Rails 4.0 每 3 个每个 div 循环然后应用类

Question

我在下面循环播放

- @published_only.each do |p|
  .movie.effect
    = image_tag(p.poster_url(:thumb), class: "img")
    .mini-desc
      %h4= p.title

它会给你

<div class="movie effect>...</div>
<div class="movie effect>...</div>
<div class="movie effect>...</div>
<div class="movie effect>...</div>
<div class="movie effect>...</div>
<div class="movie effect>...</div>

如何让它为每 3 个 div 应用“最后一个”类。例如：

<div class="movie effect>...</div>
<div class="movie effect>...</div>
<div class="movie effect last>...</div>
<div class="movie effect>...</div>
<div class="movie effect>...</div>
<div class="movie effect last>...</div>

Answer 1

你可以使用cycle方法：

.movie.effect{class: cycle('', '', 'last')}