基于查找的车把状况

Question

我有以下数据结构：

{
    things: [
        "desk",
        "chair",
        "pen",
        "book",
        "lamp"
    ],
    owners: [
        "Julia",
        "Sandra",
        "John",
        "Paul"
    ]
}

工作原理：

此handleblars模板：

{{#each things}}
    <p>This {{this}} belongs to {{lookup ../owners @index}}</p>
{{/each}}

正确输出：

This desk belongs to Julia
This chair belongs to Sandra
This pen belongs to John
This book belongs to Paul
This lamp belongs to

什么不起作用：

现在，我想添加一个条件，因为最后一个thing可能没有owner。模板将如下所示：

{{#each things}}
    {{#if lookup ../owners @index}}
        <p>This {{this}} belongs to {{lookup ../owners @index}}</p>
    {{else}}
        <p>...But this {{this}} belongs to nobody</p>
    {{/if}}
{{/each}}

输出：

This desk belongs to Julia
This chair belongs to Sandra
This pen belongs to John
This book belongs to Paul
...But this lamp belongs to nobody

不幸的是，这{{#if lookup ../owners @index}}东西行不通。

我的问题：是否可以使用内置的Handlebars帮助器实现此目的，还是必须编写自定义帮助器？

Answer 1

实际上，您可以使用子表达式执行您想做的事情：

{{#if (lookup ../owners @index)}}

奇迹般有效。（来源：Handlebars网站）