Model-level validation

Question

How does one accomplish "model-level" validation as stated in Brad Wilson's post:

Finally, if you want a validation to have access to multiple properties, then make it a model-level validation (so that it gets the entire model as the model parameter, rather than a single individual property value).

From http://forums.asp.net/p/1457591/3650720.aspx

I tried to do the following

[MyCustomValidation("SomeStuff")]
public class MyClass
{
     // properties
}

Breakpoints place in the IsValid override of MyCustomValidation trigger nothing, the code just continues. Breakpoints in the constructor of MyCustomValidation work, but nothing after that.

Is this not what model-level validation refers to?

UPDATE:

dirtygopher's link to http://bradwilson.typepad.com/blog/2010/01/input-validation-vs-model-validation-in-aspnet-mvc.html shows model validation, the only issue is that the validation attributes are placed on the child properties of the parent class.

I'm looking for a way to place validation-attributes directly to the class as I demonstrated in my above example.

Answer 1

There's a good example for this in the RegisterModel that comes with the latest asp.net mv 2.

Look at the "PropertiesMustMatch" attribute and its usage.