<!-- ag-textbox is my directive -->
<input ag-textbox ag-grid-class="col-md-4" class="form-control" id="age" type="text"  ag-name="Age" ng-model="age" ag-formname="newform" required />

var fDiv = angular.element("<div class='" + agGridClass + "' "
                            + "ng-class={'has-error':" + agFormName + "." + agName + ".$invalid}>");
element.wrap(fDiv);
$compile(element.contents())(scope);

element.html('').append(firstDiv + inputText + otherDiv);
$compile(element.contents())(scope);

element.wrap(fDiv);
$compile(element.parent().contents())(scope);

var fDiv = angular.element("<div class='" + agGridClass + "' "
               + "ng-class="{'has-error':" + agFormName + "." + agName + ".$invalid}"></div>");