[Netcode] How can I wait until the next syncing tick, or sync network variables before calling a ClientRpc?

Questions & Answers
1

Hello, I am new to netcode, I need to make sure that my network varible _numOfConnectedClients on server is synced, or that the next tick has occured, before I call a clientRpc to run on client side. I have assigned a method to OnClientConnectedCallBack action called OnPlayerConnected, see below.

public void StartHost()
    {
        // ...other stuff here
        NetworkManager.Singleton.OnClientConnectedCallback += OnPlayerConnected;
       // ... other stuff here
        NetworkManager.Singleton.StartHost();
    }

The OnPlayerConnected calls a ClientRpc to update the number of connected clients for each client to display on ui

private void OnPlayerConnected(ulong client)
    {
        Debug.Log("NcGameManager: OnPlayerConnected Callback");
        if (IsServer) {
            _numOfConnectedClients.Value = (uint)NetworkManager.Singleton.ConnectedClients.Count;
            OnClientConnectedClientRpc(default);
        }
    }

The OnClientConnectedRpc runs on each client and updates the ui by grabbing the value from an uint network variable

    [ClientRpc]
    public void OnClientApprovedClientRpc(ClientRpcParams clientRpcParams)
    {
        Debug.Log("NcGameMan: OnClientApprovedClientRpc call");
        var connectedClientsNum = _numOfConnectedClients.Value;
        intermissionCanvas.MessageTMP.text = $"Preparing {connectedClientsNum}/4 connected 
                 players, please wait for the game to start.";
    }

The issue is, network variable is ticked 30x per sec, and hasn’t been synced when clientrpc is called. hence the number of clients connected on Client side is the previous number of clients before this client joined, or the last client that joined. So how can I force a tick, or wait until a tick has occured, before calling the clientrpc in OnPlayerConnected(ulong client)? Thanks.

2

This is a workshift, bootleg solution. Not what I was going for, but it does work on my first test try :). I’m marking this as the solution, but it may not be correct, or work in a real setup due to various issues I can’t concieve such as packets missing, or lag, but I believe it should work.

private void OnPlayerConnected(ulong client)
     {
         Debug.Log("NcGameManager: OnPlayerConnected Callback");
         if (IsServer) {
             _numOfConnectedClients.Value = (uint)NetworkManager.Singleton.ConnectedClients.Count;
             OnClientConnectedClientRpc(default);
             Invoke(nameof(OnClientApproved), 1f/NetworkManager.Singleton.NetworkTickSystem.TickRate);   
         }
     }

public void OnClientApproved()
    {
        Debug.Log("NcGameMan: OnClientApprove Invoked");
        OnClientApprovedClientRpc(default);
    }

Edit: 1f / NetworkManager.Singleton.NetworkTickSystem.TickRate did not result in a perfect scenario, so I changed to 2f / NetworkManager.Singleton.NetworkTickSystem.TickRate, In addition, you may increment the value _numOfConnectedClients.Value = (uint)NetworkManager.Singleton.ConnectedClients.Count + 1;