如何在HAML中构建嵌套菜单"树"

Question

我正在尝试使用HAML构建一个简单的嵌套html菜单,并且不确定如何使用正确的缩进插入元素,或者是构建嵌套树的一般最佳方法.我希望能够做到这样的事情,但无限深入:

- categories.each_key do |category|
    %li.cat-item{:id => "category-#{category}"}
        %a{:href => "/category/#{category}", :title => "#{category.titleize}"}
            = category.titleize

感觉我应该能够很容易地完成这个,而不需要在html中手工编写标签,但我不是最好的递归.这是我目前提出的代码:

查看助手

def menu_tag_builder(array, &block)
  return "" if array.nil?
  result = "<ul>\n"
  array.each do |node|
    result += "<li"
    attributes = {}
    if block_given?
      text = yield(attributes, node)
    else
      text = node["title"]
    end
    attributes.each { |k,v| result += " #{k.to_s}='#{v.to_s}'"}
    result += ">\n"
    result += text
    result += menu_tag_builder(node["children"], &block)
    result += "</li>\n"
  end
  result += "</ul>"
  result
end

def menu_tag(array, &block)
  haml_concat(menu_tag_builder(array, &block))
end

视图

# index.haml, where config(:menu) converts the yaml below
# to an array of objects, where object[:children] is a nested array
- menu_tag(config(:menu)) do |attributes, node|
 - attributes[:class] = "one two"
 - node["title"]

示例YAML定义菜单

menu:
  -
    title: "Home"
    path: "/home"
  -
    title: "About Us"
    path: "/about"
    children: 
      -
        title: "Our Story"
        path: "/about/our-story"

任何想法如何做到这样输出是这样的:

<ul>
  <li class='one two'>
    Home
  </li>
  <li class='one two'>
    About Us
  </li>
</ul>

......不是这样的:

<ul>
<li class='one two'>
Home</li>
<li class='one two'>
About Us</li>
</ul>

......所以它在全球范围内正确缩进.

谢谢你的帮助,兰斯

Answer 1

很好地缩进,Ruby生成的Haml代码的技巧就是haml_tag帮手.以下是我将您的menu_tag方法转换为使用方法的方法haml_tag:

def menu_tag(array, &block)
  return unless array
  haml_tag :ul do
    array.each do |node|
      attributes = {}
      if block_given?
        text = yield(attributes, node)
      else
        text = node["title"]
      end
      haml_tag :li, text, attributes
      menu_tag_builder(node["children"], &block)
    end
  end
end