data_mapper configuration for Sinatra (over Rack) web app

myBlog.rb

require 'sinatra/base'
require 'sinatra/json'
require 'data_mapper'

#If you want the logs displayed you have to do this before the call to setup
DataMapper::Logger.new($stdout, :debug)

#Set the default lenght of String
DataMapper::Property::String.length(255)

#Raise error when save fails
DataMapper::Model.raise_on_save_failure = true

#Setup the DB
DataMapper::setup(:default, "sqlite3://#{Dir.pwd}/blog.db")

class Post
  include DataMapper::Resource

  property :id, 			Serial    # An auto-increment integer key
  property :title, 			String
  property :subtitle, 		String
  property :content, 		Text
  property :created_at, 	DateTime
  property :updated_at,		DateTime
end

DataMapper.finalize
Post.auto_upgrade!

class MyBlog < Sinatra::Base
...
end