merged startup extension into KLighD's main extension.

Moved the initialization and loading of all extensions into the static part after creating the instance, so that the startupHook extension may use the instance and modify it directly.
kieler · NiklasRentzCAU · Sep 18, 2020 · Jun 12, 2019 · Jun 12, 2019 · Jun 12, 2019
commit 588a14931ad15079c947b726748d92d155e374bf
diff --git a/plugins/de.cau.cs.kieler.klighd/schema/extensions.exsd b/plugins/de.cau.cs.kieler.klighd/schema/extensions.exsd
@@ -28,6 +28,7 @@
             <element ref="offscreenRenderer"/>
             <element ref="handler"/>
             <element ref="preservedProperties"/>
+            <element ref="startupHook"/>
          </choice>
          <attribute name="point" type="string" use="required">
             <annotation>
@@ -319,6 +320,21 @@ Note: Implementations should not directly implement the required interface but s
       </complexType>
    </element>
 
+   <element name="startupHook">
+      <complexType>
+         <attribute name="class" type="string" use="required">
+            <annotation>
+               <documentation>
+                  Class that is to be used to programmatically register KLighD extensions during startup.
+               </documentation>
+               <appinfo>
+                  <meta.attribute kind="java" basedOn=":de.cau.cs.kieler.klighd.IKlighdStartupHook"/>
+               </appinfo>
+            </annotation>
+         </attribute>
+      </complexType>
+   </element>
+
    <annotation>
       <appinfo>
          <meta.section type="since"/>

diff --git a/plugins/de.cau.cs.kieler.klighd/schema/klighdStartupHook.exsd b/plugins/de.cau.cs.kieler.klighd/schema/klighdStartupHook.exsd
diff --git a/plugins/de.cau.cs.kieler.klighd/src/de/cau/cs/kieler/klighd/KlighdDataManager.java b/plugins/de.cau.cs.kieler.klighd/src/de/cau/cs/kieler/klighd/KlighdDataManager.java
@@ -69,9 +69,6 @@ public final class KlighdDataManager {
     /** identifier of the extension point for model transformations. */
     private static final String EXTP_ID_DIAGRAM_SYNTHESES = "de.cau.cs.kieler.klighd.diagramSyntheses";
 
-    /** identifier of the extension point for startup hooks. */
-    private static final String EXTP_ID_STARTUP_HOOK = "de.cau.cs.kieler.klighd.klighdStartupHook";
-
     /** name of the 'viewer' element. */
     private static final String ELEMENT_VIEWER = "viewer";
 
@@ -161,11 +158,25 @@ public final class KlighdDataManager {
      */
     static {
         instance = new KlighdDataManager();
-        // Load the startup hooks after creating the instance, as they should use this instance to hook into.
+
         if (Klighd.IS_PLATFORM_RUNNING) {
-            loadStartupHooksViaExtensionPoint();
+            // load the data from the extension points
+            instance.loadKlighdExtensionsViaExtensionPoint();
+            try {
+                instance.loadDiagramSynthesesViaExtensionPoint(instance.idSynthesisMapping, instance.typeSynthesisMapping);
+
+            } catch (final Exception e) {
+                instance.idSynthesisMapping.clear();
+                instance.typeSynthesisMapping.clear();
+
+                Klighd.handle(
+                        new Status(IStatus.ERROR, Klighd.PLUGIN_ID,
+                                "KLighD: Unexptected failure while loading registered diagram syntheses.", e));
+            }
+
         } else {
-            loadStartupHooksViaServiceLoader();
+            instance.loadDiagramSynthesesViaServiceLoader(instance.idSynthesisMapping, instance.typeSynthesisMapping);
+            instance.loadKlighdExtensionsViaServiceLoader();
         }
     }
 
@@ -179,10 +190,10 @@ public static KlighdDataManager getInstance() {
     }
 
     /** the mapping of ids to the corresponding instances of {@link ISynthesis}. */
-    private final Map<String, ISynthesis> idSynthesisMapping;
+    private final Map<String, ISynthesis> idSynthesisMapping = Maps.newLinkedHashMap();
 
     /** the mapping of types to the corresponding instances of {@link ISynthesis}. */
-    private final Multimap<Class<?>, ISynthesis> typeSynthesisMapping;
+    private final Multimap<Class<?>, ISynthesis> typeSynthesisMapping = ArrayListMultimap.create();
 
     /**
      * A caching map that avoids the effort of determining the correct syntheses for a given type
@@ -227,33 +238,7 @@ public static KlighdDataManager getInstance() {
     /**
      * A private constructor to prevent instantiation.
      */
-    private KlighdDataManager() {
-        final Map<String, ISynthesis> id2Synthesis = Maps.newLinkedHashMap();
-        final Multimap<Class<?>, ISynthesis> type2Syntheses = ArrayListMultimap.create();
-
-        if (Klighd.IS_PLATFORM_RUNNING) {
-            // load the data from the extension points
-            loadKlighdExtensionsViaExtensionPoint();
-            try {
-                loadDiagramSynthesesViaExtensionPoint(id2Synthesis, type2Syntheses);
-
-            } catch (final Exception e) {
-                id2Synthesis.clear();
-                type2Syntheses.clear();
-
-                Klighd.handle(
-                        new Status(IStatus.ERROR, Klighd.PLUGIN_ID,
-                                "KLighD: Unexptected failure while loading registered diagram syntheses.", e));
-            }
-
-        } else {
-            loadDiagramSynthesesViaServiceLoader(id2Synthesis, type2Syntheses);
-            loadKlighdExtensionsViaServiceLoader();
-        }
-
-        this.idSynthesisMapping = id2Synthesis;
-        this.typeSynthesisMapping = type2Syntheses;
-    }
+    private KlighdDataManager() {}
 
