Fix NREs in DiscordService.

Handle the client being null. Previously, a service could be created with a null client. This would leads to NREs when invoking the static Update methods. Now we provide a static helper to get the instance created for the mod. This avoids two instances of the DiscordService being created (a static one, and an instance created in the mod manifest).

OpenRA.Mods.Common/DiscordService.cs

@@ -33,28 +33,9 @@ public sealed class DiscordService : IGlobalModData, IDisposable
 	{
 		public readonly string ApplicationId = null;
 		public readonly string Tooltip = "Open Source real-time strategy game engine for early Westwood titles.";
-		DiscordRpcClient client;
+		readonly DiscordRpcClient client;
 		DiscordState currentState;
 
-		static DiscordService instance;
-		static DiscordService Service
-		{
-			get
-			{
-				if (instance != null)
-					return instance;
-
-				if (!Game.Settings.Game.EnableDiscordService)
-					return null;
-
-				if (!Game.ModData.Manifest.Contains<DiscordService>())
-					return null;
-
-				instance = Game.ModData.Manifest.Get<DiscordService>();
-				return instance;
-			}
-		}
-
 		public DiscordService(MiniYaml yaml)
 		{
 			FieldLoader.Load(this, yaml);
@@ -100,12 +81,12 @@ void OnJoin(object sender, JoinMessage args)
 			Game.RunAfterTick(() => Game.RemoteDirectConnect(new ConnectionTarget(server[0], Exts.ParseInt32Invariant(server[1]))));
 		}
 
-		void SetStatus(DiscordState state, string details = null, string secret = null, int? players = null, int? slots = null)
+		public void UpdateStatus(DiscordState state, string details = null, string secret = null, int? players = null, int? slots = null)
 		{
-			if (currentState == state)
+			if (client == null)
 				return;
 
-			if (instance == null)
+			if (currentState == state)
 				return;
 
 			string stateText;
@@ -190,8 +171,11 @@ void SetStatus(DiscordState state, string details = null, string secret = null,
 			currentState = state;
 		}
 
-		void UpdateParty(int players, int slots)
+		public void UpdatePlayers(int players, int slots)
 		{
+			if (client == null)
+				return;
+
 			if (client.CurrentPresence.Party != null)
 			{
 				client.UpdatePartySize(players, slots);
@@ -206,29 +190,26 @@ void UpdateParty(int players, int slots)
 			});
 		}
 
-		public void Dispose()
+		public void UpdateDetails(string details)
 		{
-			if (client != null)
-			{
-				client.Dispose();
-				client = null;
-				instance = null;
-			}
-		}
+			if (client == null)
+				return;
 
-		public static void UpdateStatus(DiscordState state, string details = null, string secret = null, int? players = null, int? slots = null)
-		{
-			Service?.SetStatus(state, details, secret, players, slots);
+			client.UpdateDetails(details);
 		}
 
-		public static void UpdatePlayers(int players, int slots)
+		public void Dispose()
 		{
-			Service?.UpdateParty(players, slots);
+			client?.Dispose();
 		}
 
-		public static void UpdateDetails(string details)
+		public static DiscordService Get(ModData modData)
 		{
-			Service?.client.UpdateDetails(details);
+			var manifest = modData.Manifest;
+			if (manifest.Contains<DiscordService>())
+				return manifest.Get<DiscordService>();
+			else
+				return null;
 		}
 	}
 }

OpenRA.Mods.Common/Widgets/Logic/Ingame/IngameMenuLogic.cs

@@ -583,7 +583,7 @@ void OnConfirm()
 							Game.LoadShellMap();
 						else
 						{
-							DiscordService.UpdateStatus(DiscordState.InMapEditor);
+							DiscordService.Get(modData)?.UpdateStatus(DiscordState.InMapEditor);
 							Game.LoadEditor(map);
 						}
 					}

OpenRA.Mods.Common/Widgets/Logic/Lobby/LobbyLogic.cs

@@ -855,6 +855,10 @@ void UpdatePlayerList()
 
 		void UpdateDiscordStatus()
 		{
+			var discordService = DiscordService.Get(modData);
+			if (discordService == null)
+				return;
+
 			var numberOfPlayers = 0;
 			var slots = 0;
 
@@ -889,15 +893,15 @@ void UpdateDiscordStatus()
 
 				var state = skirmishMode ? DiscordState.InSkirmishLobby : DiscordState.InMultiplayerLobby;
 
