Pipelines with a shared logging mechanism

LoggingExample.cs

using System;

namespace StronglyTypedPipelines
{
    public interface ILoggingPipeline
    {
        void RaiseMessage(IPipelineStep sender, string message, object data);
    }

    public abstract class LoggingPipelineStep<INPUT, OUTPUT> : IPipelineStep<INPUT, OUTPUT>
    {
        public ILoggingPipeline ParentPipeline { get; set; }
        public abstract OUTPUT Process(INPUT input);
    }

    public class LoggingPipeline<INPUT, OUTPUT> : Pipeline<INPUT, OUTPUT>, ILoggingPipeline
    {
        public event Action<IPipelineStep, string, object> OnMessage;

        void ILoggingPipeline.RaiseMessage(IPipelineStep sender, String message, object data)
        {
            OnMessage?.Invoke(sender, message, data);
        }
    }

    public static class LoggingStepExtension
    {
        public static OUTPUT LogStep<INPUT, OUTPUT>(this INPUT input, ILoggingPipeline pipeline, LoggingPipelineStep<INPUT, OUTPUT> step)
        {
            step.ParentPipeline = pipeline;
            return step.Process(input);
        }
    }

    public class ExampleLoggingStep : LoggingPipelineStep<int, string>
    {
        public override String Process(int input)
        {
            ParentPipeline.RaiseMessage(this, "Calling the example step with input data", input);

            var output = input.ToString();

            ParentPipeline.RaiseMessage(this, "And the result is: ", output);

            return output;
        }
    }

    public class ExampleLoggingPipeline : LoggingPipeline<int,string>
    {
        public ExampleLoggingPipeline()
        {
            PipelineSteps = input => input
                .LogStep(this, new ExampleLoggingStep());
        }
    }

    public static class ExampleCode
    {
        public static void Run()
        {
            var pipeline = new ExampleLoggingPipeline();
            pipeline.OnMessage += (sender, msg, data) => Console.WriteLine(String.Format("[{0}] Received: {1} {2}", sender.GetType().Name, msg, data));

            var result = pipeline.Process(92);
        }
    }

}