Angular: Empty Fiddle

http://angularjs.org/

HTML

<script src="http://code.angularjs.org/angular-1.0.1.js"></script>
<div ng-controller="MyCtrl">
    <input ng-model="myText" ng-pattern="/^(0*[1-9]+0*)+$/" type="text" />
    {{inputValidity()}}
</div>

JavaScript

var myApp = angular.module('myApp',[]);

function MyCtrl($scope) {
    
    $scope.inputValidity = function() {
        if ($scope.myText === undefined || $scope.myText.length === 0) {
            return "Error! Bad input"
        }
        else {
            return "Success! Input was valid!"
        }        
    }
}