Add Alias attribute to NLogLoggerProvider

[leewadhams]

Added the Microsoft.Extensions.Logging.ProviderAliasAttribute to the NLogLoggerProvider to enable it to be used Logging Configuration instead of having to supply the full name of the provider class.

[304NotModified]

Hi! Could you please give an configuration example how to use this? Thanks!

[leewadhams]

The configuration would be like that of the example in the Microsoft docs on Log Filtering with the addition of specifying filters for the NLog Logging Provider using the alias NLog instead of having to specify the full name NLog.Extensions.Logging.NLogLoggerProvider e.g.

public static void Main(string[] args)
{
    var webHost = new WebHostBuilder()
        .UseKestrel()
        .UseContentRoot(Directory.GetCurrentDirectory())
        .ConfigureAppConfiguration((hostingContext, config) =>
        {
            var env = hostingContext.HostingEnvironment;
            config.AddJsonFile("appsettings.json", optional: true, reloadOnChange: true)
                  .AddJsonFile($"appsettings.{env.EnvironmentName}.json", optional: true, reloadOnChange: true);
            config.AddEnvironmentVariables();
        })
        .ConfigureLogging((hostingContext, logging) =>
        {
            logging.AddConfiguration(hostingContext.Configuration.GetSection("Logging"));
            logging.AddNLog();
        })
        .UseStartup<Startup>()
        .Build();

    webHost.Run();
}

{
  "Logging": {
    "IncludeScopes": false,
    "Console": {
      "LogLevel": {
        "Default": "Debug",
        "System": "Information",
        "Microsoft": "Critical"
      }
    },
    "Debug": {
      "LogLevel": {
        "Default": "Debug",
        "System": "Information",
        "Microsoft": "Critical"
      }
    },
    "NLog": {
      "LogLevel": {
        "Default": "Debug",
        "System": "Information",
        "Microsoft": "Critical"
      }
    },
    "LogLevel": {
      "Default": "Debug",
      "System": "Information",
      "Microsoft": "Information"
    }
  }
}

It follows the same pattern as the built in Logger Providers such as DebugLoggerProvider

[304NotModified]

To be clear, the "old way" (https://github.com/NLog/NLog.Web/wiki/Missing-trace%5Cdebug-logs-in-ASP.NET-Core-2%3F) will still work, isn't?

[leewadhams]

@304NotModified yes that still works. The example you gave is just a generic filter across all LoggerProviders. All this attribute does is gives us a "friendly" name if we want to apply filters in config specifically for the NLog Logger Provider.

[304NotModified]

Thanks! Nice improvement!