A nanoc helper for extracting blog post summaries through a <!--READMORE--> marker

nanoc_blog_excerpt.rb

require 'rubygems'
require 'nokogiri'
module Helpers
 def blog_excerpt(item, read_more='<!--READMORE-->')
    post_dom = Nokogiri::HTML::DocumentFragment.parse(item.compiled_content)
    more_tag_found = false

    post_dom.css('*').each do |p, index|
      if p.inner_html.match(read_more)
        p.inner_html = p.inner_html.gsub(Regexp.new("#{read_more}.*"), "&nbsp; <a href=\"#{item.identifier}\" title=\"#{item[:title]}\" class=\"read-more\">Read more...</a>")
        more_tag_found = true
        next
      end
      p.remove if more_tag_found
    end

    more_tag_found ?
      post_dom.to_s :
      item.compiled_content
  end
end