IProjectContributor.

src/main/kotlin/com/beust/kobalt/api/BasePlugin.kt

@@ -1,12 +1,8 @@
 package com.beust.kobalt.api
 
-import com.beust.kobalt.BasePluginTask
 import com.beust.kobalt.Plugins
 import com.beust.kobalt.internal.TaskManager
-import com.beust.kobalt.internal.TaskResult
+import java.util.*
-import com.beust.kobalt.internal.TaskResult2
-import java.util.ArrayList
-import java.util.concurrent.Callable
 import kotlin.properties.Delegates
 
 abstract public class BasePlugin : Plugin {
@@ -15,4 +11,11 @@ abstract public class BasePlugin : Plugin {
     override var methodTasks = arrayListOf<Plugin.MethodTask>()
     override fun accept(project: Project) = true
     var plugins : Plugins by Delegates.notNull()
+
+    protected val projects = arrayListOf<ProjectDescription>()
+
+    fun addProject(project: Project, dependsOn: Array<out Project>) {
+        projects.add(ProjectDescription(project, dependsOn.toList()))
+    }
+
 }

src/main/kotlin/com/beust/kobalt/api/Kobalt.kt

@@ -1,7 +1,6 @@
 package com.beust.kobalt.api
 
 import com.beust.kobalt.Plugins
-import com.beust.kobalt.misc.Topological
 import com.google.inject.Injector
 import java.io.File
 import java.io.InputStream
@@ -83,21 +82,6 @@ public class Kobalt {
 
         val version = properties.getProperty(PROPERTY_KOBALT_VERSION)
 
-        val topologicalProjects = Topological<Project>()
-
-        /**
-         * Used by projects to specify that they depend on other projects, e.g.
-         * val p = javaProject(project1, project2) { ... }
-         */
-        fun declareProjectDependencies(project: Project, projects: Array<out Project>) {
-            topologicalProjects.addEdge(project, projects)
-        }
-
-        /**
-         * @return the projects sorted topologically.
-         */
-        fun sortProjects(allProjects: ArrayList<Project>) = topologicalProjects.sort(allProjects)
-
         fun findPlugin(name: String) = Plugins.findPlugin(name)
     }
 }

src/main/kotlin/com/beust/kobalt/api/KobaltPluginFile.kt

@@ -0,0 +1,16 @@
+package com.beust.kobalt.api
+
+import com.beust.kobalt.plugin.java.JavaPlugin
+import com.beust.kobalt.plugin.kotlin.KotlinPlugin
+
+class ProjectDescription(val project: Project, val dependsOn: List<Project>)
+
+interface IProjectContributor {
+    fun projects() : List<ProjectDescription>
+}
+
+class KobaltPluginFile {
+    fun <T> instanceOf(c: Class<T>) = Kobalt.INJECTOR.getInstance(c)
+    val projectContributors : List<Class<out IProjectContributor>> =
+            arrayListOf(JavaPlugin::class.java, KotlinPlugin::class.java)
+}

src/main/kotlin/com/beust/kobalt/api/Plugin.kt

@@ -6,7 +6,7 @@ import com.beust.kobalt.internal.TaskManager
 import com.beust.kobalt.internal.TaskResult
 import com.beust.kobalt.internal.TaskResult2
 import java.lang.reflect.Method
-import java.util.ArrayList
+import java.util.*
 
 public interface Plugin {
     val name: String

src/main/kotlin/com/beust/kobalt/kotlin/BuildFileCompiler.kt

@@ -2,13 +2,11 @@ package com.beust.kobalt.kotlin
 
 import com.beust.kobalt.Args
 import com.beust.kobalt.Plugins
-import com.beust.kobalt.api.Kobalt
+import com.beust.kobalt.api.*
-import com.beust.kobalt.api.KobaltContext
-import com.beust.kobalt.api.Plugin
-import com.beust.kobalt.api.Project
 import com.beust.kobalt.api.annotation.Task
 import com.beust.kobalt.maven.KobaltException
 import com.beust.kobalt.misc.KFiles
+import com.beust.kobalt.misc.Topological
 import com.beust.kobalt.misc.countChar
 import com.beust.kobalt.misc.log
 import com.beust.kobalt.plugin.kotlin.kotlinCompilePrivate
@@ -22,11 +20,12 @@ import java.net.URL
 import java.net.URLClassLoader
 import java.nio.charset.Charset
 import java.nio.file.Paths
+import java.util.*
 import java.util.jar.JarInputStream
 import javax.inject.Inject
 
 public class BuildFileCompiler @Inject constructor(@Assisted("buildFiles") val buildFiles: List<BuildFile>,
-        val files: KFiles, val plugins: Plugins) {
+        val files: KFiles, val plugins: Plugins, val kobaltPluginFile: KobaltPluginFile) {
 
     interface IFactory {
         fun create(@Assisted("buildFiles") buildFiles: List<BuildFile>) : BuildFileCompiler
@@ -220,9 +219,27 @@ public class BuildFileCompiler @Inject constructor(@Assisted("buildFiles") val b
             stream?.close()
         }
 
