MVC 2 Beta - Validate two properties match

Is there any way of using the built-in validation attributes to validate this model:

public class TestModel
{
    public string Password {get;set;}
    [MustMatch("Password")]
    public string ConfirmPassword {get;set;}
}

Where MustMatchAttribute is a custom ValidationAttribute I've created. It would seem that with the default DataAnnotations classes there isn't?

Re: MVC 2 Beta - Validate two properties match

DataAnnotations 3.5 SP1 doesn't support what you're trying to do if the attribute is declared at the property level. However, since you have MVC 2 Beta, take a look at the RegisterModel type (in Models/AccountModels.cs in the default template). It shows an example of using something like [MustMatch], but declared on the model itself rather than on a property.

Re: MVC 2 Beta - Validate two properties match

Well that's good enough for me

Thanks a lot for your help

Re: MVC 2 Beta - Validate two properties match

Beware that there is small bug in that attribute implementation. Even tho it advertises that it can be used multiple times (AllowMultiple = true), this wont work. Thats because validation attributes discovery depends on TypeDescriptor and for it to see multiple instances of the same attribute TypeId property should be overriden like this:

public override object TypeId {
	get {
		return this;
	}
}

So if you want to require users to confirm both email and password, you will need to add this override.

Maciej

Re: MVC 2 Beta - Validate two properties match

Molesinski - thanks for the report. I've filed a bug on this.

Re: MVC 2 Beta - Validate two properties match

Still nothing something like requested ?

I'm using VS 2010 and C#.

I'm trying to do this on model and client side... Will be great if there is possibility to do it in "one place". The "MustMatch" attribute is exactly what I need.

Re: MVC 2 Beta - Validate two properties match

The account models include an example of this (server-side only) when you create a new MVC 2 project.

Writing a client-side version should be relatively simple.

Re: MVC 2 Beta - Validate two properties match

Hmmm.....

There is no something like this :| I've just checked...

1. Models are 'empty'

2. Validation of password and confirmPassword is ONLY in AccountControler in ValidateRegistration function. Nothing based on the properties... etc...

Re: MVC 2 Beta - Validate two properties match

We added this to MVC 2 Beta, but I see that you're using VS 2010, so you still have the older code (since VS 2010 Beta 2 shipped with MVC 2 Preview 2).

This is the attribute:

[AttributeUsage(AttributeTargets.Class, AllowMultiple = true, Inherited = true)]
public sealed class PropertiesMustMatchAttribute : ValidationAttribute
{
    private const string _defaultErrorMessage = "'{0}' and '{1}' do not match.";


    private readonly object _typeId = new object();


    public PropertiesMustMatchAttribute(string originalProperty, string confirmProperty)
        : base(_defaultErrorMessage)
    {
        OriginalProperty = originalProperty;
        ConfirmProperty = confirmProperty;
    }


    public string ConfirmProperty
    {
        get;
        private set;
    }


    public string OriginalProperty
    {
        get;
        private set;
    }


    public override object TypeId
    {
        get
        {
            return _typeId;
        }
    }


    public override string FormatErrorMessage(string name)
    {
        return String.Format(CultureInfo.CurrentUICulture, ErrorMessageString,
            OriginalProperty, ConfirmProperty);
    }


    public override bool IsValid(object value)
    {
        PropertyDescriptorCollection properties = TypeDescriptor.GetProperties(value);
        object originalValue = properties.Find(OriginalProperty, true /* ignoreCase */).GetValue(value);
        object confirmValue = properties.Find(ConfirmProperty, true /* ignoreCase */).GetValue(value);
        return Object.Equals(originalValue, confirmValue);
    }
}

Re: MVC 2 Beta - Validate two properties match

Thanks, anyway is there any way to have beta 2 in VS 2010 ? Normal install of Beta 2 from http://www.microsoft.com/downloads/details.aspx?FamilyID=4817cdb2-88ea-4af4-a455-f06b4c90fd2c&displaylang=en will work ?

Re: MVC 2 Beta - Validate two properties match

Nope. VS 2010 Beta 2 is stuck with MVC 2 Preview 2.

Re: MVC 2 Beta - Validate two properties match

See Phils Blog ASP.NET MVC 2 and Visual Studio 2010

ASP.NET MVC 2 RC is not supported on machines with Visual Studio 2010 Beta 2, Im really referring to the tooling.

The ASP.NET MVC 2 RC runtime is fully supported with the ASP.NET 4 runtime

Re: MVC 2 Beta - Validate two properties match

Just be aware that you will potentially might VS 2010 if you install a later version of MVC 2. Compatible with the runtime != compatible with Visual Studio. :)