Dynamically extracting SASS

Build.scala

  val main = play.Project(appName, appVersion, appDependencies).settings(
  
    resourceGenerators in Compile <+= (target, resourceManaged in Compile, cacheDirectory, streams) map { (target, resources, cache, streams) =>

      val logger = streams.log
      val sassWorkingDir = target / "sass-blabla"

      if(!sassWorkingDir.exists) {

        val maybeSass = this.getClass.getClassLoader.getParent.asInstanceOf[java.net.URLClassLoader].getURLs.map(_.getFile).map(file).find { file =>
          logger.info(file.getAbsolutePath)
          // check if it is the file we are looking for
          false
        }

        maybeSass.map { zipFile =>
          IO.unzip(zipFile, sassWorkingDir)
        }.orElse {
          sys.error("OOPS. missing SASS?")
        }

      }
       
      // Here `sassWorkingDir` references a directory containing the whole SASS Stuff, so you can work with it and process resources as usual.

      // ...

      // The dynamically generated ressources (CSS) here as expected
      Seq.empty[File]
    }

  )