Updated plugin management

dataforge-context/src/commonMain/kotlin/hep/dataforge/context/Plugin.kt

@@ -46,7 +46,7 @@ interface Plugin : Named, ContextAware, Provider, MetaRepr, Configurable {
      *
      * @return
      */
-    fun dependsOn(): List<PluginTag> = emptyList()
+    fun dependsOn(): List<PluginFactory<*>> = emptyList()
 
     /**
      * Start this plugin and attach registration info to the context. This method

dataforge-context/src/commonMain/kotlin/hep/dataforge/context/PluginManager.kt

@@ -118,6 +118,15 @@ class PluginManager(override val context: Context) : ContextAware, Iterable<Plug
         }
     }
 
+    fun load(factory: PluginFactory<*>, meta: Meta = EmptyMeta): Plugin{
+        val loaded = get(factory.tag, false)
+        return when {
+            loaded == null -> factory.build(meta)
+            loaded.config == meta -> loaded // if meta is the same, return existing plugin
+            else -> throw RuntimeException("Can't load plugin with tag ${factory.tag}. Plugin with this tag and different configuration already exists in context.")
+        }
+    }
+
     /**
      * Load plugin by its class and meta. Ignore if plugin with this meta is already loaded.
      * Throw an exception if there exists plugin with the same type, but different meta

dataforge-context/src/commonMain/kotlin/hep/dataforge/context/PluginRepository.kt

@@ -4,23 +4,23 @@ import hep.dataforge.meta.Meta
 import hep.dataforge.meta.configure
 import kotlin.reflect.KClass
 
-interface PluginFactory {
+interface PluginFactory<T: Plugin> {
     val tag: PluginTag
-    val type: KClass<out Plugin>
-    fun build(): Plugin
+    val type: KClass<out T>
+    fun build(): T
 }
 
-fun PluginFactory.build(meta: Meta) = build().configure(meta)
+fun PluginFactory<*>.build(meta: Meta) = build().configure(meta)
 
 
 expect object PluginRepository {
 
-    fun register(factory: PluginFactory)
+    fun register(factory: PluginFactory<*>)
 
     /**
      * List plugins available in the repository
      */
-    fun list(): Sequence<PluginFactory>
+    fun list(): Sequence<PluginFactory<*>>
 
 }
 
@@ -31,15 +31,16 @@ fun PluginRepository.fetch(tag: PluginTag): Plugin =
     PluginRepository.list().find { it.tag.matches(tag) }?.build()
         ?: error("Plugin with tag $tag not found in the repository")
 
-fun PluginRepository.register(tag: PluginTag, type: KClass<out Plugin>, constructor: () -> Plugin) {
-    val factory = object : PluginFactory {
+fun <T: Plugin> PluginRepository.register(tag: PluginTag, type: KClass<out T>, constructor: () -> T): PluginFactory<T> {
+    val factory = object : PluginFactory<T> {
         override val tag: PluginTag = tag
-        override val type: KClass<out Plugin> = type
+        override val type: KClass<out T> = type
 
-        override fun build(): Plugin = constructor()
+        override fun build(): T = constructor()
 
     }
     PluginRepository.register(factory)
+    return factory
 }
 
 inline fun <reified T : Plugin> PluginRepository.register(tag: PluginTag, noinline constructor: () -> T) =

dataforge-context/src/jsMain/kotlin/hep/dataforge/context/PluginRepository.kt

@@ -3,14 +3,14 @@ package hep.dataforge.context
 
 actual object PluginRepository {
 
-    private val factories: MutableSet<PluginFactory> = HashSet()
+    private val factories: MutableSet<PluginFactory<*>> = HashSet()
 
-    actual fun register(factory: PluginFactory) {
+    actual fun register(factory: PluginFactory<*>) {
         factories.add(factory)
     }
 
     /**
      * List plugins available in the repository
      */
-    actual fun list(): Sequence<PluginFactory> = factories.asSequence()
+    actual fun list(): Sequence<PluginFactory<*>> = factories.asSequence()
 }

dataforge-context/src/jvmMain/kotlin/hep/dataforge/context/PluginRepository.kt

@@ -2,16 +2,16 @@ package hep.dataforge.context
 
 actual object PluginRepository {
 
-    private val factories: MutableSet<PluginFactory> = HashSet()
+    private val factories: MutableSet<PluginFactory<*>> = HashSet()
 
-    actual fun register(factory: PluginFactory) {
+    actual fun register(factory: PluginFactory<*>) {
         factories.add(factory)
     }
 
     /**
      * List plugins available in the repository
      */
-    actual fun list(): Sequence<PluginFactory> =
+    actual fun list(): Sequence<PluginFactory<*>> =
         factories.asSequence() + Global.services()
 
 }

dataforge-output/src/commonMain/kotlin/hep/dataforge/output/OutputManager.kt

@@ -1,9 +1,6 @@
 package hep.dataforge.output
 
-import hep.dataforge.context.AbstractPlugin
-import hep.dataforge.context.Context
-import hep.dataforge.context.Plugin
-import hep.dataforge.context.PluginTag
+import hep.dataforge.context.*
 import hep.dataforge.context.PluginTag.Companion.DATAFORGE_GROUP
 import hep.dataforge.meta.EmptyMeta
 import hep.dataforge.meta.Meta
@@ -24,13 +21,18 @@ interface OutputManager : Plugin {
      * @param name represents the name inside the node.
      * @param meta configuration for [Output] (not for rendered object)
      */
-    operator fun <T : Any> get(type: KClass<out T>, name: Name, stage: Name = EmptyName, meta: Meta = EmptyMeta): Output<T>
+    operator fun <T : Any> get(
+        type: KClass<out T>,
+        name: Name,
+        stage: Name = EmptyName,
+        meta: Meta = EmptyMeta
+    ): Output<T>
 }
 
 /**
  * Get an output manager for a context
  */
-val Context.output: OutputManager get() = plugins.get() ?: ConsoleOutputManager
+val Context.output: OutputManager get() = plugins.get() ?: ConsoleOutputManager()
 
 /**
  * Get an output with given [name], [stage] and reified content type
@@ -47,7 +49,7 @@ inline operator fun <reified T : Any> OutputManager.get(
  * Directly render an object using the most suitable renderer
  */
 fun OutputManager.render(obj: Any, name: Name, stage: Name = EmptyName, meta: Meta = EmptyMeta) =
-        get(obj::class, name,stage).render(obj,meta)
+    get(obj::class, name, stage).render(obj, meta)
 
 /**
  * System console output.
@@ -55,10 +57,18 @@ fun OutputManager.render(obj: Any, name: Name, stage: Name = EmptyName, meta: Me
  */
 expect val ConsoleOutput: Output<Any>
 
-object ConsoleOutputManager : AbstractPlugin(), OutputManager {
-    override val tag: PluginTag = PluginTag("output.console", group = DATAFORGE_GROUP)
+class ConsoleOutputManager : AbstractPlugin(), OutputManager {
+    override val tag: PluginTag get() = ConsoleOutputManager.tag
 
     override fun <T : Any> get(type: KClass<out T>, name: Name, stage: Name, meta: Meta): Output<T> = ConsoleOutput
+
+    companion object : PluginFactory<ConsoleOutputManager> {
+        override val tag = PluginTag("output.console", group = DATAFORGE_GROUP)
+
+        override val type = ConsoleOutputManager::class
+
+        override fun build() = ConsoleOutputManager()
+    }
 }
 
 /**