Look at how this is done for the "New Project" section. I have a "validate" class on the inputs in the HTML and some data attributes that know how to validate. This would cause the validation to occur on keyup instead of when you click Add.
The only thing you'd have to add to my validate code is how to disable the "Add" button when there is an error, since mine only accounts for dialog buttons.

Granted, Kristian is thinking about changing validation to use Angular anyway, but we should still be consistent until then.