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AngularJS:指令无法访问隔离作用域对象

angularjs

我试图在我的指令中使用隔离范围放置一些默认值。基本上,绑定指令后,我需要使用scope对象进行一些DOM操作。下面是我的代码:

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,当尝试在指令内部的默认方法中访问隔离范围时,我在获取数据并将其绑定到DOM的同时获得了未定义的值。如何访问广播侦听器中的隔离作用域并修改指令模板HTML?还有另一个处理这个的麻烦吗?


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2020-07-04

共1个答案

小编典典

问题是:那时angular 尚未更新其绑定

您不应该这样访问变量,请尝试使用angular js绑定机制将其绑定到 视图 (例如,使用$ watch)。绑定到父作用域变量意味着您是
被动的
,只需侦听更改并更新 其他变量 视图即可 。这就是我们应该使用角度的方式。

如果您仍然需要访问它。您可以使用$
超时尝试解决方法

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

演示

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>"
         };
     });

演示

通过使用$ watch,在这种情况下,您无需广播事件。

2020-07-04