feat(NetworkManager):Allow host client to start late or rejoin

Assets/Mirror/Core/NetworkIdentity.cs

@@ -707,9 +707,10 @@ internal void OnStopServer()
             }
         }
 
-        bool clientStarted;
+        public bool clientStarted;
         internal void OnStartClient()
         {
+            //Debug.Log($"clientStarted {connectionToClient} {clientStarted}");
             if (clientStarted) return;
 
             clientStarted = true;

Assets/Mirror/Core/NetworkManager.cs

@@ -404,7 +404,20 @@ public void StartClient()
                 return;
             }
 
-            mode = NetworkManagerMode.ClientOnly;
+            if (string.IsNullOrWhiteSpace(networkAddress))
+            {
+                Debug.LogError("Must set the Network Address field in the manager");
+                return;
+            }
+
+            if (mode == NetworkManagerMode.ServerOnly)
+            {
+                mode = NetworkManagerMode.Host;
+                FinishStartHost();
+                return;
+            }
+            else
+                mode = NetworkManagerMode.ClientOnly;
 
             SetupClient();
 
@@ -413,11 +426,6 @@ public void StartClient()
 
             RegisterClientMessages();
 
-            if (string.IsNullOrWhiteSpace(networkAddress))
-            {
-                Debug.LogError("Must set the Network Address field in the manager");
-                return;
-            }
             // Debug.Log($"NetworkManager StartClient address:{networkAddress}");
 
             NetworkClient.Connect(networkAddress);
@@ -1277,6 +1285,9 @@ void OnClientDisconnectInternal()
             // shutdown client
             NetworkClient.Shutdown();
 
+            foreach (NetworkIdentity identity in NetworkServer.spawned.Values)
+                identity.clientStarted = false;
+
             // Exit here if we're now in ServerOnly mode (StopClient called in Host mode).
             if (mode == NetworkManagerMode.ServerOnly) return;
 

Assets/Mirror/Core/NetworkManagerHUD.cs

@@ -150,9 +150,17 @@ void StopButtons()
             }
             else if (NetworkServer.active)
             {
+                GUILayout.BeginHorizontal();
+
                 // stop server if server-only
                 if (GUILayout.Button("Stop Server"))
                     manager.StopServer();
+
+                // start client if server-only, engaging host mode.
+                if (GUILayout.Button("Start Client"))
+                    manager.StartClient();
+
+                GUILayout.EndHorizontal();
             }
         }
     }