Jekyll - Custom post_file_link tag plugin

jekyll-post-file-link-tag.rb

# Jekyll - Custom post_file_link tag plugin. Points to /files/:title/FILE.ext
#
# How to install: Drop this file in `_plugins`.
# How to use: `{% post_file_link FILENAME.EXT %}`

module Jekyll
  class RenderPostFileLinkTag < Liquid::Tag

    def initialize(tag_name, text, tokens)
      super
      @text = text
    end

    def lookup(context, name)
      lookup = context
      name.split(".").each { |value| lookup = lookup[value] }
      lookup
    end

    def render(context)
      path  = "#{lookup(context, 'site.baseurl')}/files/"
      path += "#{lookup(context, 'page.path')}".split('/').last.chomp('.md')
      "#{path}/#{@text}"
    end
  end
end

Liquid::Template.register_tag('post_file_link', Jekyll::RenderPostFileLinkTag)

# Alternate tag name.
Liquid::Template.register_tag('post_file_url', Jekyll::RenderPostFileLinkTag)