Question

My code is here: http://plnkr.co/edit/2WDK0b

Is it possible that when I enter an existing username, the message in the “help-block” span will change dynamically?

Answer 1

Just wrap your existing checking code in a function in the controller. Like $scope.checkUsername = function() { //your existing code }

Now on your username input put ng-change="checkUsername()" and then it will work.

Before you get too much further make sure to read the validation bits from the Angular Form’s guide: http://docs.angularjs.org/guide/forms

Here’s a fiddle of your code working: http://plnkr.co/edit/LwMJGq?p=preview Although I think the logic for the name checking needs a bit of work.