Extracted accessor into interface and added to script engine context to allow access to script extensions from script engine factories (#1843)

Signed-off-by: Jonathan Gilbert <jpg@trillica.com>

bundles/org.openhab.core.automation.module.script/src/main/java/org/openhab/core/automation/module/script/ScriptEngineFactory.java

@@ -40,6 +40,11 @@ public interface ScriptEngineFactory {
      */
     String CONTEXT_KEY_ENGINE_IDENTIFIER = "oh.engine-identifier";
 
+    /**
+     * Key to access Extension Accessor {@link ScriptExtensionAccessor}
+     */
+    String CONTEXT_KEY_EXTENSION_ACCESSOR = "oh.extension-accessor";
+
     /**
      * This method returns a list of file extensions and MimeTypes that are supported by the ScriptEngine, e.g. py,
      * application/python, js, application/javascript, etc.

bundles/org.openhab.core.automation.module.script/src/main/java/org/openhab/core/automation/module/script/ScriptExtensionAccessor.java

@@ -0,0 +1,43 @@
+/**
+ * Copyright (c) 2010-2020 Contributors to the openHAB project
+ *
+ * See the NOTICE file(s) distributed with this work for additional
+ * information.
+ *
+ * This program and the accompanying materials are made available under the
+ * terms of the Eclipse Public License 2.0 which is available at
+ * http://www.eclipse.org/legal/epl-2.0
+ *
+ * SPDX-License-Identifier: EPL-2.0
+ */
+package org.openhab.core.automation.module.script;
+
+import java.util.Map;
+
+import org.eclipse.jdt.annotation.NonNullByDefault;
+
+/**
+ * Accessor allowing script engines to lookup presets.
+ *
+ * @author Jonathan Gilbert - Initial contribution
+ */
+@NonNullByDefault
+public interface ScriptExtensionAccessor {
+
+    /**
+     * Access the default presets for a script engine
+     *
+     * @param scriptIdentifier the identifier for the script engine
+     * @return map of preset objects
+     */
+    Map<String, Object> findDefaultPresets(String scriptIdentifier);
+
+    /**
+     * Access specific presets for a script engine
+     *
+     * @param preset the name of the preset
+     * @param scriptIdentifier the identifier for the script engine
+     * @return map of preset objects
+     */
+    Map<String, Object> findPreset(String preset, String scriptIdentifier);
+}

bundles/org.openhab.core.automation.module.script/src/main/java/org/openhab/core/automation/module/script/internal/ScriptEngineManagerImpl.java

@@ -13,6 +13,7 @@
 package org.openhab.core.automation.module.script.internal;
 
 import static org.openhab.core.automation.module.script.ScriptEngineFactory.CONTEXT_KEY_ENGINE_IDENTIFIER;
+import static org.openhab.core.automation.module.script.ScriptEngineFactory.CONTEXT_KEY_EXTENSION_ACCESSOR;
 
 import java.io.InputStreamReader;
 import java.util.HashMap;
@@ -144,6 +145,8 @@ public class ScriptEngineManagerImpl implements ScriptEngineManager {
 
                     scriptContext.setAttribute(CONTEXT_KEY_ENGINE_IDENTIFIER, engineIdentifier,
                             ScriptContext.ENGINE_SCOPE);
+                    scriptContext.setAttribute(CONTEXT_KEY_EXTENSION_ACCESSOR, scriptExtensionManager,
+                            ScriptContext.ENGINE_SCOPE);
                 } else {
                     logger.error("ScriptEngine for language '{}' could not be created for identifier: {}", scriptType,
                             engineIdentifier);

bundles/org.openhab.core.automation.module.script/src/main/java/org/openhab/core/automation/module/script/internal/ScriptExtensionManager.java

@@ -24,6 +24,7 @@ import javax.script.ScriptEngine;
 import org.eclipse.jdt.annotation.NonNullByDefault;
 import org.eclipse.jdt.annotation.Nullable;
 import org.openhab.core.automation.module.script.ScriptEngineFactory;
+import org.openhab.core.automation.module.script.ScriptExtensionAccessor;
 import org.openhab.core.automation.module.script.ScriptExtensionProvider;
 import org.osgi.service.component.annotations.Component;
 import org.osgi.service.component.annotations.Reference;
@@ -37,7 +38,7 @@ import org.osgi.service.component.annotations.ReferencePolicy;
  */
 @Component(service = ScriptExtensionManager.class)
 @NonNullByDefault
-public class ScriptExtensionManager {
+public class ScriptExtensionManager implements ScriptExtensionAccessor {
 
     private final Set<ScriptExtensionProvider> scriptExtensionProviders = new CopyOnWriteArraySet<>();
 
@@ -100,19 +101,36 @@ public class ScriptExtensionManager {
 
     public void importDefaultPresets(ScriptEngineFactory engineProvider, ScriptEngine scriptEngine,
             String scriptIdentifier) {
-        for (String preset : getDefaultPresets()) {
+
-            importPreset(preset, engineProvider, scriptEngine, scriptIdentifier);
+        engineProvider.scopeValues(scriptEngine, findDefaultPresets(scriptIdentifier));
-        }
     }
 
     public Map<String, Object> importPreset(String preset, ScriptEngineFactory engineProvider,
             ScriptEngine scriptEngine, String scriptIdentifier) {
+
+        Map<String, Object> rv = findPreset(preset, scriptIdentifier);
+
+        engineProvider.scopeValues(scriptEngine, rv);
+
+        return rv;
+    }
+
+    public Map<String, Object> findDefaultPresets(String scriptIdentifier) {
+        Map<String, Object> allValues = new HashMap<>();
+
+        for (String preset : getDefaultPresets()) {
+            allValues.putAll(findPreset(preset, scriptIdentifier));
+        }
+
+        return allValues;
+    }
+
+    public Map<String, Object> findPreset(String preset, String scriptIdentifier) {
         Map<String, Object> allValues = new HashMap<>();
         for (ScriptExtensionProvider provider : scriptExtensionProviders) {
             if (provider.getPresets().contains(preset)) {
                 Map<String, Object> scopeValues = provider.importPreset(scriptIdentifier, preset);
 
-                engineProvider.scopeValues(scriptEngine, scopeValues);
                 allValues.putAll(scopeValues);
             }
         }