javascript - Angular 数组不会显示嵌套数组

Question

我正在尝试在 AngularJS 中显示嵌套数组。但是，我无法让它工作。

Controller :

$scope.selected_category = [];
$scope.categories = [];

$scope.getCategories = function() {
    ItemService.getCategories().success(function(categories) {
        $scope.categories = categories;
    });
}

$scope.getCategories();

表单设置$scope.selected_category

<select class="form-control" ng-model="selected_category">
    <option ng-repeat="category in categories" value="{{ category }}">{{ category.name }}</option>
</select>

所以...现在打印 {{ selected_category }} 显示预期的数组，其中包含 subcategory 数组:

{
  "id": "1",
  "name": "clothing",
  "subcategories": [
    {
      "id": "1",
      "name": "jackets",
      "item_category_id": "1"
    },
    {
      "id": "2",
      "name": "jeans",
      "item_category_id": "1"
    },
    {
      "id": "3",
      "name": "sweaters",
      "item_category_id": "1"
    }
  ]
}

然而，当我尝试执行 selected_category.subcategories 时，我什么也没得到。这是为什么？

这是一个重现问题的笨蛋:http://plnkr.co/edit/AtqpXogmItdSupEZGt7R?p=preview

Answer 1

使用ng-options:

<select class="form-control" ng-model="selected_category" 
ng-options="category as category.name for category in categories">
</select>