$watch 不会触发数据更改 [英] $watch not firing on data change
问题描述
我有一个针对 ui-select2 下拉列表模型的手表设置(来自 ui-bootstrap).手表在加载时触发，但不会在数据更改时触发，我不知道为什么.
不应用模型更改或不使用第三个参数进行相等比较(至少从我的代码来看)不是常见的问题.
我需要做什么才能让它启动?
我修复了一些问题.
http://plnkr.co/edit/5Zaln7QT2gETVcGiMdoW?p=preview
JS
var myMod = angular.module("myApp",[]).controller("MainController", function($scope){$scope.myModel = {selectedId:null};}).controller("DetailController",function($scope){$scope.items = [1,2,3,4];$scope.watchHitCount = 0;$scope.$watch('myModel.selectedId', function(newVal, oldVal){console.log(newVal + " " + oldVal);$scope.watchHitCount++;}，真的);});index.html
<div ng-controller="MainController"><ng-include src="'detail.html'" ng-controller="DetailController"></ng-include>detail.html
观看命中:{{watchHitCount}}</pre><pre>选择的值:{{myModel.selectedId}}</pre><select ng-model="myModel.selectedId" ui-select2=""><选项></选项><option ng-repeat="item in items" value="{{item}}">{{item}}</option></选择>它抱怨找不到控制器，所以我按照通常的方式使用命名的 ng-app 和一个声明了控制器的模块进行了设置.
我还添加了一个对象来保存模型中的值.使用 $scope 对象作为模型是不好的做法，而您的作用域应该引用作为模型的对象.
I have a watch setup against the model of a ui-select2 dropdown (from ui-bootstrap). The watch fires on load but not on data changes and I can't figure out why.
It isn't the usual problem of not $apply'ing the model change or not using the third parameter for equality comparison (at least from my code).
What do I need to do to get it to fire?
Here is a plunk demonstrating the issue.
I fixed some stuff.
http://plnkr.co/edit/5Zaln7QT2gETVcGiMdoW?p=preview
The JS
var myMod = angular.module("myApp",[]).controller("MainController", function($scope){
$scope.myModel = {selectedId:null};
}).controller("DetailController",function($scope){
$scope.items = [1,2,3,4];
$scope.watchHitCount = 0;
$scope.$watch('myModel.selectedId', function(newVal, oldVal){
console.log(newVal + " " + oldVal);
$scope.watchHitCount++;
},true);
});
The index.html
<body ng-app="myApp">
<div ng-controller="MainController">
<ng-include src="'detail.html'" ng-controller="DetailController"></ng-include>
</div>
</body>
The detail.html
<pre>watch hit: {{watchHitCount}}</pre>
<pre>selected value: {{myModel.selectedId}}</pre>
<select ng-model="myModel.selectedId" ui-select2="">
<option></option>
<option ng-repeat="item in items" value="{{item}}">{{item}}</option>
</select>
It was complaining about not finding the controller so I set it up the way I normally would with a named ng-app and a module declared that has controllers defined on it.
I also added an object to hold the value in your model. It is bad practice to use the $scope object as your model, instead your scope should refer to an object that is your model.
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