Question

I would need to have two different projects, let’s say internal and external, which use the same data layer, and I would like to avoid replicating the configuration file for dryness reasons.

I have looked to the sub projects documentation at http://www.playframework.org/documentation/2.0.2/SBTSubProjects but the doc is pretty short.

I am now aware of the possibility to modularize the configuration, thanks to @Georg Engel

import sbt._
import Keys._
import PlayProject._

object ApplicationBuild extends Build {

    val appName         = "MyApp"
    val appVersion      = "1.0-SNAPSHOT"

    val appDependencies = Seq(
      // Add your project dependencies here,
    )

    lazy val common = Project(appName + "-common", file("modules/common"))

    lazy val website = PlayProject(
    appName + "-website", appVersion, path = file("modules/website")
    ).dependsOn(common)

    lazy val adminArea = PlayProject(
    appName + "-admin", appVersion, path = file("modules/admin")
    ).dependsOn(common)

    lazy val main = PlayProject(appName, appVersion, appDependencies, mainLang = SCALA).settings(
      // Add your own project settings here      
    ).dependsOn(
    website, adminArea
    )


}

and the compilation errors I had where only due to the reverse router (canceling routes but not controller actions result in this)

Answer 1

We are using submodules like this (where “core” is the shared submodule):

Build.scala

val coreModule = PlayProject(appName + "-core", "1.0", appDependencies, path = file("modules") / "core")

val main = PlayProject(appName + "-app", appVersion, appDependencies, mainLang = SCALA).settings(
  // Add your own project settings here      
).dependsOn(coreModule).aggregate(coreModule)

Unfortunatelly submodules have to live under the project tree (“../core” as path isn’t possible) – so we are using git submodules to get the shared module into the tree:

git submodule add git://git.example.com/modules.git modules

git submodule init

git submodule update

Propably SVN externals, mercurial submodules etc. will do this job too.