NETLogger/README.md

NETLogger

NETLogger is a small logging library for .NET applications targeting .NET Standard 2.0.

Installation

Add NETLogger/NETLogger.csproj as a project reference or install the NuGet package generated during the build.

Configure the application

Configure the global logger settings once during application startup. The following example stores log files in the current user's application data directory:

using NETLogger;

LogConfiguration.MinimumLevel = LogLevel.Info;
LogConfiguration.EnableConsole = true;
LogConfiguration.EnableDebugView = true; // Windows only

string logDirectory = LogConfiguration.CreateAndGetDefaultLoggingPath("MyApplication");
LogConfiguration.GetAndSetNewLogFile(logDirectory);

Alternatively, use LogConfiguration.SetLogFile(path) to specify a complete file path. Without a configured file path, NETLogger writes only to the enabled console and Windows debug outputs.

Use a logger directly

For an independent class, create a typed Logger<T>. The type name is automatically included in each log entry as its category:

public class Service
{
	private readonly ILogger _logger = new Logger<Service>();

	public void Run()
	{
		_logger.Info("Service started.");

		try
		{
			// Application code
		}
		catch (Exception exception)
		{
			_logger.Error("Service failed.", exception);
		}
	}
}

A directly created Logger<T> can be disabled and enabled independently with Disable() and Enable(). ClearOldLogs(logsToKeep) removes old log files; without an argument, it keeps the 30 most recent files. ClearLogs() removes all log files from the configured directory.

Control multiple loggers centrally

Use a shared LoggerControlService when multiple loggers need to be enabled or disabled together. An owning class creates the service and registers its logger:

using NETLogger;
using NETLogger.Services;

public sealed class ApplicationController : IDisposable
{
	private readonly ILoggerControlService _loggerControlService;
	private readonly ILogger<ApplicationController> _logger;
	private readonly IDisposable _loggerRegistration;

	public ILoggerControlService LoggerControlService => _loggerControlService;

	public ApplicationController() : this(new LoggerControlService()) { }

	public ApplicationController(ILoggerControlService loggerControlService)
	{
		_loggerControlService = loggerControlService
			?? throw new ArgumentNullException(nameof(loggerControlService));

		_logger = NETLogger.Services.LoggerControlService.CreateAndRegisterNETLogger<ApplicationController>(
			_loggerControlService,
			out _loggerRegistration);

		_logger.Info("Application controller initialized.");
	}

	public void Dispose()
	{
		_loggerRegistration.Dispose();
	}
}

Dependent classes receive the same service and register their own typed logger. Dispose the IDisposable registration when the owning instance is disposed:

public sealed class BackgroundService : IDisposable
{
	private readonly ILogger<BackgroundService> _logger;
	private readonly IDisposable _loggerRegistration;

	public BackgroundService(ILoggerControlService loggerControlService)
	{
		_logger = LoggerControlService.CreateAndRegisterNETLogger<BackgroundService>(
			loggerControlService,
			out _loggerRegistration);

		_logger.Info("Background service initialized.");
	}

	public void Dispose()
	{
		_loggerRegistration.Dispose();
	}
}

All registered loggers can be toggled together:

loggerControlService.IsEnabled = false; // Disable all registered loggers
loggerControlService.IsEnabled = true;  // Enable all registered loggers

Initialize loggers for static members

Classes with static logging members can use explicit initialization to participate in the shared LoggerControlService:

public sealed class ConfigurationCache
{
	private static ILogger<ConfigurationCache> _logger;
	private static IDisposable _loggerRegistration;

	private ConfigurationCache() { }

	public static void InitializeLogger(ILoggerControlService loggerControlService)
	{
		if (loggerControlService == null)
			throw new ArgumentNullException(nameof(loggerControlService));

		_loggerRegistration?.Dispose();
		_logger = LoggerControlService.CreateAndRegisterNETLogger<ConfigurationCache>(
			loggerControlService,
			out _loggerRegistration);
	}
}

The owning class initializes the logger with its shared service:

ConfigurationCache.InitializeLogger(_loggerControlService);

Log levels and outputs

The available levels are Trace, Debug, Info, Warn, Error, and Fatal. Messages below LogConfiguration.MinimumLevel are ignored. Warn, Error, and Fatal optionally accept an exception:

try
{
	// Application code
}
catch (Exception exception)
{
	_logger.Error("Operation failed.", exception);
}

NETLogger can write to the Windows debug output, the console, and a UTF-8 log file at the same time.