AngularJS ng-if 和作用域 [英] AngularJS ng-if and scopes

问题描述

我正在尝试理解 ng-if 和作用域.据我所知，ng-if 创建了一个新的子作用域.这是我的问题:

查看

<div ng-if="!someCondition"><input ng-model="$parent.someValue2"/>

控制器

$scope.someCondition = true;如果($scope.someCondition){$scope.someValue2 = $scope.someValue1;}

如果 someCondition 设置为 true，那么 someValue2 应该与 someValue1 相同.

我的问题是在两种情况下(真或假)我都无法访问 someValue2.我怎么能做到这一点?

解决方案

是的，ng-if 创建一个新的子作用域

要在 ng-if 中查看模型属性，经验法则是:

请勿将范围用作模型

例如

ng-if='showStuff'//这里我的范围是模型 **INCORRECT**ng-if='someObject.showStuff'//** 正确 **

在 ng-model 中使用对象属性 - 那么，即使 ng-if 创建新的子作用域，父作用域也会发生变化.

要查看工作的 Plunker，请看这里:http://jsfiddle.net/Erk4V/4/

I am trying to understand ng-if and scopes. As I am aware, ng-if creates a new child scope. Here is my issue:

View

<input ng-model="someValue1" />
<div ng-if="!someCondition">
    <input ng-model="$parent.someValue2" />
</div>

Controller

$scope.someCondition = true;

if ($scope.someCondition) {
    $scope.someValue2 = $scope.someValue1;        
}

If someCondition is set to true, then someValue2 should be the same as someValue1.

My problem is that I can't access someValue2 in both situations (true or false). How could I achieve this?

解决方案

Yes, ng-if creates a new child scope

To watch a model property in an ng-if, the rule-of-thumb is:

DO NOT USE THE SCOPE AS MODEL

e.g.

ng-if='showStuff' //here my scope is model **INCORRECT**
ng-if='someObject.showStuff' // ** CORRECT **

Use an object property in ng-model - then, even if ng-if creates the new child scope, the parent scope will have the changes.

To see a working Plunker, look here : http://jsfiddle.net/Erk4V/4/

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