javascript AngularJS：在控制器中初始化嵌套范围变量
声明：本页面是StackOverFlow热门问题的中英对照翻译，遵循CC BY-SA 4.0协议，如果您需要使用它，必须同样遵循CC BY-SA许可，注明原文地址和作者信息，同时你必须将它归于原作者（不是我）：StackOverFlow
原文地址: http://stackoverflow.com/questions/22564977/
Warning: these are provided under cc-by-sa 4.0 license. You are free to use/share it, But you must attribute it to the original authors (not me):
StackOverFlow
AngularJS: Initialize nested scope variables in controller
提问by Tyler
I like to keep my namespace of model names clean and descriptive, so I use nested model variables like this (where month and year are nested in service):
我喜欢保持我的模型名称命名空间干净和描述性，所以我使用这样的嵌套模型变量（其中月份和年份嵌套在服务中）：
<form data-ng-submit="submit()">
<select data-ng-model="service.month" data-ng-options="m for m in months"/>
<input data-ng-model="service.year"/> {{ service.year }}
<input type="submit"/>
</form>
And in my controller, I want to set $scope.service.monthand $scope.service.yearto initial values, but I get a javascript error Cannot set property 'year' of undefined, so I'm guessing the DOM hasn't been parsed and all the $scopevariables haven't been created yet. How can I have some code wait to run until the DOM has been parsed by Angular and all the models have been created?
在我的控制器中，我想设置$scope.service.month和$scope.service.year初始值，但是我收到一个 javascript 错误Cannot set property 'year' of undefined，所以我猜 DOM 还没有被解析，所有的$scope变量还没有被创建。如何让一些代码等待运行，直到 DOM 被 Angular 解析并且所有模型都已创建？
Here's my controller:
这是我的控制器：
mod.controller('AddServiceCtrl', [
'$scope',
'$rootScope',
function($scope, $rootScope) {
var date = new Date();
$scope.months = ['Jan', 'Feb', 'Mar', 'Apr', 'May', 'Jun', 'Jul', 'Aug', 'Sep', 'Oct', 'Nov', 'Dec'];
$scope.service.year = 2014;
$scope.submit = function(){
};
}])
采纳答案by mpm
$scope.service= {month:'Mar',year:2014};
AngularJS is still JavaScript.
AngularJS 仍然是 JavaScript。
The AngularJS team unfortunately chose to name what is actually a presenter (or a view model), a controller. It might not sound that important, but conceptually it is in order to understand what controllersdo.
不幸的是，AngularJS 团队选择将实际的演示者（或视图模型）命名为controller. 这听起来可能不那么重要，但从概念上讲，它是为了理解做controllers什么。
回答by ryan.l
The problem is that the $scope.serviceobject is undefined, so it is failing to define a yearproperty on it inside the controller, not the view. To make this work, you must set serviceobject on the scope like this:
问题是$scope.service对象是undefined，所以它无法year在控制器内部定义属性，而不是视图。要完成这项工作，您必须service像这样在作用域上设置对象：
$scope.service = {};
then you can define default values for the model on the controller orin the view:
然后您可以在控制器或视图中为模型定义默认值：
Controller option
控制器选项
$scope.service = {};
$scope.service.year = 2014;
or
或者
$scope.service = {
year: 2014,
month: $scope.months[3] // to default to 'Apr'
};
View Option
查看选项
<form data-ng-submit="submit()"
data-ng-init="service.year=2014; service.month=months[3]">
...
</form>
either way, you must create the serviceobject on the scope in order to define properties thereon. use object literal notation ({}) to create it.
无论哪种方式，您都必须service在作用域上创建对象才能在其上定义属性。使用对象文字符号 ( {}) 来创建它。
