Call sourceGenerators manually in sbt

Question

I am using sourceGenerators in Compile to generate some Scala source files to target\scala-2.10\src_managed. When I run sbt compilethe sources are generated and compiled along with the regular code under src\main\scala.

But what if I want to generate the sources separately without compiling? What I am looking for is this flow:

1. call a task to generate source code
2. use the generated sources for IDE assistance in my regular sources
3. compile everything

How can this be accomplished?

Answer 1

Update

If I got you correct now, you want to be able to call the source generators seperately. For that you can simply define a custom task like this somewhere in your /build.sbt or /project/Project.scala file:

val generateSources = taskKey[List[File]]("generate sources")

generateSources <<= 
  (sourceGenerators in Compile) { _.join.map(_.flatten.toList) }

you can then call the generator manually from the sbt console like this:

> generateSources
[success] Total time: 0 s, completed 07.04.2014 13:42:41

Side Note: I would however reccomend to setup your IDE to generate the sources if the only thing you need them for is to get IDE support.

---

Old answer for future reference

You don't need to do anything special to use a generated class or object from a non-generated class or object.

In your /build.sbt or /project/Project.scala file you define the source generator:

sourceGenerators in Compile <+= sourceManaged in Compile map { dir =>
  val file = dir / "A.scala"
  IO.write(file, "class A(val name: String)")
  Seq(file)
}

Then you write some code which creates an instance of class A in/src/main/scala/B.scala:

object B extends App {
  val a = new A("It works")
  println(a.name)
}

If you compile this code from sbt, it will consider both generated and non-generated code at compilation:

> run
[info] Compiling 2 scala sources to <...>
[info] Running B
It works
[success] Total time: 0 s, completed 07.04.2014 13:15:47