sbt10 - generated sources

gistfile1.scala

import sbt._
import sbt.Keys._

object build extends Build {
  lazy val generate = Project(
    id        = "source-gen",
    base      = file("."),
    settings  = Defaults.defaultSettings ++ generateSourceSettings
  )  
  
  lazy val GenSourcesConfig = config("gen-sources-config").hide
  lazy val genSources = TaskKey[Seq[File]]("gen-src")
  lazy val outputDir = SettingKey[File]("output-dir")

  lazy val generateSourceSettings: Seq[Project.Setting[_]] = inConfig(GenSourcesConfig)(Seq(
    genSources <<= genSourcesTask,
	outputDir <<= (sourceDirectory in Compile) {_ / "src_managed"},
    (managedSourceDirectories in Compile) <+= (outputDir in GenSourcesConfig).identity
  ))++ Seq(sourceGenerators in Compile <+= (genSources in GenSourcesConfig).identity)

  def genSourcesTask = (streams, outputDir in GenSourcesConfig) map ((s, dir) => {
    s.log.info("generating java sources")
    val source = "package javapackage;\n\n" +
                 "public class GeneratedJavaClass {\n\n public String theString;\n}\n"
     val outputFile = (dir / "GeneratedJavaClass.java").asFile
	 IO.write(outputFile, source)
         //Seq(outputFile) in case you generate directly
	 (dir ** "*.java").get //in case your files are generated by an external process
  })
}