add websocket/Connection#IsJoined as requested at #895

websocket/connection.go

@@ -174,6 +174,9 @@ type (
 		On(string, MessageFunc)
 		// Join registers this connection to a room, if it doesn't exist then it creates a new. One room can have one or more connections. One connection can be joined to many rooms. All connections are joined to a room specified by their `ID` automatically.
 		Join(string)
+		// IsJoined returns true when this connection is joined to the room, otherwise false.
+		// It Takes the room name as its input parameter.
+		IsJoined(roomName string) bool
 		// Leave removes this connection entry from a room
 		// Returns true if the connection has actually left from the particular room.
 		Leave(string) bool
@@ -506,6 +509,10 @@ func (c *connection) Join(roomName string) {
 	c.server.Join(roomName, c.id)
 }
 
+func (c *connection) IsJoined(roomName string) bool {
+	return c.server.IsJoined(roomName, c.id)
+}
+
 func (c *connection) Leave(roomName string) bool {
 	return c.server.Leave(roomName, c.id)
 }

websocket/server.go

@@ -256,6 +256,28 @@ func (s *Server) join(roomName string, connID string) {
 	s.rooms[roomName] = append(s.rooms[roomName], connID)
 }
 
+// IsJoined reports if a specific room has a specific connection into its values.
+// First parameter is the room name, second is the connection's id.
+//
+// It returns true when the "connID" is joined to the "roomName".
+func (s *Server) IsJoined(roomName string, connID string) bool {
+	s.mu.RLock()
+	room := s.rooms[roomName]
+	s.mu.RUnlock()
+
+	if room == nil {
+		return false
+	}
+
+	for _, connid := range room {
+		if connID == connid {
+			return true
+		}
+	}
+
+	return false
+}
+
 // LeaveAll kicks out a connection from ALL of its joined rooms
 func (s *Server) LeaveAll(connID string) {
 	s.mu.Lock()