dynmap-players.rb

#!/usr/bin/env ruby

# require "headless"
require "capybara"
require "capybara-webkit"

class Capybara::Session
  def wait_css(selector, timeout_sec = 5)
    timeout_sec.times do
      break if has_css?(selector)
      sleep 1
    end
  end
end

class DynMap
  def initialize(url)
    @url = url
    Capybara.javascript_driver = :webkit
    @session = Capybara::Session.new(:webkit)
  end

  def players
    @session.visit(@url)
    @session.wait_css(".playerlist .player")
    @session.all(:css, ".playerlist .player").map(&:text)
  end
end

# Headless.new.start

dynmap = DynMap.new("http://example.com:8123/")
p dynmap.players # => ["user1", "user2"]