Merge pull request #475 from goroskob/332_Initialize_annotation_for_i…

…nitialize_ViewModel_method

Added @initialize annotation for ViewModel to define initialize method of any visibility #332

mvvmfx/src/main/java/de/saxsys/mvvmfx/Initialize.java

@@ -0,0 +1,52 @@
+/*******************************************************************************
+ * Copyright 2017 Gleb Koval
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ ******************************************************************************/
+package de.saxsys.mvvmfx;
+
+import java.lang.annotation.ElementType;
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+import java.lang.annotation.Target;
+
+/**
+ *
+ * This annotation is used to mark the method in a ViewModel to be called after all mvvmFx injections.
+ * If no method is marked, public <code>initialize()</code> method will be used, if present.<br>
+ * Example: <br>
+ * <br>
+ *
+ * <pre>
+ * public class SomeViewModel implements {@link ViewModel} {
+ *
+ *         // mvvmFx injections
+ *        {@literal @}{@link InjectScope}
+ *         private SomeScope someScope;
+ *         ...
+ *
+ *        {@literal @}Initialize
+ *         private void init() {
+ *             someScope.subscribe(...);
+ *             ...
+ *         }
+ * }
+ * </pre>
+ *
+ * @author Gleb Koval
+ *
+ */
+@Retention(RetentionPolicy.RUNTIME)
+@Target(ElementType.METHOD)
+public @interface Initialize {
+}

mvvmfx/src/main/java/de/saxsys/mvvmfx/internal/viewloader/ReflectionUtils.java

@@ -16,6 +16,7 @@
 package de.saxsys.mvvmfx.internal.viewloader;
 
 import java.lang.annotation.Annotation;
+import java.lang.reflect.AccessibleObject;
 import java.lang.reflect.Field;
 import java.security.AccessController;
 import java.security.PrivilegedAction;
@@ -89,13 +90,13 @@ public static List<Field> getFieldsFromClassHierarchy(Class<?> type) {
 
 
 	/**
-	 * Helper method to execute a callback on a given field. This method encapsulates the error handling logic and the
-	 * handling of accessibility of the field.
+	 * Helper method to execute a callback on a given member. This method encapsulates the error handling logic and the
+	 * handling of accessibility of the member.
 	 *
-	 * After the callback is executed the accessibility of the field will be reset to the originally state.
+	 * After the callback is executed the accessibility of the member will be reset to the originally state.
 	 *
-	 * @param field
-	 *            the field that is made accessible to run the callback
+	 * @param member
+	 *            the member that is made accessible to run the callback
 	 * @param callable
 	 *            the callback that will be executed.
 	 * @param errorMessage
@@ -106,19 +107,19 @@ public static List<Field> getFieldsFromClassHierarchy(Class<?> type) {
 	 * @throws IllegalStateException
 	 *             when something went wrong.
 	 */
-	public static <T> T accessField(final Field field, final Callable<T> callable, String errorMessage) {
+	public static <T> T accessMember(final AccessibleObject member, final Callable<T> callable, String errorMessage) {
 		if (callable == null) {
 			return null;
 		}
 		return AccessController.doPrivileged((PrivilegedAction<T>) () -> {
-			boolean wasAccessible = field.isAccessible();
+			boolean wasAccessible = member.isAccessible();
 			try {
-				field.setAccessible(true);
+				member.setAccessible(true);
 				return callable.call();
 			} catch (Exception exception) {
 				throw new IllegalStateException(errorMessage, exception);
 			} finally {
-				field.setAccessible(wasAccessible);
+				member.setAccessible(wasAccessible);
 			}
 		});
 	}
@@ -136,21 +137,21 @@ public static <T> T accessField(final Field field, final Callable<T> callable, S
 	 *            the new value that the field should be set to.
 	 */
 	public static void setField(final Field field, Object target, Object value) {
-		accessField(field, () -> field.set(target, value),
+		accessMember(field, () -> field.set(target, value),
 				"Cannot set the field [" + field.getName() + "] of instance [" + target + "] to value [" + value + "]");
 	}
 
