OO-1854: handle concurrent edit / delete of a parent message

src/main/java/org/olat/modules/fo/manager/ForumManager.java

@@ -321,6 +321,19 @@ public class ForumManager {
 		return threadList;
 	}
 	
+	public boolean existsMessageById(Long messageKey) {
+		StringBuilder query = new StringBuilder();
+		query.append("select msg.key from fomessage as msg")
+		     .append(" where msg.key=:messageKey");
+		
+		List<Long> messages = dbInstance.getCurrentEntityManager()
+				.createQuery(query.toString(), Long.class)
+				.setParameter("messageKey", messageKey)
+				.getResultList();
+		return messages == null || messages.isEmpty() || messages.get(0) == null
+				? false : messages.get(0).longValue() > -1;
+	}
+	
 	public Message getMessageById(Long messageKey) {
 		StringBuilder query = new StringBuilder();
 		query.append("select msg from fomessage as msg")

src/main/java/org/olat/modules/fo/ui/MessageEditController.java

@@ -27,6 +27,8 @@ import java.util.Collections;
 import java.util.Comparator;
 import java.util.List;
 
+import javax.persistence.PersistenceException;
+
 import org.olat.basesecurity.BaseSecurity;
 import org.olat.basesecurity.IdentityShort;
 import org.olat.core.commons.modules.bc.FolderConfig;
@@ -52,6 +54,7 @@ import org.olat.core.gui.control.generic.modal.DialogBoxController;
 import org.olat.core.gui.control.generic.modal.DialogBoxUIFactory;
 import org.olat.core.id.Identity;
 import org.olat.core.logging.AssertException;
+import org.olat.core.logging.DBRuntimeException;
 import org.olat.core.logging.activity.ThreadLocalUserActivityLogger;
 import org.olat.core.util.CodeHelper;
 import org.olat.core.util.FileUtils;
@@ -70,6 +73,7 @@ import org.olat.modules.fo.ForumChangedEvent;
 import org.olat.modules.fo.ForumLoggingAction;
 import org.olat.modules.fo.Message;
 import org.olat.modules.fo.manager.ForumManager;
+import org.olat.modules.fo.ui.events.ErrorEditMessage;
 import org.olat.user.DisplayPortraitController;
 import org.olat.util.logging.activity.LoggingResourceable;
 import org.springframework.beans.factory.annotation.Autowired;
@@ -363,6 +367,17 @@ public class MessageEditController extends FormBasicController {
 	 */
 	@Override
 	protected void formOK(UserRequest ureq) {
+		try {
+			commitMessage(ureq);
+			fireEvent(ureq, Event.DONE_EVENT);
+		} catch(DBRuntimeException | PersistenceException e) {
+			DBFactory.getInstance().rollback();
+			logError("", e);
+			fireEvent(ureq, new ErrorEditMessage());
+		}
+	}
+	
+	private void commitMessage(UserRequest ureq) {
 		// if msg exist -> persist uploads directly to final dest
 		if (message.getKey() != null) {
 			message = fm.loadMessage(message.getKey());
@@ -432,8 +447,6 @@ public class MessageEditController extends FormBasicController {
 			ThreadLocalUserActivityLogger.log(ForumLoggingAction.FORUM_REPLY_MESSAGE_CREATE, getClass(),
 					LoggingResourceable.wrap(message));
 		}
-		
-		fireEvent(ureq, Event.DONE_EVENT);
 	}
 	
