Log Class

Namespace: Yubico.Core.Logging Assembly: Yubico.Core.dll

The Log class provides centralized logging support for your application or library. It allows you to configure logging either through a JSON configuration file (appsettings.json) or by dynamically setting up a logger using the ConfigureLoggerFactory(Action<ILoggingBuilder>) method.

How to enable Logging:

There are two primary ways to enable logging:

• 1. Add an appsettings.json to your project.
• 2. Use the ConfigureLoggerFactory(Action<ILoggingBuilder>) method.

Option 1: Using appsettings.json

Place an appsettings.json file in your project directory with the following structure:

{
  "Logging": {
    "LogLevel": {
      "Yubico.Core": "Warning",
      "Yubico.Yubikey": "Information"
    }
  }
}

Option 2: Using ConfigureLoggerFactory

Configure the logger dynamically in your code:

// Optionally, clear previous loggers
Log.ConfigureLoggerFactory(builder => builder.ClearProviders());

// Add a console logger (added by default)
Log.ConfigureLoggerFactory(builder => builder.AddConsole());

// Add a Serilog logger
Log.ConfigureLoggerFactory(builder => builder.AddSerilog());

// Add both Console and Serilog loggers
Log.ConfigureLoggerFactory(builder => builder.AddConsole().AddSerilog());

Using the Logger

After configuring the logger, you can create log instances and log messages as follows:

namespace Yubico;
public class ExampleClass
{
    public ExampleClass()
    {
        // Logger with the class name as the category
        ILogger typeNamedLogger = Log.GetLogger<ExampleClass>();
        typeNamedLogger.LogInformation("Hello World");
        // Output: Yubico.ExampleClass: Hello World

        // Logger with a custom category name
        ILogger categoryLogger = Log.GetLogger("SmartCard");
        categoryLogger.LogInformation("Hello World");
        // Output: SmartCard: Hello World
    }
}

Note:

You can also directly set a custom logger factory using the Instance property, though it is not the recommended approach. Using ConfigureLoggerFactory(Action<ILoggingBuilder>) or the appsettings.json approach is preferred.

C#

public static class Log

Inheritance object Log

Properties

Name	Description
Instance	Gets or sets the global ILoggerFactory instance used for logging throughout the application. By default, it's instantiated by using the Logging-section in your appsettings.jsonfile. Refer to the Log class for additional information.
LoggerFactory

Methods

Name	Description
ConfigureLoggerFactory(Action<ILoggingBuilder>)	From your project, you can set up logging dynamically like this, if you don't use this, the default dotnet LoggerFactory will be created and output to the console. Logging.ConfigureLoggerFactory(builder => builder.AddConsole().SetMinimumLevel(LogLevel.Trace)); With the default logging factory, you can load config using json.
GetLogger()
GetLogger(string)	Creates a new ILogger instance using the full name of the given type.
GetLogger<T>()	Creates a new ILogger instance using the full name of the given type.