gistfile1.rb

require 'rubygems'
require 'scrubyt'
require 'nokogiri'
require 'iconv'

# Fetch the seatplan for the schedule
movies = Scrubyt::Extractor.define do
  # use a proper schedule link here
  fetch "http://www2.cinema.com.hk/revamp/html/show_seat.php?lang=c&show_id=13105241"

  # schedule info
  schedule "//table[2]" do
    cinema  "//tr[1]/td[2]"
    house   "//tr[2]/td[2]"
    movie   "//tr[3]/td[2]"
    cat     "//tr[4]/td[2]"
    time    "//tr[5]/td[2]"    
  end
  
  # seats info
  seatplan  "//body"  do
    row "//table//table//table//table//table//table//table//tr" do
      label("//td[@class='seat_C']").select_indices(:first)
      seat "//td[@class='seat_A']"
    end
  end
end

# count how many seats available, insert it into result, and remove seatplan details
result = Nokogiri::XML(movies.to_xml, nil, "BIG-5")
(result/"//seatplan").each do |seatplan|
  seats = Nokogiri::XML::Element.new("seats", seatplan.document)
  seats.content = (seatplan/"//seat").size

  (result/"//schedule").each do |schedule|
    schedule.add_child(seats)
  end
  seatplan.unlink
end
puts result.to_s