introduce nlog with custom sink for avalonia

SharpFM.App/AvaloniaNLogSink.cs

@@ -0,0 +1,57 @@
+using System;
+using Avalonia;
+using Avalonia.Logging;
+using NLog;
+
+namespace SharpFM.App;
+
+/// <summary>
+/// Avalonia Log Sink that writes to NLog Loggers.
+/// </summary>
+public class AvaloniaNLogSink : ILogSink
+{
+    /// <summary>
+    /// AvaloniaNLogSink is always enabled.
+    /// </summary>
+    public bool IsEnabled(LogEventLevel level, string area) => true;
+
+    public void Log(LogEventLevel level, string area, object? source, string messageTemplate)
+    {
+        Log(level, area, source, messageTemplate, Array.Empty<object?>());
+    }
+
+    public void Log(LogEventLevel level, string area, object? source, string messageTemplate, params object?[] propertyValues)
+    {
+        ILogger? logger = source is not null ? LogManager.GetLogger(source.GetType().ToString())
+            : LogManager.GetLogger(typeof(AvaloniaNLogSink).ToString());
+
+        logger.Log(LogLevelToNLogLevel(level), $"{area}: {messageTemplate}", propertyValues);
+    }
+
+    private static LogLevel LogLevelToNLogLevel(LogEventLevel level)
+    {
+        return level switch
+        {
+            LogEventLevel.Verbose => LogLevel.Trace,
+            LogEventLevel.Debug => LogLevel.Debug,
+            LogEventLevel.Information => LogLevel.Info,
+            LogEventLevel.Warning => LogLevel.Warn,
+            LogEventLevel.Error => LogLevel.Error,
+            LogEventLevel.Fatal => LogLevel.Fatal,
+            _ => LogLevel.Trace,
+        };
+    }
+}
+
+public static class NLogSinkExtensions
+{
+    /// <summary>
+    /// Creates an instance of the AvaloniaNLogSink and assigns it to the global sink.
+    /// </summary>
+    public static AppBuilder LogToNLog(
+        this AppBuilder builder)
+    {
+        Avalonia.Logging.Logger.Sink = new AvaloniaNLogSink();
+        return builder;
+    }
+}

SharpFM.App/Program.cs

@@ -9,13 +9,15 @@ class Program
     // SynchronizationContext-reliant code before AppMain is called: things aren't initialized
     // yet and stuff might break.
     [STAThread]
-    public static void Main(string[] args) => BuildAvaloniaApp()
-        .StartWithClassicDesktopLifetime(args);
+    public static void Main(string[] args)
+    {
+        BuildAvaloniaApp().StartWithClassicDesktopLifetime(args);
+    }
 
     // Avalonia configuration, don't remove; also used by visual designer.
     public static AppBuilder BuildAvaloniaApp()
         => AppBuilder.Configure<App>()
             .UsePlatformDetect()
             .WithInterFont()
-            .LogToTrace();
+            .LogToNLog();
 }

SharpFM.App/nlog.config

@@ -4,17 +4,15 @@
     xsi:schemaLocation="NLog NLog.xsd"
     xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
     autoReload="true"
-    internalLogFile="c:\temp\console-example-internal.log"
+    internalLogFile="c:\temp\SharpFM-internal.log"
     internalLogLevel="Info">
 
     <!-- the targets to write to -->
     <targets>
-        <!-- write logs to file -->
-        <!-- write logs to the visual studio code "debug console" -->
+        <!-- write colorful logs to the console -->
         <target name="logconsole" xsi:type="ColoredConsole" enableAnsiOutput="true"
             layout="${time}|${uppercase:${level:padding=5}}|${mdlc:item=ScopeName}|${ndlctiming:currentScope=true}|${logger}|${message} ${exception:format=tostring:innerFormat=tostring:maxInnerExceptionLevel=2}"
             useDefaultRowHighlightingRules="true">
-            <!-- explicitly use nlog color coding with a few adjustments for consistent display -->
             <highlight-row condition="level == LogLevel.Fatal" foregroundColor="Red" />
             <highlight-row condition="level == LogLevel.Error" foregroundColor="Yellow" />
             <highlight-row condition="level == LogLevel.Warn" foregroundColor="Magenta" />
@@ -23,6 +21,7 @@
             <highlight-row condition="level == LogLevel.Trace" foregroundColor="DarkGray" />
         </target>
 
+        <!-- write logs to file in app data folder -->
         <target xsi:type="File" name="logfile"
             fileName="${specialfolder:folder=ApplicationData}\SharpFM.log"
             layout="${longdate}|${uppercase:${level:padding=5}}|${mdlc:item=ScopeName}|${ndlctiming:currentScope=true}|${logger}|${message} ${exception:format=tostring:innerFormat=tostring:maxInnerExceptionLevel=2}" />