-        // Now that we all the projects, sort them topologically
+        //
-        val result = BuildScriptInfo(Kobalt.sortProjects(projects), classLoader)
+        // Now that the build file has run, fetch all the project contributors, grab the projects from them and sort
+        // them topologically
+        //
+        Topological<Project>().let { topologicalProjects ->
+            val all = hashSetOf<Project>()
+            kobaltPluginFile.projectContributors.forEach { cls ->
+                val ip: IProjectContributor = kobaltPluginFile.instanceOf(cls)
+                val descriptions = ip.projects()
+                descriptions.forEach { pd ->
+                    all.add(pd.project)
+                    pd.dependsOn.forEach { dependsOn ->
+                        topologicalProjects.addEdge(pd.project, dependsOn)
+                        all.add(dependsOn)
+                    }
+                }
+            }
+            val result = BuildScriptInfo(topologicalProjects.sort(ArrayList(all)), classLoader)
+
             observable.onNext(result)
             return result
         }
+    }
 }

src/main/kotlin/com/beust/kobalt/plugin/java/JavaPlugin.kt

@@ -1,5 +1,7 @@
 package com.beust.kobalt.plugin.java
 
+import com.beust.kobalt.api.BasePlugin
+import com.beust.kobalt.api.IProjectContributor
 import com.beust.kobalt.api.Kobalt
 import com.beust.kobalt.api.Project
 import com.beust.kobalt.api.annotation.Directive
@@ -27,7 +29,8 @@ public class JavaPlugin @Inject constructor(
         override val executors: KobaltExecutors,
         val javaCompiler: JavaCompiler,
         override val jvmCompiler: JvmCompiler)
-        : JvmCompilerPlugin(localRepo, files, depFactory, dependencyManager, executors, jvmCompiler) {
+        : JvmCompilerPlugin(localRepo, files, depFactory, dependencyManager, executors, jvmCompiler),
+            IProjectContributor {
 
     init {
         Kobalt.registerCompiler(JavaCompilerInfo())
@@ -104,13 +107,14 @@ public class JavaPlugin @Inject constructor(
         compilerArgs.addAll(args)
     }
 
+    override fun projects() = projects
 }
 
 @Directive
 public fun javaProject(vararg project: Project, init: JavaProject.() -> Unit): JavaProject {
     return JavaProject().apply {
         init()
-        Kobalt.declareProjectDependencies(this, project)
+        (Kobalt.findPlugin("kotlin") as BasePlugin).addProject(this, project)
     }
 }
 

src/main/kotlin/com/beust/kobalt/plugin/kotlin/KotlinPlugin.kt

@@ -1,5 +1,7 @@
 package com.beust.kobalt.plugin.kotlin
 
+import com.beust.kobalt.api.BasePlugin
+import com.beust.kobalt.api.IProjectContributor
 import com.beust.kobalt.api.Kobalt
 import com.beust.kobalt.api.Project
 import com.beust.kobalt.api.annotation.Directive
@@ -25,7 +27,8 @@ class KotlinPlugin @Inject constructor(
         override val dependencyManager: DependencyManager,
         override val executors: KobaltExecutors,
         override val jvmCompiler: JvmCompiler)
-        : JvmCompilerPlugin(localRepo, files, depFactory, dependencyManager, executors, jvmCompiler) {
+        : JvmCompilerPlugin(localRepo, files, depFactory, dependencyManager, executors, jvmCompiler),
+            IProjectContributor {
 
     init {
         Kobalt.registerCompiler(KotlinCompilerInfo())
@@ -93,6 +96,8 @@ class KotlinPlugin @Inject constructor(
             output = outputDirectory
         }.compile(project, context)
     }
+
+    override fun projects() = projects
 }
 
 /**
@@ -102,7 +107,7 @@ class KotlinPlugin @Inject constructor(
 fun kotlinProject(vararg project: Project, init: KotlinProject.() -> Unit): KotlinProject {
     return KotlinProject().apply {
         init()
-        Kobalt.declareProjectDependencies(this, project)
+        (Kobalt.findPlugin("kotlin") as BasePlugin).addProject(this, project)
     }
 }