ruby – 嵌套两个具有可选参数的自定义Liquid标签

给出以下ruby代码,源自Octopress(一个jekyll fork),它创建一个自定义Liquid标签来解析标签.

# Title: Simple Image tag for Jekyll
# Authors: Brandon Mathis http://brandonmathis.com
#          Felix Sch?fer,Frederic Hemberger
# Description: Easily output images with optional class names,width,height,title and alt attributes
#
# Syntax {% img [class name(s)] [http[s]:/]/path/to/image [width [height]] [title text | "title text" ["alt text"]] %}
#
# Examples:
# {% img /images/ninja.png Ninja Attack! %}
# {% img left half http://site.com/images/ninja.png Ninja Attack! %}
# {% img left half http://site.com/images/ninja.png 150 150 "Ninja Attack!" "Ninja in attack posture" %}
#
# Output:
# <img src="/images/ninja.png">
# <img class="left half" src="http://site.com/images/ninja.png" title="Ninja Attack!" alt="Ninja Attack!">
# <img class="left half" src="http://site.com/images/ninja.png" width="150" height="150" title="Ninja Attack!" alt="Ninja in attack posture">
#

module Jekyll

class ImageTag < Liquid::Tag
  @img = nil

  def initialize(tag_name,markup,tokens)
    attributes = ['class','src','width','height','title']

    if markup =~ /(?<class>S.*s+)?(?<src>(?:https?://|/|S+/)S+)(?:s+(?<width>d+))?(?:s+(?<height>d+))?(?<title>s+.+)?/i
      @img = attributes.reduce({}) { |img,attr| img[attr] = $~[attr].strip if $~[attr]; img }
      if /(?:"|')(?<title>[^"']+)?(?:"|')s+(?:"|')(?<alt>[^"']+)?(?:"|')/ =~ @img['title']
        @img['title']  = title
        @img['alt']    = alt
      else
        @img['alt']    = @img['title'].gsub!(/"/,'&#34;') if @img['title']
      end
      @img['class'].gsub!(/"/,'') if @img['class']
    end
    super
  end

  def render(context)
    if @img
      "<img #{@img.collect {|k,v| "#{k}="#{v}"" if v}.join(" ")}>"
    else
      "Error processing input,expected syntax: {% img [class name(s)] [http[s]:/]/path/to/image [width [height]] [title text | "title text" ["alt text"]] %}"
    end
  end
end
end
Liquid::Template.register_tag('img',Jekyll::ImageTag)

创建另一个自定义标记的最佳方法是为[< img>]元素展示相同的功能,但嵌套在[< figure>]元素中,并且可能将图像alt描述或附加标记显示为[ < figcaption>]元素可能包含自己的链接？或者甚至可能是元素的一系列类名,表明它是否应该居中.

换句话说,我可能希望输出类似于：

<figure class=center>
  <img src="/contra.jpg" alt="One of the greatest nintendo games of all time">
  <figcaption>Up Up Down Down Left Right Left Right B A B A <a href="http://www.youtube.com/contramoves/">Watch on Youtube</a></figcaption>
</figure>

我错误地认为可以嵌套自定义Liquid标签吗？我确信我可以再次重写现有代码并稍微修改它以处理[< figcaption>]的附加属性,但这似乎相当多余并且违反DRY原则.就目前的情况而言,考虑到现有的类本身采用可选的令牌,我对如何考虑可能的附加令牌感到困惑.