Unzipping an artifact with SBT - sbt

Question

As part of my project build, I'd like to unzip a zip artifact of a managed dependency into a specific directory of the project. Before starting to use SBT I was doing this via an ANT script that would fetch the zip artifact from a maven dependency and unzip it.
My question(s) are:
how to specify that I want to depend on the zip dependency? I have defined it like so:
"eu.delving" % "sip-creator" % "0.4.6-SNAPSHOT"
but this doesn't fetch the zip artifact
where / how to hook into the build process to run the unzip (and how to refer to the artifact file in that context)?

Answer 1

If you want to extract a set of managed dependencies, the code below should work. I tested it in sbt 0.12.0, but it should also work with 0.11.x.
import sbt._
import Keys._
import Classpaths.managedJars
object TestBuild extends Build {
lazy val jarsToExtract = TaskKey[Seq[File]]("jars-to-extract", "JAR files to be extracted")
lazy val extractJarsTarget = SettingKey[File]("extract-jars-target", "Target directory for extracted JAR files")
lazy val extractJars = TaskKey[Unit]("extract-jars", "Extracts JAR files")
lazy val testSettings = Defaults.defaultSettings ++ Seq(
// define dependencies
libraryDependencies ++= Seq(
"com.newrelic" % "newrelic-api" % "2.2.1"
),
// collect jar files to be extracted from managed jar dependencies
jarsToExtract <<= (classpathTypes, update) map { (ct, up) =>
managedJars(Compile, ct, up) map { _.data } filter { _.getName.startsWith("newrelic-api") }
},
// define the target directory
extractJarsTarget <<= (baseDirectory)(_ / "extracted"),
// task to extract jar files
extractJars <<= (jarsToExtract, extractJarsTarget, streams) map { (jars, target, streams) =>
jars foreach { jar =>
streams.log.info("Extracting " + jar.getName + " to " + target)
IO.unzip(jar, target)
}
},
// make it run before compile
compile in Compile <<= extractJars map { _ => sbt.inc.Analysis.Empty }
)
lazy val test: Project = Project("test", file(".")) settings (testSettings: _*)
}
If you simply have jar files to extract, you can add them as unmanaged dependencies, ie. putting them into the /lib folder. See: https://github.com/harrah/xsbt/wiki/Getting-Started-Library-Dependencies
If you really have zip files (or want to extract the unmanaged dependencies), you can change the above code to list them:
// list jar files to be extracted
jarsToExtract <<= (baseDirectory) map { dir => Seq(dir / "lib" / "newrelic-api-2.2.1.zip") },
You should now be able to manually extract them from sbt and they should automatically be extracted before compile:
> clean
[success] Total time: 0 s, completed Oct 12, 2012 5:39:16 PM
> extract-jars
[info] Extracting newrelic-api-2.2.1.zip to /Users/balagez/Sites/test/extracted
[success] Total time: 0 s, completed Oct 12, 2012 5:39:22 PM
> compile
[info] Extracting newrelic-api-2.2.1.zip to /Users/balagez/Sites/test/extracted
[success] Total time: 0 s, completed Oct 12, 2012 5:39:24 PM
Now you can add a new task or extend the existing one which extracts the zip file from the extracted dependency. If you don't need the contents of the dependency, you can use the task-temporary-directory setting which gives you a temporary directory writable by sbt:
// define the target directory
extractJarsTarget <<= taskTemporaryDirectory,