Added support for "Log" in mod.json

ModTek/Features/Logging/LoggingFeature.cs

@@ -13,7 +13,7 @@ internal static class LoggingFeature
 
     private static AppenderUnityConsole _consoleLog;
     private static AppenderFile _mainLog;
-    private static AppenderFile[] _logsAppenders = Array.Empty<AppenderFile>();
+    private static AppenderFile[] _logsAppenders = [];
 
     private static MTLoggerAsyncQueue _queue;
 
@@ -76,6 +76,16 @@ internal static void AddAppenders(string basePath, Dictionary<string, AppenderSe
         _logsAppenders = logsAppenders;
     }
 
+    internal static void AddModLogAppender(string logPath, string loggerName)
+    {
+        var logsAppenders = new AppenderFile[_logsAppenders.Length + 1];
+        Array.Copy(_logsAppenders, logsAppenders, _logsAppenders.Length);
+        var index = _logsAppenders.Length;
+        var settings = new AppenderSettings { Includes = [new FilterSettings { LoggerNames = [loggerName] }] };
+        logsAppenders[index] = new AppenderFile(logPath, settings);
+        _logsAppenders = logsAppenders;
+    }
+
     // used for intercepting all logging attempts and to log centrally
     internal static void LogAtLevel(string loggerName, LogLevel logLevel, object message, Exception exception, IStackTrace location)
     {

ModTek/Features/Manifest/Mods/ModDefExLoading.cs

@@ -20,6 +20,11 @@ internal static bool LoadMod(ModDefEx modDef, out string reason)
 
         // setup logs before calling the assembly
         LoggingFeature.AddAppenders(modDef.Directory, modDef.Logs);
+        if (modDef.Log != null)
+        {
+            var logPath = Path.Combine(modDef.Directory, modDef.Log.FilePath);
+            LoggingFeature.AddModLogAppender(logPath, modDef.Log.LoggerName);
+        }
 
         // load the mod assembly
         if (modDef.DLL != null && !LoadAssemblyAndCallInit(modDef))

ModTek/Features/Manifest/Public/ModDefEx.cs

@@ -122,10 +122,25 @@ public override bool Equals(object obj)
     // these will be different depending on the mod obviously
     public JObject Settings { get; set; } = new();
 
+    // TODO to be removed in the future or kept undocumented
+    // complex setup of log files, same complexity as ModTek itself
     [JsonProperty]
     internal const string Logs_Description = "Allows to define logs, the `key` specifies the log file path relative to `the mods directory`.";
     [JsonProperty]
     internal Dictionary<string, AppenderSettings> Logs { get; set; }
+
+    // simplified dedicated log file setup for mods
+    [JsonProperty]
+    internal const string Log_Description = "Allows to define a log relative to the mods directory, that will contain a copy of all log statements for the specified logger.";
+    [JsonProperty]
+    internal ModLogSettings Log { get; set; }
+    internal class ModLogSettings
+    {
+        [JsonProperty(Required = Required.Always)]
+        internal string FilePath { get; set; }
+        [JsonProperty(Required = Required.Always)]
+        internal string LoggerName { get; set; }
+    }
 
     [JsonIgnore]
     public bool LoadFail { get; set; }
@@ -141,7 +156,7 @@ internal void SaveState()
         var modStatePath = Path.Combine(Directory, ModTek.MOD_STATE_JSON_NAME);
         var state = new ModState();
         state.Enabled = Enabled;
-        Log.Main.Info?.Log("\t\twriting to FS:" + QuotedName + "->" + state.Enabled);
+        global::ModTek.Log.Main.Info?.Log("\t\twriting to FS:" + QuotedName + "->" + state.Enabled);
         state.SaveToPath(modStatePath);
     }
 

doc/LOGGING.md

@@ -6,7 +6,7 @@ ModTek logging has the following features:
 - Provides filter options to determine what does or does not get into the log.
 - Formats a log message so that it includes a logger name, nicely formatted time, thread id if not on main thread, log message and possibly an exception.
 - Uses a high precision timer, to allow 1/10 of microsecond precision (10^-7) for time stamps instead of milliseconds (10^-3).
-- Supports adding additional log files. (TODO allow mods to define the log files directly in mod.json, right now only possible via `ModTek/config.json`)
+- Supports adding additional log files through `ModTek/config.json`.
 - Added more log levels, use "200" for Trace logging and "250" for Fatal logging. In C# enums are ints, so casting a integer to HBS' LogLevel is valid, `(LogLevel)200`.
 - Log rotation per game start. Logs are rotated to survive at least one other start, logs that end with `.1` are from a previous application start.
 
@@ -68,8 +68,26 @@ In the advanced merge json example from before, set 200 as the log level for you
 }
 ```
 
+### Mod Local Logs
+
+> **Note**
+> It is not recommended to use this feature as it produces duplicate IO
+
+If a mod author wants to have a separate copy of all logs a logger produces, one can enable a separate log in `mod.json`:
+```json
+{
+  "Log": {
+    "FilePath": "log.txt",
+    "LoggerName": "YourMod"
+  }
+}
+```
+
 ### Nullable loggers
 
+> **Note**
+> Nullable loggers is an advanced feature only necesary if one takes the time to use it
+
 Another way of enhancing performance is using nullable loggers. This is only for advanced users requiring lots of performance while still wanting readable code.
 
 In C# one can use Null-conditional operators to check for null and skip code from executing.
@@ -109,3 +127,4 @@ if (nullableLogger != null)
 There is a caveat, the game changes log levels after the mods have initialized, so in order to keep up there is a Harmony patch required and some boilerplate code.
 
 For the boilerplate code, see [NullableLogger.cs](../ModTek/NullableLogger.cs) and [Log.cs](../ModTek/Log.cs) as used by ModTek itself.
+ModTek comments out some parts in `NullableLogger.cs` and replaces them with internal calls, these would need to be reverted back.