TimeStamped.scala

import _root_.net.liftweb.mapper._

trait HasCreatedMetaMapper[T <: HasCreated[T]] {
  self: T with LongKeyedMetaMapper[T] =>
  import java.util.Date
  def findByCreated(startDate:Date, endDate:Date) = findAll(By_>(created_at, startDate), By_<(created_at, endDate))
  def findByCreatedSince(startDate: Date) = findAll(By_>(created_at, startDate))
}

trait HasCreated [T <: HasCreated[T]] extends KeyedMapper[Long, T] {
  self: T => 
  object created_at extends MappedTimestamp(this)
  
  class MappedTimestamp[T<:Mapper[T]](override val fieldOwner: T) extends MappedDateTime[T](fieldOwner) {
    override def dbDisplay_? = false
    override def writePermission_? = false
    override def defaultValue = new java.util.Date();
    def _secureUpdate() = {
      i_set_!(new java.util.Date())
    }
  }
  
}

trait TimeStamped [T <: TimeStamped[T]] extends HasCreated[T]{
  self: T => 
  
  object updated_at extends MappedTimestamp(this)
  
  override def save():Boolean = {
    if (dirty_?)
      updated_at._secureUpdate
    super.save()
  }
}