Directive to vertically align in CSS

directive_verticalAlign

app.directive('verticalAlign', function () {
    return {
        restrict: 'A',
        link: function (scope, elm, attrs) {
            var childHeight = elm[0].clientHeight;
            var parentHeight = elm[0].parentElement.clientHeight;
            var offset = (parentHeight - childHeight) / 2;          
            elm[0].style.paddingTop = offset + 'px';
        }
    }
});