first working version with event reception in kanban

bus/src/main/java/de/srsoftware/umbrella/messagebus/Event.java

@@ -1,21 +1,26 @@
 /* © SRSoftware 2025 */
 package de.srsoftware.umbrella.messagebus;
 
-import de.srsoftware.umbrella.core.model.UmbrellaUser;
+import static de.srsoftware.umbrella.core.Constants.USER;
 
-public abstract class Event<Payload> {
+import de.srsoftware.tools.Mappable;
+import de.srsoftware.umbrella.core.model.UmbrellaUser;
+import java.util.Map;
+import org.json.JSONObject;
+
+public abstract class Event<Payload extends Mappable> {
 
 	public enum EventType {
 		CREATE,
 		UPDATE,
 		DELETE;
-	}
 
+	}
 	private UmbrellaUser initiator;
+
 	private String realm;
 	private Payload payload;
 	private EventType eventType;
-
 	public Event(UmbrellaUser initiator, String realm, Payload payload, EventType type){
 		this.initiator = initiator;
 		this.realm     = realm;
@@ -27,7 +32,21 @@ public abstract class Event<Payload> {
 		return eventType.toString();
 	}
 
-	public abstract String json();
+	public abstract boolean isIntendedFor(UmbrellaUser user);
+
+	public String json(){
+		Class<?> clazz = payload.getClass();
+		{ // get the highest superclass that is not object
+			Class<?> parent = clazz.getSuperclass();
+
+			while (parent != null && parent != Object.class) {
+				clazz = parent;
+				parent = clazz.getSuperclass();
+			}
+		}
+		var map = Map.of(USER,initiator.toMap(),clazz.getSimpleName().toLowerCase(),payload.toMap());
+		return new JSONObject(map).toString();
+	}
 
 	public Payload payload(){
 		return payload;

bus/src/main/java/de/srsoftware/umbrella/messagebus/EventQueue.java

@@ -5,7 +5,6 @@ import static de.srsoftware.umbrella.messagebus.MessageBus.messageBus;
 
 import java.net.InetSocketAddress;
 import java.util.LinkedList;
-import java.util.Objects;
 
 public class EventQueue extends LinkedList<Event> implements AutoCloseable, EventListener {
 

bus/src/main/java/de/srsoftware/umbrella/messagebus/MessageApi.java

@@ -4,6 +4,7 @@ package de.srsoftware.umbrella.messagebus;
 import static de.srsoftware.umbrella.core.Constants.*;
 import static de.srsoftware.umbrella.core.ModuleRegistry.userService;
 import static java.lang.System.Logger.Level.*;
+import static java.lang.Thread.sleep;
 import static java.net.HttpURLConnection.HTTP_OK;
 
 import com.sun.net.httpserver.HttpExchange;
@@ -13,7 +14,6 @@ import de.srsoftware.tools.SessionToken;
 import de.srsoftware.umbrella.core.BaseHandler;
 import de.srsoftware.umbrella.core.exceptions.UmbrellaException;
 import de.srsoftware.umbrella.core.model.Token;
-
 import java.io.IOException;
 import java.io.PrintWriter;
 import java.net.InetSocketAddress;
@@ -42,14 +42,16 @@ public class MessageApi extends BaseHandler{
 			LOG.log(INFO,"{0} opened event stream.",addr);
 			var counter = 0;
 			while (!stream.checkError()){
-				Thread.sleep(100);
+				sleep(100);
 				if (eventQueue.isEmpty()){
 					if (++counter > 300) counter = sendBeacon(addr,stream);
 				} else {
-					var elem = eventQueue.remove(0);
+					var event = eventQueue.removeFirst();
-					LOG.log(DEBUG,"sending event to {0}",addr);
+					//if (event.isIntendedFor(user.get())) {
-					sendEvent(stream,elem);
+						LOG.log(DEBUG, "sending event to {0}", addr);
+						sendEvent(stream, event);
 						counter = 0;
+					//}
 				}
 			}
 			LOG.log(INFO,"{0} disconnected from event stream.",addr);

bus/src/main/java/de/srsoftware/umbrella/messagebus/TaskEvent.java

@@ -5,15 +5,18 @@ import static de.srsoftware.umbrella.core.Constants.TASK;
 
 import de.srsoftware.umbrella.core.model.Task;
 import de.srsoftware.umbrella.core.model.UmbrellaUser;
-import org.json.JSONObject;
+
 
 public class TaskEvent extends Event<Task>{
 	public TaskEvent(UmbrellaUser initiator, Task task, EventType type){
-		super(initiator,TASK, task, type);
+		super(initiator, TASK, task, type);
 	}
 
 	@Override
-	public String json() {
+	public boolean isIntendedFor(UmbrellaUser user) {
-		return new JSONObject(payload().toMap()).toString();
+		for (var member : payload().members().values()){
+			if (member.user().equals(user)) return true;
+		}
+		return false;
 	}
 }

frontend/src/App.svelte

@@ -79,7 +79,7 @@
         <span class="error">{@html messages.error}</span>
         {/if}
         {#if messages.warning}
-        <span class="error">{@html messages.warning}</span>
+        <span class="warn">{@html messages.warning}</span>
         {/if}
         <Route path="/"                            component={User} />
         <Route path="/bookmark"                    component={Bookmarks} />
@@ -130,7 +130,7 @@
             <span class="error">{@html messages.error}</span>
             {/if}
             {#if messages.warning}
-            <span class="error">{@html messages.warning}</span>
+            <span class="warn">{@html messages.warning}</span>
             {/if}
             <Route path="/user/reset/pw"  component={ResetPw} />
             <Route path="/oidc_callback"  component={Callback} />

frontend/src/routes/project/Kanban.svelte

@@ -2,8 +2,8 @@
     import { onDestroy, onMount } from 'svelte';
     import { useTinyRouter } from 'svelte-tiny-router';
 
