public async Task <ActionResult <Participant> > PostJoinParticipantToRoomAsync([FromRoute] int roomId, [Bind(ParticipantController.ParticipantBindingFilter)] Participant participant, CancellationToken cancellationToken) { participant.RoomId = roomId; if (!await _context.Rooms.AnyAsync(x => x.Id == roomId)) { return(BadRequest()); } _context.Participants.Add(participant); await _context.SaveChangesAsync(cancellationToken); await _voteHub.ParticipantJoined(participant, cancellationToken); return(participant); }