We could change it from being a hidden field to a text field and the same code would work as expected, but that’s not what we want to do.As it turns out, they made it rather simple to extend the built-in validation with your own custom rules.First, we’ll define the attribute class, so that it can be added as a decorator to a property the same way the other validators work.

validating net-45validating net-20validating net-77

As soon as there are validation errors, the screen changes from popup to normal window.

Is there a way to show the errors in modal-popup only.

One of the many nice things they have added in MVC 2 is model/view model validation on both the client and server side.

If that end value is something that is required, it’s only natural that that should be enforced by the model.

First, let’s start by defining a very simple view model for the form: If you run the page now, you will get correct server-side validation, but nothing on the client.

To get client validation in MVC, we need to tell the page to enable client validation.

To do that, call this before starting the form: Now if you reload the page, client validation still isn’t working. After digging through the Microsoft validation scripts a bit, I found that the Required validator ignores hidden fields altogether in Java Script.

I won’t go into the basics here since they have been covered extensively by others.

However, recently I was adding validation to require a value for a hidden field on a form, and found that the default validation functionality just didn’t work on the client side for a hidden field.

Here I will go over how I added some custom validation to allow me to do it.

While it might sound weird to validate a hidden field, something a user will never directly interact with, in this age of complex interfaces built in Java Script it’s easy to imagine a scenario where a series of interactions leads to storing some kind of value in a hidden field.