yreynhout

public class CurrentPortfolioProjection : 
  IHandle<AddedRealtyToPortfolio>, 
  IHandle<RemovedRealtyFromPortfolio> {

  Func<PortfolioContext> _contextFactory;

  public CurrentPortfolioProjection(Func<PortfolioContext> contextFactory) {
    _contextFactory = contextFactory;
  }

yreynhout

public class CurrentPortfolioProjection : 
  IHandle<AddedRealtyToPortfolio>, 
  IHandle<RemovedRealtyFromPortfolio> {

  IProjectionSqlOperations<CurrentPortfolioEntry> _operations;

  public CurrentPortfolioProjection(IProjectionSqlOperations<CurrentPortfolioEntry> operations) {
    _operations = operations;
  }

yreynhout

public class PushBasedProjectionSqlOperations<TProjection> :
  IProjectionSqlOperations<TProjection> {

  IObserver<ISqlStatement> _observer;
  ISqlStatementFactory _factory;

  public PushBasedProjectionSqlOperations(
    IObserver<ISqlStatement> observer,
    ISqlStatementFactory factory) {
    _observer = observer;

yreynhout

public class SqlStatementCollector : IObserver<ISqlStatement> {
  List<ISqlStatement> _statements;

  public SqlStatementCollector() {
    _statements = new List<ISqlStatement>();
  }

  public ISqlStatement[] CollectedStatements {
    get {
      return _statements.ToArray();

yreynhout

public class ThresholdedSqlStatementFlusher : IObserver<ISqlStatement> {
  readonly int _threshold;

  readonly ISqlConnectionTransactionFactory _connectionTransactionFactory;
  readonly ISqlBatchWriterFactory _batchWriterFactory;

  readonly List<ISqlStatement> _statements;

  public ThresholdedSqlStatementFlusher(
    int threshold, 

yreynhout

public class Video : VoodooMagic {
  public static Video New(VideoId id, Title title, Date releaseDate) {
    return new Video(
      Events.NewVideo(id, title, releaseDate));
  }

  Video(object initialEvent) {
    ApplyEvent(initialEvent);
  }

yreynhout

// In its simplest form
public class VideoTape {
  // as purely constructor injection of a "parent"
  public VideoTape(Video video) {
    _video = video;
  }
}

public class VideoTape : IVideoObjectInheritor {
  // as a hidden-from-the-public-eye method based injection

yreynhout

public class RenovationPolicy {
  public RenovationRequest FileRequestFor(Building building) {
    if(building.WasBetween(10.YearsAgo(), 25.YearsAgo()).WhenConstructed()) {
      //...
    }
  }
}

public class Building {
  internal BuildingAgeConstraint WasBetween(Date lower, Date upper) {

yreynhout

public interface IMessageBuilder {
  object Build();
}

public interface IEventBuilder : IMessageBuilder {
 IMessageBuilder IdentifiedBy(Guid id, int version);
}

public abstract class AggregateRootEntity {
  //...

yreynhout

using System;
using System.Collections.Generic;
using System.Reactive;
using System.Reactive.Subjects;

namespace NaiveEventSourcing {
  class Program {
    static void Main(string[] args) {
      var travelerRepository = new AlwaysNewTravelerRepository();
      var travelerService = new TravelerService(travelerRepository);