First pass at DokkaPlugin.

src/main/kotlin/com/beust/kobalt/plugin/dokka/DokkaPlugin.kt

@@ -0,0 +1,93 @@
+package com.beust.kobalt.plugin.dokka
+
+import com.beust.kobalt.JavaInfo
+import com.beust.kobalt.SystemProperties
+import com.beust.kobalt.TaskResult
+import com.beust.kobalt.api.BasePlugin
+import com.beust.kobalt.api.Kobalt
+import com.beust.kobalt.api.Project
+import com.beust.kobalt.api.annotation.Directive
+import com.beust.kobalt.api.annotation.Task
+import com.beust.kobalt.internal.JvmCompilerPlugin
+import com.beust.kobalt.maven.DepFactory
+import com.beust.kobalt.misc.RunCommand
+import com.beust.kobalt.misc.log
+import java.io.File
+import javax.inject.Inject
+import javax.inject.Singleton
+
+@Singleton
+class DokkaPlugin @Inject constructor(val depFactory: DepFactory) : BasePlugin() {
+    override val name = PLUGIN_NAME
+
+    companion object {
+        const val PLUGIN_NAME = "dokka"
+        const val DOKKA_ID = "org.jetbrains.dokka:dokka-fatjar:0.9.1"
+    }
+
+    /**
+     * Probably no point in running this task if "assemble" hasn't completed.
+     */
+    @Task(name = "dokka", description = "Run dokka",
+            runBefore = arrayOf("compile")
+//            runAfter = arrayOf(PackagingPlugin.TASK_ASSEMBLE)
+    )
+    fun taskDokka(project: Project) : TaskResult {
+        val javaExecutable = JavaInfo.create(File(SystemProperties.javaBase)).javaExecutable!!
+        val config = configurations[project.name]
+        val classpath = context.dependencyManager.calculateDependencies(project, context)
+        val buildDir = project.projectProperties.getString(JvmCompilerPlugin.BUILD_DIR)
+        val classpathString = (classpath.map { it.jarFile.get().absolutePath } +
+                listOf(buildDir))
+            .joinToString(File.pathSeparator)
+        val dokkaJar = depFactory.create(DOKKA_ID, context.executors.miscExecutor).jarFile.get().absolutePath
+        if (config != null) {
+            val args = listOf(
+                    "-classpath", classpathString,
+                    "-jar", dokkaJar,
+                    "src/main/kotlin") +
+                config.args
+            RunCommand(javaExecutable.absolutePath).run(args, successCallback = {
+                println("COMMAND SUCCESS")
+            })
+        } else {
+            log(2, "No dokka configuration found for project ${project.name}, skipping it")
+        }
+        return TaskResult()
+    }
+
+    private val configurations = hashMapOf<String, DokkaConfig>()
+
+    fun addDokkaConfiguration(name: String, dokkaConfig: DokkaConfig) {
+        configurations.put(name, dokkaConfig)
+    }
+}
+
+/*
+output - the output directory where the documentation is generated
+format - the output format:
+html - HTML (default)
+markdown - Markdown
+jekyll - Markdown adapted for Jekyll sites
+javadoc - Javadoc (showing how the project can be accessed from Java)
+classpath - list of directories or .jar files to include in the classpath (used for resolving references)
+samples - list of directories containing sample code (documentation for those directories is not generated but declarations from them can be referenced using the @sample tag)
+module - the name of the module being documented (used as the root directory of the generated documentation)
+include - names of files containing the documentation for the module and individual packages
+nodeprecated
+ */
+class DokkaConfig(project: Project) {
+    val args = arrayListOf<String>()
+    fun args(vararg options: String) {
+        args.addAll(options)
+    }
+}
+
+@Directive
+public fun Project.dokka(init: DokkaConfig.() -> Unit) {
+    with(DokkaConfig(this)) {
+        init()
+        (Kobalt.findPlugin(DokkaPlugin.PLUGIN_NAME) as DokkaPlugin).addDokkaConfiguration(name, this)
+    }
+}
+