Script that uses nokogiri and data-mapper to fetch and store data from my posts in PijamaSurf

pijama.rb

# encoding: utf-8
require 'rubygems'
require 'nokogiri' 
require 'open-uri'
require 'data_mapper'
require 'dm-sqlite-adapter'
require 'date'
require 'set'
require 'json'

DataMapper.setup(:default, "sqlite3://#{Dir.pwd}/pijama.db")
class Post
  include DataMapper::Resource
  property :id, Serial
  property :name, String, :length => 140
  property :url, String, :length => 140
  property :date,  Date
  property :words, Integer
  property :visits, Integer
  property :comments, Integer
  property :twitter, Integer
  property :facebook, Integer
end
DataMapper.auto_upgrade!

def facebook_likes(url)
    data = open("http://graph.facebook.com/?ids=#{URI.escape(url)}").read
    data = JSON.parse(data)
    data[url]['shares']
end

def twitter_shares(url)
    data = open("http://urls.api.twitter.com/1/urls/count.json?url=#{URI.escape(url)}").read
    data = JSON.parse(data)
    data['count']
end

URL = 'http://pijamasurf.com/author/federico-erostarbe/'

urls = Set.new
base = Nokogiri::HTML(open(URL))
data = base.at_css("#search-list").children().children()       
data.each do |node|
    attrs = node.attributes
    if attrs.member?('href')
        urls << attrs['href'].content
    end
end
urls.each do |url|
    post = Post.first(:url => url)
    flag = true
    if post.nil?
        flag = false
    end
    post_base = Nokogiri::HTML(open(url))
    post_data = post_base.at_css('#post-info')
    info = post_data.children.children
    if !flag
        content_set = post_base.at_css('.post-content').children
        text = ""
        content_set.each do |t|
            if !(t.content.start_with?('Twitter del autor') || t.content.start_with?('También en Pijama Surf'))
                text += t.content
            end
        end
        string_date = post_base.css('.post-above').to_xml(:indent => 5, :encoding => 'UTF-8')[/\d{2}\/\d{2}\/\d{4}/]
        name = post_base.css('title').children.first.content.split(' | ').first
        post = Post.new
        post.name = name
        post.date = Date::strptime(string_date, '%d/%m/%Y')
        post.url = url
        post.words = text.split.size
    end
    comments = post_base.css('#comments-count').children.first.content.split(' ').first.to_i
    if comments == 0 && post_base.css('#comments-count').children.first.content.start_with?('Un ') 
        comments = 1 
    end
    visits = info.first.content.split(' | ').last.to_i
    post.twitter = twitter_shares url
    post.facebook = facebook_likes url
    post.comments = comments
    post.visits = visits
    post.save
end