making all references to EventBusListeners pointers

adding a keepalive event type.

backend/pkg/event_bus/event_bus.go

@@ -29,13 +29,23 @@ func GetEventBusServer(logger logrus.FieldLogger) *EventBus {
 			singletonEventBusInstance = &EventBus{
 				Logger:             logger,
 				Message:            make(chan EventBusMessage),
-				NewListener:        make(chan EventBusListener),
+				NewListener:        make(chan *EventBusListener),
-				ClosedListener:     make(chan EventBusListener),
+				ClosedListener:     make(chan *EventBusListener),
-				TotalRoomListeners: make(map[string][]EventBusListener),
+				TotalRoomListeners: make(map[string][]*EventBusListener),
 			}
 
 			// Start processing requests
 			go singletonEventBusInstance.listen()
+
+			//background keep-alive for testing
+			//go func() {
+			//	for {
+			//		time.Sleep(time.Second * 10)
+			//		// Send current time
+			//		singletonEventBusInstance.PublishMessage(models.NewEventKeepAlive("keep-alive"))
+			//	}
+			//}()
+
 		} else {
 			fmt.Println("Single instance already created.")
 		}
@@ -55,13 +65,13 @@ type EventBus struct {
 	Message chan EventBusMessage
 
 	// New client connections
-	NewListener chan EventBusListener
+	NewListener chan *EventBusListener
 
 	// Closed client connections
-	ClosedListener chan EventBusListener
+	ClosedListener chan *EventBusListener
 
 	// Total client connections
-	TotalRoomListeners map[string][]EventBusListener
+	TotalRoomListeners map[string][]*EventBusListener
 }
 
 type EventBusListener struct {
@@ -84,7 +94,7 @@ func (bus *EventBus) listen() {
 		case listener := <-bus.NewListener:
 			//check if this userId room already exists, or create it
 			if _, exists := bus.TotalRoomListeners[listener.UserID]; !exists {
-				bus.TotalRoomListeners[listener.UserID] = []EventBusListener{}
+				bus.TotalRoomListeners[listener.UserID] = []*EventBusListener{}
 			}
 			bus.TotalRoomListeners[listener.UserID] = append(bus.TotalRoomListeners[listener.UserID], listener)
 			log.Printf("Listener added to room: `%s`. %d registered listeners", listener.UserID, len(bus.TotalRoomListeners[listener.UserID]))

backend/pkg/models/event.go

@@ -3,6 +3,7 @@ package models
 type EventSourceSyncStatus string
 
 const (
+	EventTypeKeepAlive      EventSourceSyncStatus = "keep_alive"
 	EventTypeSourceSync     EventSourceSyncStatus = "source_sync"
 	EventTypeSourceComplete EventSourceSyncStatus = "source_complete"
 )

backend/pkg/models/event_keep_alive.go

@@ -0,0 +1,18 @@
+package models
+
+import "time"
+
+type EventKeepAlive struct {
+	*Event `json:",inline"`
+	Time   string `json:"time"`
+}
+
+func NewEventKeepAlive(userID string) *EventKeepAlive {
+	return &EventKeepAlive{
+		Event: &Event{
+			UserID:    userID,
+			EventType: EventTypeKeepAlive,
+		},
+		Time: time.Now().Format("2006-01-02 15:04:05"),
+	}
+}

backend/pkg/web/handler/server_sent_event.go

@@ -23,7 +23,7 @@ func SSEStream(c *gin.Context) {
 		log.Printf("could not get client channel from context")
 		return
 	}
-	listener, ok := v.(event_bus.EventBusListener)
+	listener, ok := v.(*event_bus.EventBusListener)
 	if !ok {
 		return
 	}

backend/pkg/web/middleware/server_sent_event.go

@@ -41,15 +41,15 @@ func SSEEventBusServerMiddleware(logger *logrus.Entry) gin.HandlerFunc {
 		}
 
 		// Send new connection to event server
-		bus.NewListener <- clientListener
+		bus.NewListener <- &clientListener
 
 		defer func() {
 			// Send closed connection to event server
-			bus.ClosedListener <- clientListener
+			bus.ClosedListener <- &clientListener
 		}()
 
-		c.Set(pkg.ContextKeyTypeSSEEventBusServer, bus)
+		c.Set(pkg.ContextKeyTypeSSEEventBusServer, &bus)
-		c.Set(pkg.ContextKeyTypeSSEClientChannel, clientListener)
+		c.Set(pkg.ContextKeyTypeSSEClientChannel, &clientListener)
 
 		c.Next()
 	}

frontend/src/app/services/event-bus.service.ts

@@ -37,6 +37,7 @@ export class EventBusService {
     this.authService.IsAuthenticatedSubject.subscribe((isAuthenticated) => {
       console.log("isAuthenticated changed:", isAuthenticated)
       if(isAuthenticated){
+        console.log("Started listening to event bus")
         this.eventBusSubscription = this.listenEventBus().subscribe((event: Event | EventSourceSync | EventSourceComplete)=>{
           console.log("eventbus event:", event)
           //TODO: start toasts.
@@ -48,6 +49,7 @@ export class EventBusService {
         })
       } else {
         //no longer authenticated, unsubscribe from eventbus and abort/terminate connection
+        console.log("Stopped listening to event bus")
         this.abortEventBus()
       }
     });