New name!

Use Scala Stack JS Compiler instead. It's the same repository but with a new name. Link https://github.com/AIMMOTH/scala-stack-js-compiler

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Scala JS Compiler

Compiles list of Strings with Scala JS code to a JavaScript.

Environment

This is a SBT project with Java 21, Scala 3.3.1 and Scala JS 1.12.0

Using it

Class ScalaJsCompiler uses method init to create Classpath with all necessary libraries loaded.

Build it

Use SBT to build a library. You can use > sbt publishM2 to create a local Maven library.

Simple Example using Servlet API

This compiler is excellent to use for a backend server compiling JavaScript on request!

    @WebListener
    class WebServletContextListener extends ServletContextListener {
    
        val scalaJsCode =
            """
              |package tutorial.webapp
              |
              |object TutorialApp {
              |  def main(args: Array[String]): Unit = {
              |    println("Hello world!")
              |  }
              |}
              |""".stripMargin
              
        def contextInitialized(contextEvent: ServletContextEvent): Unit = {
            val loader: (String => InputStream) = (path) => contextEvent.getServletContext.getResourceAsStream(path)
            
            val compiler = ScalaJsCompiler()
            val classpath = compiler.init(loader, "/WEB-INF/lib/", Set("scala3-library_3-3.3.1.jar", "scala-library-2.13.10.jar", "scalajs-javalib-1.12.0.jar", "scalajs-library_2.13-1.12.0.jar"))
            val javascript = compiler.compileScalaJsString(classpath, scalaJsFile, Optimizer.Fast)
        }
    }

This is reading JAR-files in WEB-INF/lib and provided ScalaJS source. One trick is to put all ScalaJS source in /src/main/webapp/ to make it available for the Servlet context.

Contributions

Thanks to VirtusLab for upgrading this library!