-    import { api, target }   from '../../urls.svelte.js';
+    import { api, eventStream, target }   from '../../urls.svelte.js';
-    import { error, yikes }  from '../../warn.svelte';
+    import { error, messages, yikes }  from '../../warn.svelte';
     import { t }             from '../../translations.svelte.js';
     import { user }          from '../../user.svelte.js';
 
@@ -25,6 +25,7 @@
     let tasks        = $state({});
     let users        = [];
     let columns      = $derived(project.allowed_states?Object.keys(project.allowed_states).length+1:1);
+    let info         = $state(null);
 
     let stateList = {};
     $effect(() => updateUrl(filter_input));
@@ -57,12 +58,6 @@
         return a.name.localeCompare(b.name);
     }
 
-    function connectToEventStream(){
-		eventSource = new EventSource(api('bus'));
-		eventSource.onmessage = (m) => { console.log(m); } // https://stackoverflow.com/questions/57650830/sse-onmessage-never-gets-called#comment104961222_59383080
-		eventSource.addEventListener('UPDATE', (event) => console.log(JSON.parse(event.data)) );
-    }
-
     async function create(name,user_id,state){
         var url = api('task/add');
         let task = {
@@ -120,9 +115,25 @@
         }
     }
 
+    function handleUpdateEvent(evt){
+        let json = JSON.parse(evt.data);
+        if (json.task && json.user){
+            for (let uid in tasks){
+                if (!uid) continue;
+                for (let state in tasks[uid]) delete tasks[uid][state][json.task.id];
+            }
+            processTask(json.task);
+            if (json.user.id != user.id) {
+                info = t("user_updated_entity",{user:json.user.name,entity:json.task.name});
+                setTimeout(() => { info = null; },2500);
+            }
+        }
+
+    }
+
     async function load(){
         try {
-            connectToEventStream();
+			eventSource = eventStream(handleUpdateEvent);
             await loadProject();
             loadTasks({project_id:+id,parent_task_id:0});
         } catch (ignored) {}
@@ -164,7 +175,15 @@
             var json = await resp.json();
             for (var task_id of Object.keys(json)) {
                 let task     = json[task_id];
-                if (task.no_index) continue;
+                processTask(task);
+            }
+        } else {
+            error(resp);
+        }
+    }
+
+    function processTask(task){
+			if (task.no_index) return;
 
             let state    = +task.status;
             let owner    = null;
@@ -179,11 +198,7 @@
             task.assignee = assignee;
             if (!tasks[assignee]) tasks[assignee] = {};
             if (!tasks[assignee][state]) tasks[assignee][state] = {};
-                tasks[assignee][state][task_id] = task;
+            tasks[assignee][state][task.id] = task;
-            }
-        } else {
-            error(resp);
-        }
     }
 
     function hover(ev,user_id,state){
@@ -241,7 +256,9 @@
 {#if project}
 <h1 onclick={ev => router.navigate(`/project/${project.id}/view`)}>{project.name}</h1>
 {/if}
-
+{#if info}
+<div class="info">{info}</div>
+{/if}
 {#if project}
 <fieldset class="kanban description {descr?'active':''}" onclick={e => descr = !descr}>
     <legend>{t('description')} – {t('expand_on_click')}</legend>

frontend/src/urls.svelte.js

@@ -15,6 +15,12 @@ export function drop(url){
     });
 }
 
+export function eventStream(updateHandler){
+	const es = new EventSource(api('bus'), {withCredentials: true});
+	if (updateHandler) es.addEventListener('UPDATE', updateHandler);
+	return es;
+}
+
 export function patch(url,data){
     return fetch(url,{
         credentials : 'include',

task/src/main/java/de/srsoftware/umbrella/task/TaskModule.java

@@ -314,7 +314,8 @@ public class TaskModule extends BaseHandler implements TaskService {
 		if (json.has(NEW_MEMBER) && json.get(NEW_MEMBER) instanceof Number num) addMember(task, num.longValue());
 		if (json.has(PARENT_TASK_ID) && json.get(PARENT_TASK_ID) instanceof Number ptid && newParentIsSubtask(task, ptid.longValue())) throw forbidden("Task must not be sub-task of itself.");
 		taskDb.save(task.patch(json));
-		messageBus().dispatch(new TaskEvent(user,task, UPDATE));
+		var tagList = tagService().getTags(TASK, taskId, user);
+		messageBus().dispatch(new TaskEvent(user,new TaggedTask(task,tagList), UPDATE));
 		return sendContent(ex, task);
 	}
 

translations/src/main/resources/de.json

@@ -343,6 +343,7 @@
   "user_list": "Benutzer-Liste",
   "user_module" : "Umbrella User-Verwaltung",
   "users": "Benutzer",
+  "user_updated_entity": "{user} hat \"{entity}\" bearbeitet",
 
   "website": "Website",
   "welcome" : "Willkommen, {0}",

web/src/main/resources/web/css/default-color.css

@@ -81,6 +81,11 @@ tr:hover .taglist .tag button {
   color: black;
 }
 
+.info{
+	background: orange;
+	color: black;
+}
+
 .kanban .add_task,
 .kanban .box,
 .kanban .head,

web/src/main/resources/web/css/default.css

@@ -168,6 +168,15 @@ td, tr{
   border-radius: 6px;
 }
 
+.info {
+	position: absolute;
+	bottom: 0;
+	right: 0;
+	font-size: 14px;
+	z-index: 200;
+	padding: 3px;
+}
+
 .warn {
     padding: 5px;
     border-radius: 6px;