在knockout视图中访问$ parent的$ parent - 嵌套上下文

Question

为简洁起见而更新

如何在嵌套的Knockout foreach/with bindings中引用$ parents'$ parent？

示例 -

    <!-- ko foreach: grandParent -->
        <tr>
            <!-- ko foreach: $parent.parents --> // <-- Doesn't work
                <!-- ko foreach: children -->
                    <td data-bind="if: favToy().name == $parent.$parent.favToy().name">
                        <span data-bind="text: favToy().name"></span>
                    </td>
                <!-- /ko -->
            <!-- /ko -->
        </tr>
    <!-- /ko -->

原版的

很抱歉这个令人困惑的问题,但我试图达到二级父级的值,以检查当前上下文中的值(如下所示),只显示一个跨度,如果它匹配$ parent的$ parent的值(呃!)

    <!-- ko foreach: grandParent -->
        <tr>
            <!-- ko foreach: $parent.parents -->
                <!-- ko foreach: children -->
                    <td data-bind="if: favToy().name == $parent.$parent.favToy().name">
                        <span data-bind="text: favToy().name"></span>
                    </td>
                <!-- /ko -->
            <!-- /ko -->
        </tr>
    <!-- /ko -->

以这种方式做起来会更容易,但从我所看到的这是不可能的,或者我做错了:)

    <!-- ko foreach: grandParent -->
        <tr>
            <!-- ko foreach: $parent.parents -->
                <!-- ko foreach: children ? favToy().name == $parent.$parent.favToy().name -->
                    <td  data-bind="text: favToy().name"></td>
                <!-- /ko -->
            <!-- /ko -->
        </tr>
    <!-- /ko -->

任何帮助将不胜感激.

Answer 1

Use the $parents array, the grandparent would be $parents[1]. You may also be able to use $root if the grandParent object in your example is the topmost parent.

From the docs:

$parents

This is an array representing all of the parent view models:

$parents[0] is the view model from the parent context (i.e., it’s the same as $parent)

$parents[1] is the view model from the grandparent context

$parents[2] is the view model from the great-grandparent context

… and so on.

$root

这是根上下文中的主视图模型对象,即最顶层的父上下文.它通常是传递给ko.applyBindings的对象.它相当于$ parents [$ parents.length - 1].

Answer 2

你可以用$parentContext.$parent.

$parentContext提供了许多有用的性能,如($data,$parent,$index,...)