 
 	/**
-	 * Helper method to execute a callback on a given field. This method encapsulates the error handling logic and the
-	 * handling of accessibility of the field. The difference to
-	 * {@link ReflectionUtils#accessField(Field, Callable, String)} is that this method takes a callback that doesn't
+	 * Helper method to execute a callback on a given member. This method encapsulates the error handling logic and the
+	 * handling of accessibility of the member. The difference to
+	 * {@link ReflectionUtils#accessMember(AccessibleObject, Callable, String)} is that this method takes a callback that doesn't
 	 * return anything but only creates a sideeffect.
 	 *
-	 * After the callback is executed the accessibility of the field will be reset to the originally state.
+	 * After the callback is executed the accessibility of the member will be reset to the originally state.
 	 *
-	 * @param field
-	 *            the field that is made accessible to run the callback
+	 * @param member
+	 *            the member that is made accessible to run the callback
 	 * @param sideEffect
 	 *            the callback that will be executed.
 	 * @param errorMessage
@@ -159,19 +160,19 @@ public static void setField(final Field field, Object target, Object value) {
 	 * @throws IllegalStateException
 	 *             when something went wrong.
 	 */
-	public static void accessField(final Field field, final SideEffect sideEffect, String errorMessage) {
+	public static void accessMember(final AccessibleObject member, final SideEffect sideEffect, String errorMessage) {
 		if (sideEffect == null) {
 			return;
 		}
-		AccessController.doPrivileged((PrivilegedAction) () -> {
-			boolean wasAccessible = field.isAccessible();
+		AccessController.doPrivileged((PrivilegedAction<?>) () -> {
+			boolean wasAccessible = member.isAccessible();
 			try {
-				field.setAccessible(true);
+				member.setAccessible(true);
 				sideEffect.call();
 			} catch (Exception exception) {
 				throw new IllegalStateException(errorMessage, exception);
 			} finally {
-				field.setAccessible(wasAccessible);
+				member.setAccessible(wasAccessible);
 			}
 			return null;
 		});

mvvmfx/src/main/java/de/saxsys/mvvmfx/internal/viewloader/ViewLoaderReflectionUtils.java

@@ -16,6 +16,7 @@
 package de.saxsys.mvvmfx.internal.viewloader;
 
 import de.saxsys.mvvmfx.Context;
+import de.saxsys.mvvmfx.Initialize;
 import de.saxsys.mvvmfx.InjectContext;
 import de.saxsys.mvvmfx.InjectScope;
 import de.saxsys.mvvmfx.InjectViewModel;
@@ -30,7 +31,6 @@
 import javax.annotation.PostConstruct;
 import java.lang.annotation.Annotation;
 import java.lang.reflect.Field;
-import java.lang.reflect.InvocationTargetException;
 import java.lang.reflect.Method;
 import java.security.AccessController;
 import java.security.PrivilegedAction;
@@ -166,7 +166,7 @@ public static <ViewType extends View<? extends ViewModelType>, ViewModelType ext
         Optional<Field> fieldOptional = getViewModelField(view.getClass(), viewModelType);
         if (fieldOptional.isPresent()) {
             Field field = fieldOptional.get();
-            return ReflectionUtils.accessField(field, () -> (ViewModelType) field.get(view),
+            return ReflectionUtils.accessMember(field, () -> (ViewModelType) field.get(view),
                     "Can't get the viewModel of type <" + viewModelType + ">");
         } else {
             return null;
@@ -189,7 +189,7 @@ public static void injectViewModel(final View view, ViewModel viewModel) {
         final Optional<Field> fieldOptional = getViewModelField(view.getClass(), viewModel.getClass());
         if (fieldOptional.isPresent()) {
             Field field = fieldOptional.get();
-            ReflectionUtils.accessField(field, () -> {
+            ReflectionUtils.accessMember(field, () -> {
                 Object existingViewModel = field.get(view);
                 if (existingViewModel == null) {
                     field.set(view, viewModel);
@@ -258,7 +258,7 @@ public static <V extends View<? extends VM>, VM extends ViewModel> void createAn
         if (fieldOptional.isPresent()) {
             Field field = fieldOptional.get();
 
