定制快递把手如果帮手(Custom Express Handlebars If Helper)

 我使用express-handlebars遍历一个数组对象，并且每创建一个dom元素都应该有一个特定的属性。 
 
 像这样的东西： 
 
<div class=""></div>
<div></div>
<div class=""></div>
<div></div>
 
 我注意到有一个包含迭代索引的@size值。 
 
 我的代码到目前为止是这样的： 
 
{{#each todoGroups}}
         {{#if @index}}
            <div class=""></div>
         {{/if}}
{{/each}}
 
 但是，如何向if语句添加一个条件，该语句只对每个第二项都计算为true ？ 
 
 我被困在试图实现这个功能，这是迄今为止我的方法： 
 
function hbsHelpers(hbs) {
  return hbs.create({
    helpers: { // This was missing
      isEven: function(value, options) {

      },

      // More helpers...
    },

  });
}

I'm iterating over an array object utilizing express-handlebars and only every second dom element which is created should have a specific attribute.
 
Something like this: 
 
<div class=""></div>
<div></div>
<div class=""></div>
<div></div>
 
I noticed that there is a @size value which contains the index of the iteration.
 
My code so far is looking like this: 
 
{{#each todoGroups}}
         {{#if @index}}
            <div class=""></div>
         {{/if}}
{{/each}}
 
But how do I add a condition to the if statement which only evaluates to true for every second item?
 
I'm stuck trying to implement this functionality this is my approach so far:
 
function hbsHelpers(hbs) {
  return hbs.create({
    helpers: { // This was missing
      isEven: function(value, options) {

      },

      // More helpers...
    },

  });
}

原文：https://stackoverflow.com/questions/45620383