add more handlers and some comments

reactivity/websocket.go

@@ -9,13 +9,15 @@ import (
 )
 
 // MessageReceiver receives decoded WebSocket payloads. Implemented by tether.Engine.
-type MessageReceiver interface {
+type EngineHandler interface {
+	OnConnect(conn *websocket.Conn) error
+	OnDisconnect(conn *websocket.Conn) error
 	OnReceiveMessage(msg map[string]interface{}) error
 }
 
 var upgrader = websocket.Upgrader{}
 
-func Handle(w http.ResponseWriter, r *http.Request, e MessageReceiver) {
+func Handle(w http.ResponseWriter, r *http.Request, e EngineHandler) {
 	ws, err := upgrader.Upgrade(w, r, nil)
 	if err != nil {
 		slog.Error("WS: Failed to upgrade to websocket", "error", err)
@@ -23,6 +25,13 @@ func Handle(w http.ResponseWriter, r *http.Request, e MessageReceiver) {
 	}
 	defer ws.Close()
 
+	err = e.OnConnect(ws)
+	if err != nil {
+		slog.Error("WS: Failed to call onConnect handler", "error", err)
+		return
+	}
+	defer e.OnDisconnect(ws)
+
 	for {
 		_, message, err := ws.ReadMessage()
 		if err != nil {