ng-repeat 和 ng-switch 在同一个元素上不起作用 [英] ng-repeat and ng-switch doesn't work on same element

问题描述

JS

$scope.mode = "test"$scope.array = ['test1', 'test2', 'test3']

HTML

<div ng-repeat="数组中的项目" ng-switch-when="test">测试项目}}

当我执行上述操作时，我得到的输出是

测试测试测试

它似乎无法访问项目.如果我删除 ng-switch-when 那么它就可以正常工作.

解决方案

这是因为 ng-switch 创建了一个子作用域，同样适用于 ng-repeat.ng-repeat 优先运行 1000 和 ng-switch 在 800.因此 ng-repeat 在每个重复的 div 元素上创建的子作用域被 ng-switch 覆盖，因此分配了 ng-repeat元素上的子作用域最终消失了.一种可能的方法是将 ng-switch 包装在 ng-repeat 之外，因为您无论如何都不想为每个重复元素计算 ng-switch 表达式.这是 1.2 版本.

现在从 1.3.x 版本的 angular 起，ng-switch 的优先级已经修改为 1200 和 ng-repeat 保持在 1000，因此 ng-repeated 范围将占上风，因为它现在的优先级较低，并且在这种情况下可以工作.

Plnkr

JS

$scope.mode = "test"
$scope.array = ['test1', 'test2', 'test3']

HTML

<div ng-switch on="mode">
    <div ng-repeat="item in array" ng-switch-when="test">
        Test {{item}}
    </div>
</div>

When I do this the above, the output I get is

Test Test Test

It can't seem to access item. If I remove the ng-switch-when then it works fine.

解决方案

It is because ng-switch creates a child scope and same applies for ng-repeat. ng-repeat runs at priority 1000 and ng-switch at 800. So the child scope created by ng-repeat on each of the repeated div elements gets overwritten by ng-switch, so the ng-repeat assigned child scope on the element is gone ultimately. A possibly way could be to wrap your ng-switch outside ng-repeat since you anyways do not want to evaluate the ng-switch expression for every repeated element. This is with the 1.2 version.

Now from 1.3.x version of angular the priority of ng-switch has been revise to 1200 and ng-repeat remains at 1000, so ng-repeated scope will prevail, since it is of lower priority now and it will work in that case.

Plnkr

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