使用JSON定义Handlebars JS partials：在JSON中定义部分的名称，并使Handlebars JS呈现部分

Question

我们使用config.json来设置基于Handlebars的布局以从模板生成电子邮件。该json配置包含部分名称和该部分的内容（图像，标题和说明）。

的/分音/ ..分别称为：

• primary.html
• secondary.html

此处是/data/config.json一个例子 - 您可以看到“模块”节点包含部分及其内容：

{ 
    "subject": "my email subject", 
    "pretext": "this is the pretext text", 
    "modules": { 
     "primary":{ 
      "image": { 
       "src": "primary-hero.jpg", 
       "alt": "This is the primary image" 
      }, 
      "headline": "Primary Headline", 
      "description": "Lorem ipsum dolor sit amet, consectetur adipisicing elit. Cupiditate nulla ipsam ratione rem incidunt quasi quos, possimus cumque neque corporis, dignissimos deserunt perspiciatis totam. Totam itaque distinctio deserunt fugiat nostrum." 
      }, 
     "secondary":{ 
      "image": { 
       "src": "secondary-hero.jpg", 
       "alt": "This is the secondary hero image" 
      }, 
      "headline": "Secondary Headline", 
      "description": "Lorem ipsum dolor sit amet, consectetur adipisicing elit. Cupiditate nulla ipsam ratione rem incidunt quasi quos, possimus cumque neque corporis, dignissimos deserunt perspiciatis totam. Totam itaque distinctio deserunt fugiat nostrum." 
      }, 
    } 
} 

我目前有一个句柄循环/pages/index.html工作，但使用比较帮手。显然，这种做法有问题，因为它迫使任意渲染顺序，还可以当部分在JSON反复失败：

{{#each config.modules}} 
    {{#ifEqual @key "primary"}} 
    {{> primary}} 
    {{/ifEqual}} 
    {{#ifEqual @key "secondary"}} 
    {{> secondary}} 
    {{/ifEqual}} 
{{/each}} 

更理想的是，循环应该是这样的：

{{#each config.modules}} 
    {{ > @key }} 
{{/each}} 

那当然失败：

Panini: rendering error ocurred. 
{ [Error: The partial @key could not be found] 
    description: undefined, 
    fileName: undefined, 
    lineNumber: undefined, 
    message: 'The partial @key could not be found', 
    name: 'Error', 
    number: undefined } 

有没有什么办法做到这一点 - 通过json传递部分名称？

Answer 1

我不是很熟悉的手把，所以有可能是一个更好的办法，但我想出了这个：

Handlebars.registerHelper('renderPartial', (key) => key); 

要使用：

{{#each config.modules}} 
    {{> (renderPartial @key) }} 
{{/each}} 

Answer 2

我已经算起来基于此线程：https://github.com/ericf/express-handlebars/issues/121

“子表达式不解决变量，所以[名称]必须是一个函数。”

我创建了一个助手，简单地返回一个字符串：

getPartial

module.exports = function(name) { 
    return name; 
}; 

在车把上渲染循环：

{{#each config.modules}} 
    {{> (getPartial @key) }} 
{{/each}} 

现在呈现没有错误。但是，在JSON中重复部分时，它似乎仍然存在问题，它只会呈现该部分的单个实例。

所以，虽然“二次”在JSON中包含了两次，它只能呈现部分一次：

{ 
    "subject": "my email subject", 
    "pretext": "this is the pretext text", 
    "modules": { 
     "primary":{ 
      "image": { 
       "src": "primary-hero.jpg", 
       "alt": "This is the primary image" 
      }, 
      "headline": "Primary Headline", 
      "description": "Lorem ipsum dolor sit amet, consectetur adipisicing elit. Cupiditate nulla ipsam ratione rem incidunt quasi quos, possimus cumque neque corporis, dignissimos deserunt perspiciatis totam. Totam itaque distinctio deserunt fugiat nostrum." 
      }, 
     "secondary":{ 
      "image": { 
       "src": "secondary-hero.jpg", 
       "alt": "This is the secondary hero image" 
      }, 
      "headline": "Secondary Headline", 
      "description": "Lorem ipsum dolor sit amet, consectetur adipisicing elit. Cupiditate nulla ipsam ratione rem incidunt quasi quos, possimus cumque neque corporis, dignissimos deserunt perspiciatis totam. Totam itaque distinctio deserunt fugiat nostrum." 
      }, 
     "secondary":{ 
      "image": { 
       "src": "secondary-hero.jpg", 
       "alt": "This is the secondary hero image" 
      }, 
      "headline": "Secondary Headline", 
      "description": "Lorem ipsum dolor sit amet, consectetur adipisicing elit. Cupiditate nulla ipsam ratione rem incidunt quasi quos, possimus cumque neque corporis, dignissimos deserunt perspiciatis totam. Totam itaque distinctio deserunt fugiat nostrum." 
      }, 
    } 
} 

这必须直接相关的事实，渲染列表是一个循环和@密钥必须是唯一的？如果我直接列出部分，它会呈现“次要”预期的两倍：

{{> primary}} 
{{> secondary}} 
{{> secondary}}