require 'data_mapper'

DataMapper.setup(:default, "sqlite::memory:")

class Post
  include DataMapper::Resource
  property :id, Serial
  property :title, String
  after :create do
    self.title = "The id is #{id}"
    save
  end
end

DataMapper.finalize
DataMapper.auto_migrate!

post = Post.new
if post.save
  puts 'Successfully saved.'
else
  puts "Errors: #{post.errors.size}"
end
p DataMapper::VERSION, post, post.title

# called with 'ruby -rubygems saveaftercreate.rb' outputs:
# Errors: 0
# "1.1.0"
# #<Post @id=1 @title="The id is 1">
# "The id is 1"