implemented transaction propagation via event bus

Signed-off-by: Stephan Richter <s.richter@srsoftware.de>

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

@@ -65,7 +65,7 @@ public class MessageApi extends BaseHandler{
 		}
 	}
 
-	private void sendEvent(PrintWriter out, Event event) {
+	private void sendEvent(PrintWriter out, Event<?> event) {
 		if (event == null) return;
 		out.print("event: ");
 		out.println(event.eventType());

bus/src/main/java/de/srsoftware/umbrella/messagebus/events/TransactionEvent.java

@@ -0,0 +1,44 @@
+package de.srsoftware.umbrella.messagebus.events;
+
+import de.srsoftware.umbrella.core.ModuleRegistry;
+import de.srsoftware.umbrella.core.constants.Module;
+import de.srsoftware.umbrella.core.constants.Text;
+import de.srsoftware.umbrella.core.model.Transaction;
+import de.srsoftware.umbrella.core.model.Translatable;
+import de.srsoftware.umbrella.core.model.UmbrellaUser;
+import de.srsoftware.umbrella.core.model.UnTranslatable;
+
+import java.util.Collection;
+import java.util.List;
+
+import static de.srsoftware.umbrella.core.ModuleRegistry.accountingService;
+import static de.srsoftware.umbrella.core.model.Translatable.t;
+
+public class TransactionEvent extends Event<Transaction> {
+	private Collection<UmbrellaUser> audience;
+
+	public TransactionEvent(UmbrellaUser initiator, Transaction transaction, EventType type) {
+		super(initiator, Module.ACCOUNTING, transaction, type);
+		audience = null;
+	}
+
+	@Override
+	public Collection<UmbrellaUser> audience() {
+		if (audience == null) audience = accountingService().loadAccount(payload().accountId()).userMap().values();
+		return audience;
+	}
+
+	@Override
+	public Translatable describe() {
+		return new UnTranslatable(payload().purpose());
+	}
+
+	@Override
+	public Translatable subject() {
+		return switch (eventType()){
+			case CREATE -> t("user_created_entity",initiator().name(), Text.TRANSACTION);
+			case UPDATE -> t("user_updated_entity",initiator().name(), Text.TRANSACTION);
+			case null, default -> t("TODO"); // TODO
+		};
+	}
+}