Angular: Empty Fiddle

http://angularjs.org/

HTML

<script src="http://code.angularjs.org/angular-1.0.1.js"></script>
<div ng-controller="MyCtrl">
    <div my-dir="{{direct}}">   
        <p>Test</p>
    </div>
</div>

JavaScript

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

function MyCtrl($scope) {
    $scope.direct = "rtl";
}

myApp.directive("myDir", function() {
    return {
        link: function(scope, elem, attrs) {
            attrs.$observe("myDir", function(newval) {
                if( newval ) {
                    elem.attr("dir", newval);
                }
                else {
                    elem.removeAttr("dir");
                }
            });
        }
    };
});