Facebook.rb

require 'rubygems'
require 'digest/md5'
require 'json'
require 'net/http'

class Facebook
  public

  # This is it.
  def self.callMethod(methodName, args={})
    args ||= {}
    args.each_pair {|key, value| args[key] = jsonify(value) }

    args['v'] = '1.0'
    args['format'] = 'JSON'
    args['method'] = methodName
    args['api_key'] = @@apiKey
    args['session_key'] = @@sessionKey
    args['call_id'] = (@@call_id += 1)
    args['ss'] = true
    hashString = args.keys.sort.map{|key|
      "#{key}=#{args[key]}"}.push(@@sessionSecret).join
    args['sig'] = Digest::MD5.hexdigest(hashString)
    res = Net::HTTP.post_form(
      URI.parse('http://api.facebook.com/restserver.php'),
      args)
    JSON.parse(res.body.to_s)
  end

  @@apiKey = '39f0aec9479177cddacef90da714b037'
  @@sessionKey = '2.xGrvqiHmJ3b_DKX2LmGjgA__.86400.1247101200-688626964'
  @@sessionSecret = 'O0iifghAyr_Ylb5D9FCDWg__'
  @@call_id = Time.now.tv_sec

  private

  def self.jsonify(item)
    if (item.class == Hash)
      item.each_pair {|key, value|
        item[key] = jsonify(value)
      }
      item.to_json
    elsif (item.class == Array)
      item.map{|entry| jsonify(entry)}.to_json
    else
      item
    end
  end
end

# Some examples...

# Get all my friend ids
friend_ids = Facebook::callMethod("friends.get")

# Get some info about my friends, and print it out
friend_data = Facebook::callMethod("fql.query", {
  'query' => "select name, status from user " +
    "where uid in (#{friend_ids.join(',')})"
})
friend_data.each {|friend|
  puts "Name: #{friend['name']}"
  # Avoid NIL error when there's no status ever set, ever.
  if (friend['status'])
    puts "Status: #{friend['status']['message']}"
  end
}