Event tracking for your aggregates to prepare your eventstore

BisAggregateRoot.cs

public abstract class BisAggregateRoot : AggregateRootMappedByConvention
    {
        private readonly List<object> _appliedEvents = new List<object>();

        protected readonly ICredentials Credentials = NcqrsEnvironment.Get<ICredentials>();

        protected BisAggregateRoot()
        {
        }

        protected BisAggregateRoot(Guid id) : base(id)
        {
        }
        //Tracking of changes can be removed here when the eventtracker can track the construction of the AR.
        public IEnumerable<object> GetChanges()
        {
            return _appliedEvents.ToArray();
        }

        protected override void OnEventApplied(Ncqrs.Eventing.UncommittedEvent appliedEvent)
        {
            _appliedEvents.Add(appliedEvent.Payload);

            base.OnEventApplied(appliedEvent);
        }
    }

BuilderExtensions.cs

    public static class BuilderExtensions
    {
        public static TAggregateRoot TrackChanges<TAggregateRoot>(this TAggregateRoot target) where TAggregateRoot : BisAggregateRoot
        {
            EventTracker.RegisterAggregate(target);
            return target;
        }

        public static IEnumerable<object> GetChanges(this BisAggregateRoot target)
        {
            return EventTracker.GetChanges(target);
        }

        public static ScientificStudy WithDefaultVisitDefined(this ScientificStudy target)
        {
            target.DefineVisit(Default.Id.For.Visit, "",Default.Subgroup.Men, "");
            return target;
        }

        //Other members left for convenience
    }

EventTracker.cs

    public static class EventTracker
    {
        private static readonly Dictionary<Guid, List<object>> Trackers = new Dictionary<Guid, List<object>>();

        public static void RegisterAggregate<TAggregateRoot>(TAggregateRoot aggregateRoot) where TAggregateRoot : BisAggregateRoot
        {
            var aggregateId = aggregateRoot.EventSourceId;
            if (Trackers.ContainsKey(aggregateId)) return;
            aggregateRoot.EventApplied += aggregateRoot_EventApplied;
            Trackers.Add(aggregateId, new List<object>());
        }

        public static IEnumerable<object> GetChanges<TAggregateRoot>(TAggregateRoot aggregateRoot) where TAggregateRoot : BisAggregateRoot
        {
            var aggregateId = aggregateRoot.EventSourceId;
            List<object> changes;
            if(Trackers.TryGetValue(aggregateId, out changes))
                return changes.AsReadOnly();
            
            return new List<object>();
        }

        private static void aggregateRoot_EventApplied(object sender, EventAppliedEventArgs e)
        {
            var aggregateId = ((BisAggregateRoot)sender).EventSourceId;
            List<object> changes;
            if (Trackers.TryGetValue(aggregateId, out changes))
            {
                var payload = e.Event.Payload;
                changes.Add(payload);
            }
        }
    }

gistfile1.txt

You can use the eventtracker like this.

New.ScientificStudy.TrackChanges().WithDefaultVisitDefined().WithDefaultSopAdded().WithDefaultSpecimenAdded().GetChanges();