-            ReflectionUtils.accessField(field, () -> {
+            ReflectionUtils.accessMember(field, () -> {
                 Object existingViewModel = field.get(view);
 
                 if (existingViewModel == null) {
@@ -294,7 +294,7 @@ static void createAndInjectScopes(Object viewModel, ContextImpl context) {
         List<Field> scopeFields = getScopeFields(viewModel.getClass());
 
         scopeFields.forEach(scopeField -> {
-            ReflectionUtils.accessField(scopeField, () -> injectScopeIntoField(scopeField, viewModel, context),
+            ReflectionUtils.accessMember(scopeField, () -> injectScopeIntoField(scopeField, viewModel, context),
                     "Can't inject Scope into ViewModel <" + viewModel.getClass() + ">");
         });
     }
@@ -305,7 +305,7 @@ public static void injectContext(View codeBehind, ContextImpl context) {
 
         if (contextField.isPresent()) {
             Field field = contextField.get();
-            ReflectionUtils.accessField(field, () -> {
+            ReflectionUtils.accessMember(field, () -> {
                 field.set(codeBehind, context);
             }, "Can't inject Context into the view <" + codeBehind + ">");
         }
@@ -372,10 +372,10 @@ public static <ViewType extends View<? extends ViewModelType>, ViewModelType ext
     }
 
     /**
-     * If a ViewModel has a method with the signature
-     * <code>public void initialize()</code> it will be invoked. If no such
-     * method is available nothing happens.
-     * 
+     * If a ViewModel has a method annotated with {@link Initialize}
+     * or method with the signature <code>public void initialize()</code>
+     * it will be invoked. If no such method is available nothing happens.
+     *
      * @param viewModel
      *            the viewModel that's initialize method (if available) will be
      *            invoked.
@@ -387,7 +387,9 @@ public static <ViewModelType extends ViewModel> void initializeViewModel(ViewMod
             return;
         }
         try {
-            final Method initMethod = viewModel.getClass().getMethod("initialize");
+            Method annotatedMethod = getInitializeMethod(viewModel);
+            // find method annotated with @Initialize or use initialize() otherwise
+            final Method initMethod = annotatedMethod != null ? annotatedMethod : viewModel.getClass().getMethod("initialize");
             // if there is a @PostConstruct annotation, throw an exception to prevent double injection
             if(initMethod.isAnnotationPresent(PostConstruct.class)) {
                 throw new IllegalStateException(String.format("initialize method of ViewModel [%s] is annotated with @PostConstruct. " +
@@ -397,19 +399,21 @@ public static <ViewModelType extends ViewModel> void initializeViewModel(ViewMod
                         "https://github.com/sialcasa/mvvmFX/wiki/Dependency-Injection#lifecycle-postconstruct", viewModel));
             }
 
-            AccessController.doPrivileged((PrivilegedAction) () -> {
-                try {
-                    return initMethod.invoke(viewModel);
-                } catch (InvocationTargetException | IllegalAccessException e) {
-                    throw new IllegalStateException(
-                            "mvvmFX wasn't able to call the initialize method of ViewModel [" + viewModel + "].", e);
-                }
-            });
+            ReflectionUtils.accessMember(initMethod, () -> initMethod.invoke(viewModel), "mvvmFX wasn't able to call the initialize method of ViewModel [" + viewModel + "].");
         } catch (NoSuchMethodException e) {
             // it's perfectly fine that a ViewModel has no initialize method.
         }
     }
 
