ExportScalaToJS.scala

// -----------------------------------------------
// scalaJS 로 스칼라 오브젝트, 클래스, 메소드 등을
// JS 로 내보내기 예제
// ------------------------------------------------

import js.annotation.JSExport
import js.annotation.JSExportNamed
import js.annotation.JSExportAll
import scala.annotation.meta.field
import js.annotation.JSExportDescendentObjects

// ScalaJSExample().main() 으로 호출
// 자바스크립트에서는 함수로 내보내진다.
// 외부에서 호출되려면 최소 하나의
// 클래스나 오브젝트와 메소드가 내보내져야 함.

@JSExport("app")
object ScalaJSExample extends js.JSApp{
  
  @JSExportNamed
  def bar(first:String, last:String) : Unit = println(""+ first + last)
  
  @JSExportNamed
  def foo(x: Int, y: Int = 2, z: Int = 3) = x+y+z
  
  @JSExport
  def main(): Unit = {
    println("hello");
  }
}


@JSExport
class Mine(val x: Int){
  
  @JSExport
  def add(y:Int) : Int = x+y
  
  @JSExport
  def add(y:Int, z:Int) : Int = x+y+z
  
}

@JSExport
class Point(ex: Double, why: Double) {
  @JSExport
  val x: Double = ex
  @JSExport
  var y: Double = why
  @JSExport
  def abs: Double = Math.sqrt(x*x + y*y)
  @JSExport
  def sum: Double = x + y
  @JSExport
  def sum_=(v: Double): Unit = y = v - x
  @JSExport
  def name_=(v: Double):Unit = y = v - x
}

@JSExport
class Loint(
    @(JSExport @field) val x: Double,
    @(JSExport @field) val y: Double){
      
      @JSExport
      def loAdd = x+y
    }

// Also applies to case classes
@JSExport
case class Voint(
    @(JSExport @field) x: Double,
    @(JSExport @field) y: Double){
      
      @JSExport
      def voAdd = x+y
    }

@JSExportDescendentObjects
trait Test {
  @JSExport
  def test(param: String):Unit
}

// automatically exported as foo.test.Test1
object Test1 extends Test {
  // exported through inheritance
  def test(param: String) = {
    println(param)
  }
}

class Parent {
  def pDef(x: Int, y: Int): Int = x * y
}

@JSExport
@JSExportAll
class Child(val a: Int) extends Parent {
  override def pDef(x: Int, y: Int): Int = x * y
  def cDef(x: Int, y: Int): Int = x + y
}

// @JSExport 와 @JSExportAll 을 함께 써야 하는지 따로 써야 하는지에 관한 답변
// https://github.com/scala-js/scala-js/issues/1476
// 
//    @JSExport exports the object itself (or the class' constructor, if it is a class)
//    @JSExportAll exports all its members, but not the object/constructor itself.
//