Created ExtensibleExtension interface (#600)

* copied and pasted from plugin file, replaced with extension keywords Signed-off-by: Bexultan_Tokan <[email protected]> * used gradlew spotless Signed-off-by: Bexultan_Tokan <[email protected]> * deleted unnecessary comments Signed-off-by: Bexultan_Tokan <[email protected]> * returned comments, removed @opensearch.api Signed-off-by: Bexultan_Tokan <[email protected]> --------- Signed-off-by: Bexultan_Tokan <[email protected]>
opensearch-project · Apr 3, 2023 · c650fa2 · c650fa2
1 parent e384dae
commit c650fa2
Showing 1 changed file with 46 additions and 0 deletions.
diff --git a/src/main/java/org/opensearch/sdk/ExtensibleExtension.java b/src/main/java/org/opensearch/sdk/ExtensibleExtension.java
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+/*
+ * Copyright OpenSearch Contributors
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+package org.opensearch.sdk;
+
+import java.util.List;
+
+/**
+ * An extension point for {@link Extension} implementations to be themselves extensible.
+ *
+ * This class provides a callback for extensible Extensions to be informed of other Extensions
+ * which extend them.
+ *
+ */
+
+public interface ExtensibleExtension {
+    /**
+     * Extension point for external Extensions to be extendable
+     */
+
+    interface ExtensionLoader {
+        /**
+         * Load extensions of the type from all extending Extensions. The concrete extensions must have either a no-arg constructor
+         * or a single-arg constructor accepting the specific Extension class.
+         * @param extensionPointType the extension point type
+         * @param <T> extension point type
+         * @return all implementing extensions.
+         */
+        <T> List<T> loadExtensions(Class<T> extensionPointType);
+    }
+
+    /**
+     * Allow this Extension to load extensions from other Extensions.
+     *
+     * This method is called once only, after initializing this Extension and all Extensions extending this Extension. It is called before
+     * any other methods on this Extension instance are called.
+     * @param loader the loader to use to load extensions
+     */
+    default void loadExtensions(ExtensionLoader loader) {}
+}