     /**
      * Reports an error that occurred while reading extensions.
@@ -296,8 +281,8 @@ private void loadKlighdExtensionsViaExtensionPoint() {
             final String elementName = element.getName();
             final String id = element.getAttribute(ATTRIBUTE_ID);
 
-            // 'wrapper' and 'preservedProperties' extensions don't define an 'id' so check for that type of extension
-            // first before checking for a valid id
+            // 'wrapper', 'preservedProperties', and 'startupHook' extensions don't define an 'id' so check for that
+            // type of extension first before checking for a valid id
             if (ELEMENT_WRAPPER.equals(elementName)) {
                 registerCustomFigureWrapper(element);
 
@@ -309,6 +294,16 @@ private void loadKlighdExtensionsViaExtensionPoint() {
                             }
                         });
 
+            } else if (ELEMENT_STARTUP_HOOK.equals(elementName)) {
+                doRegisterExtension(element, IKlighdStartupHook.class,
+                        (startupHook) -> {
+                            try {
+                                startupHook.execute();
+                            } catch (Throwable t) {
+                                Klighd.log(new Status(IStatus.ERROR, Klighd.PLUGIN_ID, STARTUP_HOOK_ERROR_MSG, t));
+                            }
+                        });
+
             } else if (Strings.isNullOrEmpty(id)) {
                 final String msg = "KLighD: Found element of type '" + elementName
                         + "' extending extension point '" + EXTP_ID_EXTENSIONS
@@ -384,6 +379,14 @@ private void loadKlighdExtensionsViaServiceLoader() {
                 registerPreservedProperty(property);
             }
         }
+        for (IKlighdStartupHook startupHook : ServiceLoader.load(IKlighdStartupHook.class,
+                KlighdDataManager.class.getClassLoader())) {
+            try {
+                startupHook.execute();
+            } catch (Throwable t) {
+                Klighd.log(new Status(IStatus.ERROR, Klighd.PLUGIN_ID, STARTUP_HOOK_ERROR_MSG, t));
+            }
+        }
     }
 
     private <T> void doRegisterExtension(final IConfigurationElement element,
@@ -745,62 +748,6 @@ private void loadDiagramSynthesesViaServiceLoader(Map<String, ISynthesis> idSynt
         }
     }
 
-    /**
-     * Loads the registered {@link de.cau.cs.kieler.klighd.IKlighdStartupHook} from the extension point.
-     */
-    private static final void loadStartupHooksViaExtensionPoint() {
-        final Iterable<IConfigurationElement> extensions = Iterables.filter(
-                Arrays.asList(
-                        Platform.getExtensionRegistry().getConfigurationElementsFor(EXTP_ID_STARTUP_HOOK)
-                ),
-                element -> ELEMENT_STARTUP_HOOK.equals(element.getName())
-        );
-
-        for (final IConfigurationElement element : extensions) {
-            final String id = element.getAttribute(ATTRIBUTE_ID);
-            if (Strings.isNullOrEmpty(id))
-                reportError(EXTP_ID_STARTUP_HOOK, element, ATTRIBUTE_ID, null, null);
-
-            else {
-
-                // initialize model transformation from the extension point
-                IKlighdStartupHook startupHook = null;
-                try {
-                    startupHook = (IKlighdStartupHook) element.createExecutableExtension(ATTRIBUTE_CLASS);
-
-                } catch (final CoreException exception) {
-                    Klighd.handle(
-                            new Status(IStatus.ERROR, Klighd.PLUGIN_ID,
-                                    CORE_EXCEPTION_ERROR_MSG.replace("<<CLAZZ>>",
-                                            element.getAttribute(ATTRIBUTE_CLASS)), exception));
-                }
-
-                if (startupHook != null) {
-                    try {
-                        startupHook.execute();
-                    } catch (Throwable t) {
-                        Klighd.log(new Status(IStatus.ERROR, Klighd.PLUGIN_ID, STARTUP_HOOK_ERROR_MSG, t));
-                    }
-                }
-            }
-        }
-    }
-
-    /**
-     * Loads the registered {@link de.cau.cs.kieler.klighd.IKlighdStartupHook} via Java {@link ServiceLoader}.
-     */
-    private static void loadStartupHooksViaServiceLoader() {
-
-        for (IKlighdStartupHook startupHook : ServiceLoader.load(IKlighdStartupHook.class,
-                KlighdDataManager.class.getClassLoader())) {
-            try {
-                startupHook.execute();
-            } catch (Throwable t) {
-                Klighd.log(new Status(IStatus.ERROR, Klighd.PLUGIN_ID, STARTUP_HOOK_ERROR_MSG, t));
-            }
-        }
-    }
-
     private void registerDiagramSynthesisClass(final String id,
             Class<? extends AbstractDiagramSynthesis<?>> clazz, boolean wrapWithReinitializer,
                     Map<String, ISynthesis> idSynthesisMapping,