Serilog's ILogger injected using Log.ForContext<T>, where T is the consumer

jameskind picture jameskind · Jun 3, 2016 · Viewed 8k times · Source

Serilog allows creating a context-aware logger:

Log.ForContext<T>()

I would like to register Serilog with SimpleInjector in such a way that T is the type of the consumer, i.e. it is which class it is injected in to.

e.g.

public class Car
{
    public Car(ILogger logger) <= would be injected using Log.ForContext<Car>()
    {             
    }
}

I can see this has been done with AutoFac.

And looking through the SimpleInjector documentation, there is a very promising overload of RegisterConditional() (with the Func<TypeFactoryContext, Type> parameter).

c.RegisterConditional(typeof (ILogger),
    x => Log.ForContext(x.Consumer.ImplementationType), <= won't compile as expecting a Type
    Lifestyle.Scoped,
    x => true);

however, I don't want to tell SimpleInjector which Type to build, but how to build one.

Answer

janhartmann picture janhartmann · Jun 4, 2016

I have integrated Serilog with Simple Injector with the following code based on @Steven genius answer on StackOverflow: logger wrapper best practice

public interface ILogger
{
    void Log(LogEntry entry);
}

public class SerilogLogger<T> : ILogger
{
    private readonly Serilog.ILogger _logger;

    public SerilogLogger()
    {
        _logger = new LoggerConfiguration()
            .WriteTo
            .Trace(LogEventLevel.Information)
            .CreateLogger()
            .ForContext(typeof (T));
    }

    public void Log(LogEntry entry)
    {
        /* Logging abstraction handling */
    }
}

public static class ContainerExtensions {

    public static void RegisterLogging(this Container container)
    {
        container.RegisterConditional(
            typeof(ILogger),
            c => typeof(SerilogLogger<>).MakeGenericType(c.Consumer.ImplementationType),
            Lifestyle.Singleton,
            c => true);
    }

}

In your Composition Root:

var container = new Container();
container.RegisterLogging();