在 ng-options 处选择默认值 [英] Select default value at ng-options

问题描述

我有这个代码和信息:

$scope.options = [
  { id: 1, label: "My label" },
  { id: 2, label: "My label 2" }
];
$scope.selected = 2;

<select ng-options="opt.label for opt in options" ng-model="selected">
  <option value="">Select one</option>
</select>

然而，选项是这样创建的:

However, the options are created like this:

<select ng-options="opt.label for opt in options" ng-model="selected">
  <option value="">Select one</option>
  <option value="0">My label</option>
  <option value="1">My label 2</option>
</select>

如何将所选选项设置为我的标签 2?我知道这是可以做到的:

How can I set the selected option to My label 2? I know it can be done:

$scope.selected = $scope.options[1];

但我的问题是该选项是在指令中创建的，当时我不知道 1) $scope.options 有多少个值，也不知道 2) 的索引是什么数据库中选择的选项.我唯一知道的是 id(在对象中).

But my problem is that option is created in a directive, and at that moment I don't know 1) how many values has $scope.options, nor 2) what is the index of the selected option in database. The only thing I know is the id (which is in the object).

我的指令的 html 是这样的:

The html of my directive is something like this:

<select ng-switch-when="select" ng-model="form.model[element.model]" ng-options="{{element.rule}}"></select>

element.rule 在哪里:

rule: "role.role for role in element.options"

并且 element.options 有带选项的数组，form.model[element.model] 有选择的选项的 id.

And element.options has the array with options, and form.model[element.model] has the id of the option selected.

如何获取数组 $scope.options 中 ID 为 X 的元素的索引?我很确定这会给我解决方案，但我不知道该怎么做...

How can I get the index of the element with ID X in the array $scope.options? I'm very sure that will give me the solution, but I don't know how to do it...

推荐答案

只需在启动控制器时设置正确的模型值即可.如果您使用 filter 知道 ID，则可以轻松获得正确的数组值:

Just set the correct model value when initiating the controller. You can easily get the correct array value if you know the ID by using a filter:

$scope.selected = $filter('filter')($scope.options, {id: 2})[0];

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