Add plugin interfaces

src/main/scala/plugin/Plugin.scala

@@ -0,0 +1,14 @@
+package plugin
+
+trait Plugin {
+
+  val pluginId: String
+  val pluginName: String
+  val description: String
+  val version: String
+
+  def initialize(registry: PluginRegistry): Unit
+
+  def shutdown(registry: PluginRegistry): Unit
+
+}

src/main/scala/plugin/PluginRegistory.scala

@@ -0,0 +1,87 @@
+package plugin
+
+import java.io.{FilenameFilter, File}
+import java.net.URLClassLoader
+
+import org.slf4j.LoggerFactory
+import util.Directory._
+
+import scala.collection.mutable.ListBuffer
+
+class PluginRegistry {
+
+  private val plugins = new ListBuffer[PluginInfo]
+  private val javaScripts = new ListBuffer[(String, String)]
+
+  def addPlugin(pluginInfo: PluginInfo): Unit = {
+    plugins += pluginInfo
+  }
+
+  def getPlugins(): List[PluginInfo] = plugins.toList
+
+  def addJavaScript(path: String, script: String): Unit = {
+    javaScripts += Tuple2(path, script)
+  }
+
+  def getJavaScripts(): List[(String, String)] = javaScripts.toList
+
+  def getJavaScript(currentPath: String): Option[String] = {
+    println(currentPath)
+    getJavaScripts().find(x => currentPath.matches(x._1)).map(_._2)
+  }
+
+}
+
+object PluginRegistry {
+
+  private val logger = LoggerFactory.getLogger(classOf[PluginRegistry])
+
+  private val instance = new PluginRegistry()
+
+  def apply(): PluginRegistry = instance
+
+  def initialize(): Unit = {
+    new File(PluginHome).listFiles(new FilenameFilter {
+      override def accept(dir: File, name: String): Boolean = name.endsWith(".jar")
+    }).foreach { pluginJar =>
+      val classLoader = new URLClassLoader(Array(pluginJar.toURI.toURL), Thread.currentThread.getContextClassLoader)
+      try {
+        val plugin = classLoader.loadClass("Plugin").newInstance().asInstanceOf[Plugin]
+        plugin.initialize(instance)
+        instance.addPlugin(PluginInfo(
+          pluginId    = plugin.pluginId,
+          pluginName  = plugin.pluginName,
+          version     = plugin.version,
+          description = plugin.description,
+          pluginClass = plugin
+        ))
+      } catch {
+        case e: Exception => {
+          logger.error(s"Error during plugin initialization", e)
+        }
+      }
+    }
+  }
+
+  def shutdown(): Unit = {
+    instance.getPlugins().foreach { pluginInfo =>
+      try {
+        pluginInfo.pluginClass.shutdown(instance)
+      } catch {
+        case e: Exception => {
+          logger.error(s"Error during plugin shutdown", e)
+        }
+      }
+    }
+  }
+
+
+}
+
+case class PluginInfo(
+  pluginId: String,
+  pluginName: String,
+  version: String,
+  description: String,
+  pluginClass: Plugin
+)

src/main/scala/servlet/AutoUpdateListener.scala

@@ -11,6 +11,7 @@ import util.ControlUtil._
 import util.JDBCUtil._
 import org.eclipse.jgit.api.Git
 import util.Directory
+import plugin._
 
 object AutoUpdate {
   
@@ -211,6 +212,7 @@ class AutoUpdateListener extends ServletContextListener {
     val context = event.getServletContext
     context.setInitParameter("db.url", s"jdbc:h2:${DatabaseHome};MVCC=true")
 
+    // Migration
     defining(getConnection(event.getServletContext)){ conn =>
       logger.debug("Start schema update")
       try {
@@ -234,9 +236,14 @@ class AutoUpdateListener extends ServletContextListener {
       }
       logger.debug("End schema update")
     }
+
+    // Load plugins
+    PluginRegistry.initialize()
   }
 
   def contextDestroyed(sce: ServletContextEvent): Unit = {
+    // Shutdown plugins
+    PluginRegistry.shutdown()
   }
 
   private def getConnection(servletContext: ServletContext): Connection =

src/main/twirl/main.scala.html

@@ -82,5 +82,10 @@
         });
       });
     </script>
+    @plugin.PluginRegistry().getJavaScript(request.getRequestURI).map { script =>
+      <script>
+        @Html(script)
+      </script>
+    }
   </body>
 </html>