RawDynamicTranslationBinding.scala

class RawDynamicTranslationBinding[Key <: TranslationKey](
  key: Key,
  translator: Key => Future[Translated],
  placeholder: Option[Element]
)(implicit lang: ReadableProperty[Lang]) extends Binding with CrossLogging {

  override def applyTo(t: Element): Unit = {
    var holder = Seq(placeholder.getOrElse(emptyStringNode()))
    holder.foreach(t.appendChild)

    def rebuild(): Unit = {
      translator(key).onCompleteNow {
        case Success(text) =>
          val wrapper = document.createElement("div")
          wrapper.innerHTML = text.string
          val newHolder = wrapper.childNodes match {
            case kids if kids.length == 0 =>
              Seq(placeholder.getOrElse(emptyStringNode()))
            case kids =>
              (0 until kids.length).map(kids(_))
          }
          newHolder.foreach(t.insertBefore(_, holder.head))
          holder.foreach(t.removeChild)
          holder = newHolder
        case Failure(ex) =>
          logger.error(ex.getMessage)
      }
    }

    propertyListeners += lang.listen(_ => rebuild(), initUpdate = true)
  }

}