如何在淘汰赛视图中引用此内容 [英] How reference this in knockout view

问题描述

问候，我今天有一个非常简单的问题要问你.

Greetings all I have a very simple question for you today.

我有这个标记(视图):

I have this markup (view):

<div class="cards" data-bind="sortable: { data: cards, afterMove: cardMoved }">
    <div class="card">
        <div><span data-bind="text: title"></span></div>
        <div class="dnnRight" data-bind="if: firstMatch(this, id)">
            <a href="#" class="dnnSecondaryAction" data-bind="click: $root.openCard"><%= LocalizeString("EditBtn") %></a>
            <a href="#" class="dnnSecondaryAction" data-bind="click: $parent.removeCard"><%= LocalizeString("DeleteBtn") %></a>
        </div>
    </div>
</div>

基本上，它在 card 模型上具有 foreach 数据绑定.我已经编写了一个足够简单的函数，可以根据卡模型定义中的 id 参数找到第一个匹配元素.但是我需要能够引用有问题的卡，以便在我的函数中访问它的可观察参数.

Basically it has a foreach data-binding on card model. I have written a simple enough function to find first matching element based on id parameter which lives inside card model definition. But I need to be able to refer to the card in question in order to access it's observable parameters within my function.

如何参考个人卡?此关键字不适合我.

How can I reference individual card? this keyword isn't working for me.

正如我指出的那样，我一直在尝试敲除文档绑定上下文，但是大多数情况下，我都会遇到错误.

As I pointed out I've been trying everything from knockout documentation Binding context but most of the time I end up with an error.

Error: Unable to process binding "foreach: function (){return lists }" Message: Unable to process binding "sortable: function (){return { data:cards,afterMove:cardMoved} }" Message: Unable to process binding "if: function (){return firstMatch($data,2) }" Message: Cannot write a value to a ko.computed unless you specify a 'write' option. If you wish to read the current value, don't pass any parameters.

更新2

实际上，如果在 if 调用 firstMatch()时我将函数调整为仅以 id 作为参考，这可能会有所帮助能够使用 this.property

Update 2

Actually it might help if I adjust my function to just take id as a reference becuase when if calls firstMatch() I should be able to access members ìn the current context using this.property

    //identify the first matching item by id
    self.firstMatch = ko.computed(function (id) {
        var search = false;
        ko.utils.arrayForEach(self.members, function (member) {
            if (member.id == id) {
                search = true;
            }
        });
        return search;
    });

推荐答案

检查 self.members()是否具有值.如果为null，则不会循环

Check whether self.members() have values or not. If it is null it will not go in the loop

这篇关于如何在淘汰赛视图中引用此内容的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！