Steve Maine has a post about implementing validation in .NET using attributes. I agree that adding validation declaratively is a positive thing. I also think he hits the nail on the head when he mentions that not everything should be done via attributes. There are still many times when diving into writing some validation in you business/validation components makes the most sense. As with anything finding the right balance between the two is key. Rather then trying to do everything with a given technology it’s important that we find the just the right mix.
Below you can find some of m previous entries on the topic: