使用 ngRepeat => 将输入绑定到原语数组不可编辑的输入 [英] Binding inputs to an array of primitives using ngRepeat => uneditable inputs

问题描述

这是我的问题的^{(点击放大)}

虚线表示典型的范围继承.
灰线显示子→父关系(即 $parent 引用的内容).
棕色线显示 $$nextSibling.
灰色框是原始值.蓝色框是数组.紫色是物体.

请注意，您在评论中引用的我的 SO 答案是在 1.0.3 出现之前编写的.在 1.0.3 之前，当您在文本框中键入内容时，ngRepeat 子作用域中的 num 值实际上会发生变化.(这些值在父作用域中不可见.)从 1.0.3 开始，ngRepeat 现在将 ngRepeat 作用域 num 值替换为来自 parent/MainCtrl 作用域的 myNumbers<的(未更改的)值/code> 在摘要循环期间的数组.这实质上使输入不可编辑.

解决方法是在 MainCtrl 中使用一组对象:

$scope.myNumbers = [ {value: 10}, {value: 20} ];

然后绑定到ngRepeat中对象的value属性:

<input type="text" ng-model="num.value"><div>当前范围:{{num.value}}</div>

Here is a demo to my problem.

$scope.myNumbers = [10, 20, 30];

<div ng-repeat="num in myNumbers">
    <input type="text" ng-model="num">
    <div>current scope: {{num}}</div>
</div>

Can anyone explain to me why are the inputs uneditable/readonly? If it's by design, what's the rationale behind?

UPDATE 2/20/2014

It looks like this is no longer an issue for v1.2.0+ Demo. But do keep in mind that although the user controls are now editable with the newer angularJS versions, it is the num property in the child scopes, not the parent scope, that get modified. In another words, modifying the values in the user controls does not affect the myNumbers array.

解决方案

Can anyone explain to me why are the inputs uneditable/readonly? If it's by design, what's the rationale behind?

It is by design, as of Angular 1.0.3. Artem has a very good explanation of how 1.0.3+ works when you "bind to each ng-repeat item directly" – i.e.,

<div ng-repeat="num in myNumbers">
  <input type="text" ng-model="num">

When your page initially renders, here's a picture of your scopes (I removed one of the array elements, so the picture would have fewer boxes):

^{(click to enlarge)}

Dashed lines show prototypical scope inheritance.
Gray lines show child → parent relationships (i.e., what $parent references).
Brown lines show $$nextSibling.
Gray boxes are primitive values. Blue boxes are arrays. Purple are objects.

Note that the SO answer of mine that you referenced in a comment was written before 1.0.3 came out. Before 1.0.3, the num values in the ngRepeat child scopes would actually change when you typed into the text boxes. (These values would not be visible in the parent scope.) Since 1.0.3, ngRepeat now replaces the ngRepeat scope num values with the (unchanged) values from the parent/MainCtrl scope's myNumbers array during a digest cycle. This essentially makes the inputs uneditable.

The fix is to use an array of objects in your MainCtrl:

$scope.myNumbers = [ {value: 10}, {value: 20} ];

and then bind to the value property of the object in the ngRepeat:

<div ng-repeat="num in myNumbers">
  <input type="text" ng-model="num.value">
  <div>current scope: {{num.value}}</div>

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