AngularJS Example
by vinodlouis
HTML
<div ng-app="">
<input type="button" value="set" ng-click="myVar='my-class'">
<input type="button" value="clear" ng-click="myVar=''">
<br>
<span ng-class="myVar">Sample Text</span>
</div>
CSS
</style> <!-- Ugly Hack due to jsFiddle issue: http://goo.gl/BUfGZ -->
<script src="http://ajax.googleapis.com/ajax/libs/angularjs/1.0.6/angular.min.js"></script>
<style>
.ng-invalid { border: 1px solid red; }
.my-class {
color: red;
}