class Kramdown::Converter::Kramdown

def ial_for_element(el)
  res = el.attr.map do |k,v|
    next if [:img, :a].include?(el.type) && ['href', 'src', 'alt', 'title'].include?(k)
    next if el.type == :header && k == 'id'
    if v.nil?
      ''
    elsif k == 'class'
      " " + v.split(/\s+/).map {|w| ".#{w}"}.join(" ")
    elsif k == 'id'
      " ##{v}"
    else
      " #{k}=\"#{v.to_s}\""
    end
  end.compact.join('')
  res = "toc" + (res.strip.empty? ? '' : " #{res}") if (el.type == :ul || el.type == :ol) &&
    (el.options[:ial][:refs].include?('toc') rescue nil)
  res.strip.empty? ? nil : "{:#{res}}"
end