 	private void notifiySubscription() {

src/main/java/org/olat/modules/fo/ui/MessageListController.java

@@ -88,6 +88,7 @@ import org.olat.modules.fo.manager.ForumManager;
 import org.olat.modules.fo.ui.MessageEditController.EditMode;
 import org.olat.modules.fo.ui.events.DeleteMessageEvent;
 import org.olat.modules.fo.ui.events.DeleteThreadEvent;
+import org.olat.modules.fo.ui.events.ErrorEditMessage;
 import org.olat.modules.fo.ui.events.SelectMessageEvent;
 import org.olat.portfolio.EPUIFactory;
 import org.olat.portfolio.manager.EPFrontendManager;
@@ -748,22 +749,30 @@ public class MessageListController extends BasicController implements GenericEve
 			}
 		} else if(editMessageCtrl == source) {
 			// edit done -> save 
-			Message message = editMessageCtrl.getMessage();
-			if(message != null) {
-				if(thread != null && thread.getKey().equals(message.getKey())) {
-					thread = message;
-				}
-				reloadModel(ureq, message);
+			if(event instanceof  ErrorEditMessage) {
+				handleEditError(ureq);
 			} else {
-				showInfo("header.cannoteditmessage");
+				Message message = editMessageCtrl.getMessage();
+				if(message != null) {
+					if(thread != null && thread.getKey().equals(message.getKey())) {
+						thread = message;
+					}
+					reloadModel(ureq, message);
+				} else {
+					showInfo("header.cannoteditmessage");
+				}
 			}
 			cmc.deactivate();
 		} else if(replyMessageCtrl == source) {
-			Message reply = replyMessageCtrl.getMessage();
-			if(reply != null) {	
-				reloadModel(ureq, reply);
+			if(event instanceof  ErrorEditMessage) {
+				handleEditError(ureq);
 			} else {
-			  	showInfo("header.cannotsavemessage");
+				Message reply = replyMessageCtrl.getMessage();
+				if(reply != null) {	
+					reloadModel(ureq, reply);
+				} else {
+				  	showInfo("header.cannotsavemessage");
+				}
 			}
 			cmc.deactivate();
 		} else if(messageTableCtrl == source) {
@@ -796,6 +805,19 @@ public class MessageListController extends BasicController implements GenericEve
 		editMessageCtrl = null;
 		cmc = null;
 	}
+	
+	private void handleEditError(UserRequest ureq) {
+		if(thread == null) {
+			fireEvent(ureq, Event.BACK_EVENT);
+			showWarning("error.message.deleted");
+		} else if(forumManager.existsMessageById(thread.getKey())) {
+			reloadModel(ureq, null);
+			showWarning("error.message.deleted");
+		} else {
+			fireEvent(ureq, Event.BACK_EVENT);
+			showWarning("error.message.deleted");
+		}
+	}
 
 	private void doReply(UserRequest ureq, MessageView parent, boolean quote) {
 		// user has clicked on button 'reply'

src/main/java/org/olat/modules/fo/ui/events/ErrorEditMessage.java

+/**
+ * <a href="http://www.openolat.org">
+ * OpenOLAT - Online Learning and Training</a><br>
+ * <p>
+ * Licensed under the Apache License, Version 2.0 (the "License"); <br>
+ * you may not use this file except in compliance with the License.<br>
+ * You may obtain a copy of the License at the
+ * <a href="http://www.apache.org/licenses/LICENSE-2.0">Apache homepage</a>
+ * <p>
+ * Unless required by applicable law or agreed to in writing,<br>
+ * software distributed under the License is distributed on an "AS IS" BASIS, <br>
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. <br>
+ * See the License for the specific language governing permissions and <br>
+ * limitations under the License.
+ * <p>
+ * Initial code contributed and copyrighted by<br>
+ * frentix GmbH, http://www.frentix.com
+ * <p>
+ */
+package org.olat.modules.fo.ui.events;
+
+import org.olat.core.gui.control.Event;
+
+/**
+ * 
+ * This error is send from MessageEditController if
+ * a database error occur.
+ * 
+ * Initial date: 01.03.2016<br>
+ * @author srosse, stephane.rosse@frentix.com, http://www.frentix.com
+ *
+ */
+public class ErrorEditMessage extends Event {
+
+	private static final long serialVersionUID = 8096812282751520199L;
+	public static final String CMD = "db-error";
+	
+	public ErrorEditMessage() {
+		super(CMD);
+	}
+
+}