-				DiscordService.UpdateStatus(state, details, secret, numberOfPlayers, slots);
+				discordService.UpdateStatus(state, details, secret, numberOfPlayers, slots);
 				updateDiscordStatus = false;
 			}
 			else
 			{
 				if (!skirmishMode)
-					DiscordService.UpdatePlayers(numberOfPlayers, slots);
+					discordService.UpdatePlayers(numberOfPlayers, slots);
 
-				DiscordService.UpdateDetails(details);
+				discordService.UpdateDetails(details);
 			}
 		}
 
@@ -930,7 +934,7 @@ void OnGameStart()
 
 			var state = skirmishMode ? DiscordState.PlayingSkirmish : DiscordState.PlayingMultiplayer;
 			var details = map.Title + " - " + orderManager.LobbyInfo.GlobalSettings.ServerName;
-			DiscordService.UpdateStatus(state, details);
+			DiscordService.Get(modData)?.UpdateStatus(state, details);
 
 			onStart();
 		}

OpenRA.Mods.Common/Widgets/Logic/MainMenuLogic.cs

@@ -57,7 +57,7 @@ void SwitchMenu(MenuType type)
 		{
 			menuType = type;
 
-			DiscordService.UpdateStatus(DiscordState.InMenu);
+			DiscordService.Get(modData)?.UpdateStatus(DiscordState.InMenu);
 
 			// Update button mouseover
 			Game.RunAfterTick(Ui.ResetTooltips);
@@ -286,7 +286,7 @@ void OnSysInfoComplete()
 
 			Game.OnShellmapLoaded += OpenMenuBasedOnLastGame;
 
-			DiscordService.UpdateStatus(DiscordState.InMenu);
+			DiscordService.Get(modData)?.UpdateStatus(DiscordState.InMenu);
 		}
 
 		void LoadAndDisplayNews(WebServices webServices, Widget newsBG)
@@ -366,11 +366,11 @@ void OnRemoteDirectConnect(ConnectionTarget endpoint)
 			});
 		}
 
-		static void LoadMapIntoEditor(string uid)
+		void LoadMapIntoEditor(string uid)
 		{
 			Game.LoadEditor(uid);
 
-			DiscordService.UpdateStatus(DiscordState.InMapEditor);
+			DiscordService.Get(modData)?.UpdateStatus(DiscordState.InMapEditor);
 
 			lastGameState = MenuPanel.MapEditor;
 		}

OpenRA.Mods.Common/Widgets/Logic/MissionBrowserLogic.cs

@@ -219,7 +219,7 @@ void OnGameStart()
 		{
 			Ui.CloseWindow();
 
-			DiscordService.UpdateStatus(DiscordState.PlayingCampaign);
+			DiscordService.Get(modData)?.UpdateStatus(DiscordState.PlayingCampaign);
 
 			onStart();
 		}

OpenRA.Mods.Common/Widgets/Logic/MultiplayerLogic.cs

@@ -20,13 +20,16 @@ public class MultiplayerLogic : ChromeLogic
 	{
 		static readonly Action DoNothing = () => { };
 
+		readonly ModData modData;
 		readonly Action onStart;
 		readonly Action onExit;
 		readonly ServerListLogic serverListLogic;
 
 		[ObjectCreator.UseCtor]
 		public MultiplayerLogic(Widget widget, ModData modData, Action onStart, Action onExit, ConnectionTarget directConnectEndPoint)
 		{
+			this.modData = modData;
+
 			// MultiplayerLogic is a superset of the ServerListLogic
 			// but cannot be a direct subclass because it needs to pass object-level state to the constructor
 			serverListLogic = new ServerListLogic(widget, modData, Join);
@@ -96,7 +99,7 @@ void OnLobbyExit()
 
 				Game.Disconnect();
 
-				DiscordService.UpdateStatus(DiscordState.InMenu);
+				DiscordService.Get(modData)?.UpdateStatus(DiscordState.InMenu);
 			}
 
 			Game.OpenWindow("SERVER_LOBBY", new WidgetArgs

OpenRA.Mods.Common/Widgets/Logic/ReplayBrowserLogic.cs

@@ -777,7 +777,7 @@ void WatchReplay()
 			{
 				cancelLoadingReplays = true;
 
-				DiscordService.UpdateStatus(DiscordState.WatchingReplay);
+				DiscordService.Get(modData)?.UpdateStatus(DiscordState.WatchingReplay);
 
 				Game.JoinReplay(selectedReplay.FilePath);
 			}