EnginePlugin

val engine = PolyglotEngine {
 // install support for specific languages
 install(JavaScript) {
   esm = true

   intrinsics {
     console()
     base64()
     json()
   }
 }
}

// This class is used for instances of the plugin
class MyPlugin(private val config: MyConfig) {
 // A custom configuration class than defines this plugin's DSL
 class MyConfig {
   var message: String = "Hello"
 }

 // a simple function to be called from the engine creation event listener
 fun greetEngine() {
   println(config.message)
 }

 // a simple function to be called from the context creation event listener
 fun greetContext() {
   println(config.message)
 }

 // The companion object is used as plugin identifier
 companion object : EnginePlugin<MyConfig, MyPlugin> {
   // This key will identify the plugin in the registry
   override val key = Key("MyPlugin")

   // This event will be called by the DSL to obtain the plugin instance that
   // will be added to the plugin registry
   override fun install(
     scope: InstallationScope,
     configuration: Config.() -> Unit
   ): Instance {
     // we receive the DSL function, so we can instantiate the configuration
     // class as needed, don't forget to apply the user configuration!
     val config = MyConfig().apply(configuration)

     // now we create the plugin instance that will live in the engine
     val instance = MyPlugin(config)

     // we can subscribe to lifecycle events using the installation scope
     scope.lifecycle.on(EngineCreated) { instance.greetEngine() }
     scope.lifecycle.on(ContextCreated) { instance.greetContext() }

     // it is also possible to detect and install other plugins in the scope
     scope.configuration.plugin(OtherPlugin)?.let {
       println("OtherPlugin is installed")
     }

     // finally, we return the instance
     return instance
   }
 }
}