From 9d35952949277e3ff514ba871448218763d21b1c Mon Sep 17 00:00:00 2001
From: Stephan Richter <s.richter@srsoftware.de>
Date: Sat, 10 Jan 2026 22:19:29 +0100
Subject: [PATCH] implemented event-based page-refresh for wiki pages

---
 .../umbrella/messagebus/events/WikiEvent.java | 35 +++++++++++++++++++
 .../srsoftware/umbrella/core/Constants.java   |  1 +
 frontend/src/routes/wiki/View.svelte          | 27 ++++++++++----
 wiki/build.gradle.kts                         |  1 +
 .../srsoftware/umbrella/wiki/WikiModule.java  |  8 ++++-
 5 files changed, 65 insertions(+), 7 deletions(-)
 create mode 100644 bus/src/main/java/de/srsoftware/umbrella/messagebus/events/WikiEvent.java

diff --git a/bus/src/main/java/de/srsoftware/umbrella/messagebus/events/WikiEvent.java b/bus/src/main/java/de/srsoftware/umbrella/messagebus/events/WikiEvent.java
new file mode 100644
index 0000000..20d7adb
--- /dev/null
+++ b/bus/src/main/java/de/srsoftware/umbrella/messagebus/events/WikiEvent.java
@@ -0,0 +1,35 @@
+/* © SRSoftware 2025 */
+package de.srsoftware.umbrella.messagebus.events;
+
+import de.srsoftware.umbrella.core.model.Task;
+import de.srsoftware.umbrella.core.model.UmbrellaUser;
+import de.srsoftware.umbrella.core.model.WikiPage;
+
+import java.util.Map;
+
+import static de.srsoftware.umbrella.core.Constants.TASK;
+import static de.srsoftware.umbrella.core.Constants.WIKI;
+
+
+public class WikiEvent extends Event<WikiPage>{
+	public WikiEvent(UmbrellaUser initiator, WikiPage page, EventType type){
+		super(initiator, WIKI, page, type);
+	}
+
+	public WikiEvent(UmbrellaUser initiator, WikiPage page, Map<String, Object> oldData){
+		super(initiator, WIKI, page, oldData);
+	}
+
+	@Override
+	public String describe() {
+		return diff().orElse("[TODO: WikiEvent.describe()]");
+	}
+
+	@Override
+	public boolean isIntendedFor(UmbrellaUser user) {
+		for (var member : payload().members().values()){
+			if (member.user().equals(user)) return true;
+		}
+		return false;
+	}
+}
diff --git a/core/src/main/java/de/srsoftware/umbrella/core/Constants.java b/core/src/main/java/de/srsoftware/umbrella/core/Constants.java
index 6804d29..1ba584e 100644
--- a/core/src/main/java/de/srsoftware/umbrella/core/Constants.java
+++ b/core/src/main/java/de/srsoftware/umbrella/core/Constants.java
@@ -160,4 +160,5 @@ public class Constants {
 	public static final String VERSION = "version";
 	public static final String VERSIONS = "versions";
 
+	public static final String WIKI = "wiki";
 }
diff --git a/frontend/src/routes/wiki/View.svelte b/frontend/src/routes/wiki/View.svelte
index 56dbeee..09c51fe 100644
--- a/frontend/src/routes/wiki/View.svelte
+++ b/frontend/src/routes/wiki/View.svelte
@@ -1,7 +1,7 @@
 <script>
     import { onMount }       from 'svelte';
     import { useTinyRouter } from 'svelte-tiny-router';
-    import { api }           from '../../urls.svelte';
+    import { api, eventStream } from '../../urls.svelte';
     import { error, yikes }  from '../../warn.svelte';
     import { t }             from '../../translations.svelte';
     import { user }          from '../../user.svelte';
@@ -13,6 +13,7 @@
     import TagList           from '../tags/TagList.svelte';
 
     let detail = $state(false);
+	let eventSource      = null;
     let { key, version } = $props();
     let page = $state({});
     let router = useTinyRouter();
@@ -27,6 +28,10 @@
         return patch({members:newMembers});
     }
 
