DataMapper Test

script.rb

require 'dm-core'
require 'dm-migrations'
require 'dm-serializer'

DataMapper::Logger.new($stdout, :debug)
DataMapper.setup(:default, 'sqlite:test.sqlite')

# =========================================
# MODEL
# =========================================

class Device
  include DataMapper::Resource
  
  property :id,     Serial
  property :udid,   String,   :required => true
  
  has n, :apps, :through => Resource
end

class App
  include DataMapper::Resource
  
  property :id,         Serial
  property :bundle_id,  String,   :required => true
  
  has n, :devices, :through => Resource
  
  def to_json(*args)
    json_hash = { "bundle_id" => bundle_id }
    
    if args.first[:deep] then
      json_hash["devices"] = devices.to_json(*args)
    end
    
    json_hash.to_json(*args)
  end

  def self.json_create(object)
    new(*object)
  end
end

DataMapper.finalize
DataMapper.auto_upgrade!

# =========================================
# TEST
# =========================================

Device.first_or_create(:udid => 'd1')
Device.first_or_create(:udid => 'd2')
Device.first_or_create(:udid => 'd3')
Device.first_or_create(:udid => 'd4')
Device.first_or_create(:udid => 'd5')
Device.first_or_create(:udid => 'd6')

app = App.first_or_create(:bundle_id => 'a')

udids = ['d2', 'd4', 'd6']
app.update(:devices => udids.map {|udid| Device.first_or_create(:udid => udid) })
puts app.devices

puts "Device.all(:apps => nil) = #{Device.all(:apps => nil).inspect}"
puts "Device.all(:apps => []) = #{Device.all(:apps => []).inspect}"