Notified whenever a connection joins or leaves a Room.
A RoomRegistry supplies one to every room it creates so it can
maintain a reverse connection → rooms index. Membership changes are the
only way that index can be kept accurate, because application code holds the
WebSocketRoom directly (ws.room('lobby').add(conn)) and never
goes back through the registry to join.
Notified whenever a connection joins or leaves a
Room.A
RoomRegistrysupplies one to every room it creates so it can maintain a reverseconnection → roomsindex. Membership changes are the only way that index can be kept accurate, because application code holds theWebSocketRoomdirectly (ws.room('lobby').add(conn)) and never goes back through the registry to join.Since
0.2.0