gistfile1.rb

require 'nokogiri'

class HTMLPage < Nanoc3::Filter
  identifier :htmlpage
  type :text

  def run(content, params={})
    page = Nokogiri::HTML(content)

    begin
      @item[:title] = page.at('//title').content
    rescue NoMethodError
      @item[:title] = File.basename(@item[:filename], File.extname(@item[:filename]))
    end

    begin
      @item[:description] = page.at("//meta[@name='description']")['content']
    rescue NoMethodError
      #pass
    end

    @item[:menu] = Menu.new(@item[:filename])

    return page.at('//body').children.to_s
  end
end


require 'nokogiri'

class Menu
  def initialize(filename)
    @filename = filename.gsub(/^content\//, '')

    @level = nil
    @path = nil

    if File.exists?('content/sitemap.html')
      sitemap = Nokogiri::HTML(open('content/sitemap.html'))

      sitemap.xpath("//a[@href='#{@filename}']").each {|a|
        level = a.path.split('/ul/').size - 1
        if @level.nil? || level > @level
          @level = level
          @path = a.path
        end
      }
    end

    @cache = {}
  end

  def menu(start, levels=nil)
    return nil unless @path

    # levels below start
    maxlevels = @level - start + 1
    levels ||= maxlevels
    levels = maxlevels if levels > maxlevels

    return nil if levels == 0

    key = "#{start}-#{levels}"

    if @cache[key].nil?
      sitemap = Nokogiri::HTML(open('content/sitemap.html'))

      # mark selected path
      path = @path.gsub(/\/a$/, '/').split('/')
      path.each_with_index{|elt, i|

        sitemap.at(path[0 .. i].join('/'))['class'] = 'selected' if elt =~ /li/
      }

      # skip levels above start
      path = @path.gsub(/\/li(\[[0-9]+\])?\/a$/, '/')
      path = path.split('/ul/')[0,start].join('/ul/') + '/ul'
      m = sitemap.xpath(path)

      # prune unwanted levels
      path = './/' + (['ul'] * (levels)).join('//')
      m.xpath(path).remove

      # fix links
      m.xpath('.//a').each {|a|
        next if a['href'] =~ /^http/ || a['href'] =~ /^\//
        a['href'] = Pathname.new(a['href']).relative_path_from(Pathname.new(File.dirname(@filename)))
      }

      @cache[key] = m.to_s
    end

    return @cache[key]
  end
end