFrom(u, Request.Form, ViewData))
        {
            return View();
        }

        return View("UserCreated", u);
    }
}

And there you go !