Javascript 如何在每个助手的 Handlebars 中获取索引？

How to get index in Handlebars each helper?

提问by thunderboltz

I'm using Handlebars for templating in my project. Is there a way to get the index of the current iteration of an "each" helper in Handlebars?

我在我的项目中使用 Handlebars 进行模板化。有没有办法在 Handlebars 中获取“每个”助手的当前迭代索引？

<tbody>
     {{#each item}}
         <tr>
            <td><!--HOW TO GET ARRAY INDEX HERE?--></td>
            <td>{{this.key}}</td>
            <td>{{this.value}}</td>
         </tr>
     {{/each}}
</tbody>

回答by ro60

In the newer versions of Handlebars index (or key in the case of object iteration) is provided by default with the standard each helper.

在较新版本的 Handlebars 索引（或对象迭代情况下的键）中，默认情况下为每个助手提供了标准。

---

---

snippet from : https://github.com/wycats/handlebars.js/issues/250#issuecomment-9514811

摘自：https: //github.com/wycats/handlebars.js/issues/250#issuecomment-9514811

The index of the current array item has been available for some time now via @index:

当前数组项的索引已经通过@index 提供了一段时间：

{{#each array}}
    {{@index}}: {{this}}
{{/each}}

For object iteration, use @key instead:

对于对象迭代，请改用 @key：

{{#each object}}
    {{@key}}: {{this}}
{{/each}} 

回答by Ryan Lewis

This has changed in the newer versions of Ember.

这在较新版本的 Ember 中发生了变化。

For arrays:

对于数组：

{{#each array}}
    {{_view.contentIndex}}: {{this}}
{{/each}}

It looks like the #each block no longer works on objects. My suggestion is to roll your own helper function for it.

看起来 #each 块不再适用于对象。我的建议是为它滚动你自己的辅助函数。

Thanks for this tip.

谢谢你的提示。

回答by Naitik

I know this is too late. But i solved this issue with following Code:

我知道这已经太晚了。但我用以下代码解决了这个问题：

Java Script:

Java脚本：

Handlebars.registerHelper('eachData', function(context, options) {
      var fn = options.fn, inverse = options.inverse, ctx;
      var ret = "";

      if(context && context.length > 0) {
        for(var i=0, j=context.length; i<j; i++) {
          ctx = Object.create(context[i]);
          ctx.index = i;
          ret = ret + fn(ctx);
        }
      } else {
        ret = inverse(this);
      }
      return ret;
}); 

HTML:

HTML：

{{#eachData items}}
 {{index}} // You got here start with 0 index
{{/eachData}}

if you want start your index with 1 you should do following code:

如果你想用 1 开始你的索引，你应该执行以下代码：

Javascript:

Javascript：

Handlebars.registerHelper('eachData', function(context, options) {
      var fn = options.fn, inverse = options.inverse, ctx;
      var ret = "";

      if(context && context.length > 0) {
        for(var i=0, j=context.length; i<j; i++) {
          ctx = Object.create(context[i]);
          ctx.index = i;
          ret = ret + fn(ctx);
        }
      } else {
        ret = inverse(this);
      }
      return ret;
    }); 

Handlebars.registerHelper("math", function(lvalue, operator, rvalue, options) {
    lvalue = parseFloat(lvalue);
    rvalue = parseFloat(rvalue);

    return {
        "+": lvalue + rvalue
    }[operator];
});

HTML:

HTML：

{{#eachData items}}
     {{math index "+" 1}} // You got here start with 1 index
 {{/eachData}}

Thanks.

谢谢。

回答by Ember Freak

In handlebar version 3.0 onwards,

在车把版本 3.0 以后，

{{#each users as |user userId|}}
  Id: {{userId}} Name: {{user.name}}
{{/each}}

In this particular example, user will have the same value as the current context and userId will have the index value for the iteration. Refer - http://handlebarsjs.com/block_helpers.htmlin block helpers section

在此特定示例中，用户将具有与当前上下文相同的值，而 userId 将具有迭代的索引值。参考 - http://handlebarsjs.com/block_helpers.html在块助手部分

回答by RegarBoy

Arrays:

数组：

{{#each array}}
    {{@index}}: {{this}}
{{/each}}

If you have arrays of objects... you can iterate through the children:

如果您有对象数组……您可以遍历子项：

{{#each array}}
    //each this = { key: value, key: value, ...}
    {{#each this}}
        //each key=@key and value=this of child object 
        {{@key}}: {{this}}
        //Or get index number of parent array looping
        {{@../index}}
    {{/each}}
{{/each}}

Objects:

对象：

{{#each object}}
    {{@key}}: {{this}}
{{/each}} 

If you have nested objects you can access the keyof parent object with {{@../key}}

如果您有嵌套对象，则可以key使用 {{@../key}}

回答by anonymous

In handlebar version 4.0 onwards,

在车把版本 4.0 以后，

{{#list array}}
  {{@index}} 
{{/list}}