如何使用 angularJS 正确绑定指令和控制器之间的范围

问：

我正在尝试使用 anugularJS 生成一个 n 级分层无序列表，并且已经能够成功做到这一点。但是现在，我在指令和控制器之间遇到了范围问题。我需要从指令模板中通过 ng-click 调用的函数中更改父级的作用域属性。

查看 http://jsfiddle.net/ahonaker/ADukg/2046/ - 这是 JS

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

//myApp.directive('myDirective', function() {});
//myApp.factory('myService', function() {});

function MyCtrl($scope) {
    $scope.itemselected = "None";
    $scope.organizations = {
        "_id": "SEC Power Generation",
        "Entity": "OPUNITS",
        "EntityIDAttribute": "OPUNIT_SEQ_ID",
        "EntityID": 2,
        "descendants": ["Eastern Conf Business Unit", "Western Conf Business Unit", "Atlanta", "Sewanee"],
        children: [{
            "_id": "Eastern Conf Business Unit",
            "Entity": "",
            "EntityIDAttribute": "",
            "EntityID": null,
            "parent": "SEC Power Generation",
            "descendants": ["Lexington", "Columbia", "Knoxville", "Nashville"],
            children: [{
                "_id": "Lexington",
                "Entity": "OPUNITS",
                "EntityIDAttribute": "OPUNIT_SEQ_ID",
                "EntityID": 10,
                "parent": "Eastern Conf Business Unit"
            }, {
                "_id": "Columbia",
                "Entity": "OPUNITS",
                "EntityIDAttribute": "OPUNIT_SEQ_ID",
                "EntityID": 12,
                "parent": "Eastern Conf Business Unit"
            }, {
                "_id": "Knoxville",
                "Entity": "OPUNITS",
                "EntityIDAttribute": "OPUNIT_SEQ_ID",
                "EntityID": 14,
                "parent": "Eastern Conf Business Unit"
            }, {
                "_id": "Nashville",
                "Entity": "OPUNITS",
                "EntityIDAttribute": "OPUNIT_SEQ_ID",
                "EntityID": 4,
                "parent": "Eastern Conf Business Unit"
            }]
        }]
    };

    $scope.itemSelect = function (ID) {
        $scope.itemselected = ID;
    }
}

app.directive('navtree', function () {
    return {
        template: '<ul><navtree-node ng-repeat="item in items" item="item" itemselected="itemselected"></navtree-node></ul>',
        restrict: 'E',
        replace: true,
        scope: {
            items: '='
        }
    };
});

app.directive('navtreeNode', function ($compile) {
    return {
        restrict: 'E',
        template: '<li><a ng-click="itemSelect(item._id)">{{item._id}} - {{itemselected}}</a></li>',
        scope: {
            item: "=",
            itemselected: '='
        },
        controller: 'MyCtrl',
        link: function (scope, elm, attrs) {
            if ((angular.isDefined(scope.item.children)) && (scope.item.children.length > 0)) {
                var children = $compile('<navtree items="item.children"></navtree>')(scope);
                elm.append(children);
            }
        }
    };
});

这是 HTML

<div ng-controller="MyCtrl">
    Selected: {{itemselected}}

    <navtree items="organizations.children"></navtree>
</div>

请注意，该列表是从模型生成的。ng-click 调用函数来设置父作用域属性 （itemselected），但更改仅在本地发生。当我单击某个项目时，预期行为是“已选择：无”应更改为“已选择：xxx”，其中 xxx 是单击的项目。

我是否没有适当地绑定父作用域和指令之间的属性？如何将属性更改传递到父范围？

希望这是清楚的。

提前感谢您的任何帮助。