单击是否启用当前元素

Question

我希望create指令检查当前元素的类，如果没有禁用它，则调用一个函数。

但它不起作用，我看不出任何错误。

app.directive("clickIfEnabled", ['$parse', '$rootScope', function ($parse, $rootScope) {
    return {
        restrict: 'A',
        link: function ($element, attr) {
            // We expose the powerful $event object on the scope that provides access to the Window,
            // etc. that isn't protected by the fast paths in $parse.  We explicitly request better
            // checks at the cost of speed since event handler expressions are not executed as
            // frequently as regular change detection.
            var eventname = "click-if-enabled";
            var fn = $parse(attr.attr[eventname], /* interceptorFn */ null, /* expensiveChecks */ true);
            return function ngEventHandler(scope, element) {
                element.on("click", function (event) {
                    var callback = function () {
                        fn(scope, { $event: event });
                    };
                    //if (forceAsyncEvents[eventName] && $rootScope.$$phase) {
                    //    scope.$evalAsync(callback);
                    //} else {
                        scope.$apply(callback);
                  //  }
                });
            };
        }
    };
}]);

演示：http://jsfiddle.net/SbrKj/116/ 只是应该显示警报（“做某事”）