AngularJS:指令无法访问隔离范围对象

Question

我试图在我的指令中使用Isolate范围设置一些默认值.基本上,我需要在绑定指令时使用scope对象进行一些DOM操作.以下是我的代码:

控制器:

angular.module('ctrl').controller('TempCtrl', function($scope, $location, $window, $timeout, RestService, CommonSerivce) {

$scope.showAppEditWindow = function() {
    //Binding the directive isolate scope objects with parent scope objects
    $scope.asAppObj = $scope.appObj;
    $scope.asAppSubs = $scope.appSubscriptions;

    //Making Initial Settings
    CommonSerivce.broadcastFunction('doDirectiveBroadcast', "");
};

服务:

angular.module('Services').factory('CommonSerivce', function ($rootScope) {
return {       
    broadcastFunction: function(listener, args) {
        $rootScope.$broadcast(listener, args);
    }
};

指示:

angular.module('directives').directive('tempDirective', function() {
return {
    restrict : 'E',
    scope:{
        appObj:'=asAppObj',
        appSubs: '=asAppSubs'
    },
    link : function(scope, element, attrs) {},
    controller : function ($scope,Services,CommonSerivce) {         
        //Broadcast Listener 
        $scope.$on('doDirectiveBroadcast', function (event, args) {
            $scope.setDefaults();
        });

        $scope.setDefaults = function() {
            //Setting Default Value
            alert(JSON.stringify($scope.appSubs)); //Coming as undefined            
        };
    },
    templateUrl:"../template.html"
    };
});

自定义指令元素:

<temp-directive as-app-obj="asAppObj" as-app-subs="asAppSubs" />

现在,问题是在尝试访问默认方法inside指令中的隔离范围时,我得到一个未定义的值,而数据即将到来并且正在绑定到DOM.如何访问广播监听器中的隔离范围并修改指令模板HTML？还有另外一个处理这个问题吗？

Answer 1

问题是:当时angular 还没有更新它的绑定.

你不应该像这样访问你的变量,尝试使用angular js绑定机制将它绑定到视图(例如使用$ watch).绑定到父范围变量意味着您是被动的,只是监听更改并更新其他变量或视图.这就是我们应该如何使用角度.

如果您仍需要访问它.您可以尝试使用$ timeout进行解决方法

$scope.setDefaults = function() {
    $timeout(function () {
        alert(JSON.stringify($scope.appSubs)); //Coming as undefined  
    },0);          
};

DEMO

最好使用$ watch

 angular.module('ctrl', []).controller('TempCtrl', function ($scope, $location, $rootScope) {
         $scope.appSubscriptions = "Subscriptions";
         $scope.appObj = "Objs";
         $scope.showAppEditWindow = function () {
             //Binding the directive isolate scope objects with parent scope objects
             $scope.asAppObj = $scope.appObj;
             $scope.asAppSubs = $scope.appSubscriptions;

         };
     });

     angular.module('ctrl').directive('tempDirective', function () {
         return {
             restrict: 'E',
             replace: true,
             scope: {
                 appObj: '=asAppObj',
                 appSubs: '=asAppSubs'
             },
             link: function (scope, element, attrs) {

             },
             controller: function ($scope, $timeout) {
                 $scope.$watch("appSubs",function(newValue,OldValue,scope){
                     if (newValue){ 
                         alert(JSON.stringify(newValue)); 
                     }
                 });
             },
             template: "<div>{{appSubs}}</div>"
         };
     });

DEMO

通过使用$ watch,您无需在这种情况下广播您的活动.