问如何覆盖现有指令覆盖另一个指令

EN

myDirectives.directive('registerSuccess', function($timeout) {
    return {
        restrict: 'E',
        replace: true,
        template: "<div class='alert alert-success alert-dismissable'></div>",
        link: function(scope, elm, attrs) {

            scope.registerSuccess = function(data) {
                alert(data);
                var msg = "Database "+data+" got registered"
                console.log(elm.attr('style'));
                elm.text((elm.html()||msg));
                elm.removeAttr('style');
                $timeout(function(){
                    elm.hide();
                }, 8000);
            };

        }
    };
});

$scope.registerSuccess(data.dbName);

<register-success style='display:none;'></register-success>