Your example works for conditioned classes (the class name will show if the expressionDataX
is true):
<div ng-class="{class1: expressionData1, class2: expressionData2}"></div>
You can also add multiple classes, supplied by the user of the element:
<div ng-class="[class1, class2]"></div>
Usage:
<div class="foo bar" class1="foo" class2="bar"></div>