Can I use sbt's `apiMappings` setting for managed dependencies?

Question

I\'d like the ScalaDoc I generate with sbt to link to external libraries, and in sbt 0.13 we have autoAPIMappings which is supposed to add these links for libra

Answer 1

The accepted answer is good, but it'll fail when assumptions about exact project dependencies don't hold. Here's a variation that might prove useful:

apiMappings ++= {
  def mappingsFor(organization: String, names: List[String], location: String, revision: (String) => String = identity): Seq[(File, URL)] =
    for {
      entry: Attributed[File] <- (fullClasspath in Compile).value
      module: ModuleID <- entry.get(moduleID.key)
      if module.organization == organization
      if names.exists(module.name.startsWith)
    } yield entry.data -> url(location.format(revision(module.revision)))

  val mappings: Seq[(File, URL)] =
    mappingsFor("org.scala-lang", List("scala-library"), "http://scala-lang.org/api/%s/") ++
      mappingsFor("com.typesafe.akka", List("akka-actor"), "http://doc.akka.io/api/akka/%s/") ++
      mappingsFor("com.typesafe.play", List("play-iteratees", "play-json"), "http://playframework.com/documentation/%s/api/scala/index.html", _.replaceAll("[\\d]$", "x"))

  mappings.toMap
}

(Including scala-library here is redundant, but useful for illustration purposes.)

If you perform mappings foreach println, you'll get output like (note that I don't have Akka in my dependencies):

(/Users/michaelahlers/.ivy2/cache/org.scala-lang/scala-library/jars/scala-library-2.11.7.jar,http://scala-lang.org/api/2.11.7/)
(/Users/michaelahlers/.ivy2/cache/com.typesafe.play/play-iteratees_2.11/jars/play-iteratees_2.11-2.4.6.jar,http://playframework.com/documentation/2.4.x/api/scala/)
(/Users/michaelahlers/.ivy2/cache/com.typesafe.play/play-json_2.11/jars/play-json_2.11-2.4.6.jar,http://playframework.com/documentation/2.4.x/api/scala/)

This approach:

1. Allows for none or many matches to the module identifier.
2. Concisely supports multiple modules to link the same documentation.
   • Or, with Nil provided to names, all modules for an organization.
3. Defers to the module as the version authority.
   • But lets you map over versions as needed.
     • As in the case with Play's libraries, where x is used for the patch number.

Those improvements allow you to create a separate SBT file (call it scaladocMappings.sbt) that can be maintained in a single location and easily copy and pasted into any project.