Dependency injection with Lift

While migrating my web app to Lift 2.2 and CSS selectors i've noticed the dependency injection section in Simply Lift. It looked interesting and i decided to try it. Here is what i've finally got:

The Factory:

object DependencyFactory extends Factory {
  // The following trait has become necessary to avoid name clashes 
  // between a FactoryMaker and its contents during implicit conversion
  // (e.g. FactoryMaker has method 'find' so if contained type has a 
  // 'find' too it will not trigger the implicit conversion and you'll
  // get error instead)
  trait VendorMarker[T] {
    this: FactoryMaker[T] =>
    // since our fields will be visible as Vendor (to avoid name clashes),
    // we need a method to get back to FactoryMaker (e.g. to use its 
    // 'doWith' method)
    def asFactoryMaker: FactoryMaker[T] = this
  }
  // factory method to make FactoryMakers visible as Vendors with a 
  // marker trait
  private def newVendor[T : Manifest](v: T): Vendor[T] with VendorMarker[T] =
    new FactoryMaker[T](v) with VendorMarker[T]

  implicit def vendorToValue[T](vendor: Vendor[T]): T = vendor.vend

  val props = newVendor[AppProperties](new AppPropertiesImpl)
  val db = newVendor[DbAccess](Model)
  val roomStore = newVendor(new RoomStore)
  val quizFactory = newVendor(new QuizFactory)
  // etc
}

Usage examples:

class RoomStore {
  // Dependency requirements expressed with imports
  import lib.DependencyFactory.db

  // now we are using db as DbAccess via the implicit conversion
  def updateRoom(room: Room): Room = db.merge(room)
  def getRoom(id: Long): Option[Room] = db.find(classOf[Room], id)
}

// This one has a lot of dependencies
import lib.DependencyFactory.{chatFactory, currentTime, roomStore, persistentMessageStore, questionStore}
class Quiz(_room: Room) extends AbstractQuiz(chatFactory.newChat(), currentTime) {
// ...
}

class QuizFactory {
  def newQuiz(room: Room) = new Quiz(room)
  // note the asFactoryMaker.doWith usage to temporarily replace a dependency
  def newQuiz(room: Room, msgs: List[Message]) =
    lib.DependencyFactory.chatFactory.asFactoryMaker.doWith(new ChatFactory {
        override def newChat(msgs: List[Message], capacity: Int) = new Chat(msgs, 100)
      }) { new Quiz(room) }
}

Quite cool feature to use!