+    private static <ViewModelType extends ViewModel> Method getInitializeMethod(ViewModelType viewModel) {
+        for (Method method : viewModel.getClass().getDeclaredMethods()) {
+            if(method.isAnnotationPresent(Initialize.class)) {
+                return method;
+            }
+        }
+        return null;
+    }
+
     /**
      * This method adds listeners for the {@link SceneLifecycle}.
      */

mvvmfx/src/test/java/de/saxsys/mvvmfx/internal/viewloader/FluentViewLoader_FxmlView_Test.java

@@ -470,4 +470,20 @@ public void testExistingViewModelWithoutInjectionInView() {
 
         assertThat(TestViewModel.wasInitialized).isFalse();
 	}
+
+	/**
+	 * Method annotated with {@link de.saxsys.mvvmfx.Initialize} annotation initializes the ViewModel
+	 * */
+	@Test
+	public void testViewModelIsInitializedWithAnnotatatedMethod() {
+		TestViewModelWithAnnotatedInitialize.wasInitialized = false;
+
+		ViewTuple<TestFxmlViewWithViewModelWithAnnotatedInitialize, TestViewModelWithAnnotatedInitialize> tuple
+				= FluentViewLoader.fxmlView(TestFxmlViewWithViewModelWithAnnotatedInitialize.class).load();
+
+		TestViewModelWithAnnotatedInitialize viewModel = tuple.getViewModel();
+
+		assertThat(TestViewModelWithAnnotatedInitialize.wasInitialized).isTrue();
+
+	}
 }

mvvmfx/src/test/java/de/saxsys/mvvmfx/internal/viewloader/example/TestFxmlViewWithViewModelWithAnnotatedInitialize.java

@@ -0,0 +1,32 @@
+/*******************************************************************************
+ * Copyright 2017 Gleb Koval
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ ******************************************************************************/
+package de.saxsys.mvvmfx.internal.viewloader.example;
+
+import de.saxsys.mvvmfx.FxmlView;
+import de.saxsys.mvvmfx.InjectViewModel;
+
+/**
+ * This class is used as example View class that uses ViewModel initialized with
+ * method annotated with {@link de.saxsys.mvvmfx.Initialize} annotation
+ *
+ * @author Gleb Koval
+ */
+public class TestFxmlViewWithViewModelWithAnnotatedInitialize implements FxmlView<TestViewModelWithAnnotatedInitialize> {
+
+	@InjectViewModel
+	private TestViewModelWithAnnotatedInitialize viewModel;
+
+}

mvvmfx/src/test/java/de/saxsys/mvvmfx/internal/viewloader/example/TestViewModelWithAnnotatedInitialize.java

@@ -0,0 +1,35 @@
+/*******************************************************************************
+ * Copyright 2017 Gleb Koval
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ ******************************************************************************/
+package de.saxsys.mvvmfx.internal.viewloader.example;
+
+import de.saxsys.mvvmfx.Initialize;
+import de.saxsys.mvvmfx.ViewModel;
+
+/**
+ * This class is used as example ViewModel class that uses init method annotated with {@link Initialize}
+ *
+ * @author Gleb Koval
+ */
+public class TestViewModelWithAnnotatedInitialize implements ViewModel {
+
+    public static boolean wasInitialized = false;
+
+	@Initialize
+    private void init() {
+        wasInitialized = true;
+    }
+
+}

mvvmfx/src/test/resources/de/saxsys/mvvmfx/internal/viewloader/example/TestFxmlViewWithViewModelWithAnnotatedInitialize.fxml

@@ -0,0 +1,6 @@
+<?xml version="1.0" encoding="UTF-8"?>
+
+<?import javafx.scene.layout.VBox?>
+<VBox xmlns:fx="http://javafx.com/fxml" fx:controller="de.saxsys.mvvmfx.internal.viewloader.example.TestFxmlViewWithViewModelWithAnnotatedInitialize">
+
+</VBox>