...
import scalafui.FunctionalUI._

object Main {

  //
  // MODEL
  //

  case class Model(messages: Seq[String] = Seq.empty, input: String = "")

  def init(url: URL): (Model, Seq[Cmd[Msg]]) = (Model(), Seq.empty)

  //
  // UPDATE
  //

  sealed trait Msg
  case class Input(input: String) extends Msg
  case object Send extends Msg

  def update(msg: Msg, model: Model): (Model, Seq[Cmd[Msg]]) =
    msg match {
      case Input(input) =>
        (model.copy(input = input), Seq.empty)

      case Send =>
        (
          model.copy(messages = model.messages :+ model.input, input = ""),
          Seq.empty
        )
    }

  //
  // VIEW
  //

  def view(model: Model, dispatch: Msg => Unit): ReactElement =
    div(
      h1("Welcome to Functional UI!"),
      div(className := "message-input")(
        input(
          value := model.input,
          onInput := (e => dispatch(Input(e.target.value)))
        ),
        button(onClick := (e => dispatch(Send)))("Send")
      ),
      div(className := "messages")(
        model.messages.map(div(className := "message")(_))
      )
    )

  def main(args: Array[String]): Unit = {
    if (LinkingInfo.developmentMode) {
      hot.initialize()
    }

    Browser.runProgram(
      dom.document.getElementById("app"),
      Program(init, view, update)
    )
  }
}