+    function connectToBus(){
+		eventSource = eventStream(null,handleUpdateEvent,null);
+    }
+
     async function dropMember(member){
         var id = member.user.id;
         let newMembers = JSON.parse(JSON.stringify(page.members));
@@ -51,6 +56,11 @@
         }
     }
 
+    function handleUpdateEvent(evt){
+        let json = JSON.parse(evt.data);
+        if (json.wikipage) loadContent(json.wikipage);
+    }
+
     function nonMember(json){
         return !page.members[json.id];
     }
@@ -70,11 +80,15 @@
         }
     }
 
-    async function loadContent(res){
+    function loadContent(json){
+        json.versions.sort((a,b)=>b-a);
+        page = { ...json };
+    }
+
+    async function loadJson(res){
         if (res.ok){
             let json  = await res.json();
-            json.versions.sort((a,b)=>b-a);
-            page = { ...json };
+            loadContent(json);
             yikes();
             return true;
         } else {
@@ -88,7 +102,7 @@
         if (version) path += `/version/${version}`;
         const url = api(path);
         const res = await fetch(url,{credentials:'include'});
-        loadContent(res);
+        loadJson(res);
     }
 
     function onclick(e){
@@ -105,7 +119,7 @@
             method:'PATCH',
             body:JSON.stringify(data)
         });
-        return loadContent(res);
+        return loadJson(res);
     }
 
     async function patchGuestPermissions(ev){
@@ -130,6 +144,7 @@
     }
 
     $effect(loadPage);
+	onMount(connectToBus);
 </script>
 {#if page && page.versions}
 <div class="wiki page">
diff --git a/wiki/build.gradle.kts b/wiki/build.gradle.kts
index bc92fdf..fccd08a 100644
--- a/wiki/build.gradle.kts
+++ b/wiki/build.gradle.kts
@@ -1,5 +1,6 @@
 description = "Umbrella : Wiki"
 
 dependencies{
+    implementation(project(":bus"))
     implementation(project(":core"))
 }
\ No newline at end of file
diff --git a/wiki/src/main/java/de/srsoftware/umbrella/wiki/WikiModule.java b/wiki/src/main/java/de/srsoftware/umbrella/wiki/WikiModule.java
index b0a6f5b..17217a1 100644
--- a/wiki/src/main/java/de/srsoftware/umbrella/wiki/WikiModule.java
+++ b/wiki/src/main/java/de/srsoftware/umbrella/wiki/WikiModule.java
@@ -11,6 +11,7 @@ import static de.srsoftware.umbrella.core.exceptions.UmbrellaException.*;
 import static de.srsoftware.umbrella.core.model.Permission.EDIT;
 import static de.srsoftware.umbrella.core.model.Permission.READ_ONLY;
 import static de.srsoftware.umbrella.wiki.Constants.*;
+import static de.srsoftware.umbrella.messagebus.MessageBus.messageBus;
 
 import com.sun.net.httpserver.HttpExchange;
 import de.srsoftware.configuration.Configuration;
@@ -20,6 +21,8 @@ import de.srsoftware.umbrella.core.BaseHandler;
 import de.srsoftware.umbrella.core.api.WikiService;
 import de.srsoftware.umbrella.core.exceptions.UmbrellaException;
 import de.srsoftware.umbrella.core.model.*;
+import de.srsoftware.umbrella.messagebus.events.WikiEvent;
+
 import java.io.IOException;
 import java.util.Arrays;
 import java.util.Optional;
@@ -190,10 +193,13 @@ public class WikiModule extends BaseHandler implements WikiService {
 	private boolean patchPage(Path path, UmbrellaUser user, HttpExchange ex) throws IOException {
 		var id = path.pop();
 		var page = loadPage(id, null);
+		var old = page.toMap();
 		var member = page.members().get(user.id());
 		if (member == null || member.permission() != EDIT) throw forbidden("You are not allowed to edit {0}!",id);
 		var json = json(ex);
-		return sendContent(ex,wikiDb.save(page.patch(json, userService())));
+		page = wikiDb.save(page.patch(json, userService()));
+		messageBus().dispatch(new WikiEvent(user,page,old));
+		return sendContent(ex,page);
 	}
 
     private boolean postNewPage(String title, UmbrellaUser user, HttpExchange ex) throws IOException {