dasiths / neventlite Goto Github PK

Use streamEvents.IsEndOfStream() and streamEvents.NextEventNumber to implement recommended paging method.

var streamEvents = new List<ResolvedEvent>();
StreamEventsSlice currentSlice;
var nextSliceStart = StreamPosition.Start;
do
{
    currentSlice = 
    _eventStoreConnection.ReadStreamEventsForward("myStream", nextSliceStart,
                                                  200, false)
                                                  .Result;

    nextSliceStart = currentSlice.NextEventNumber;

    streamEvents.AddRange(currentSlice.Events);
} while (!currentSlice.IsEndOfStream);

Hi @dasiths, thank you for your work.

Just a question,
in /src/NEventLite/Repository/Repository.cs (the CreateNewInstance() method), is it necessary to force a public parameter-less constructor to be defined on the aggregate class?
Why not something like this?
return (TAggregate)Activator.CreateInstance(typeof(TAggregate), nonPublic: true);

Thank you in advance. I am new to Github so I am sorry if I am not doing this right.

EventStoreSnapshotStorageProvider.GetSnapshot(AggregateID,Version) must query Aggregate version or find the closest before.

At the moment it queries for the snapshot version.

Why use a lock in the writing method or the repository? This will harm performance AFAIK
https://github.com/dasiths/EventSourcingDemo/blob/master/EventSourcingDemo/Repository/Repository.cs

There are a few other .net packages that implemented Event Store. It will be useful in readme.md to see what are advantages( and disadvantages) of this library compare to other packages, such as EventStore .net Client API https://github.com/EventStore/EventStore and
https://github.com/SQLStreamStore/SQLStreamStore.

The author of SQLStreamStore answered to similar question at
SQLStreamStore/SQLStreamStore#108 (comment)

Add some test cases to aggregate event handling and repository

I'm planning to create v2 of NEventLite soon and there will be some breaking changes. It's not formalized yet but I plan to do the following.

• Move Commands, CommandHandler and ExternalEventHandlers out of the core project as they aren't a critical part of the workflow.
• Add support for custom Id data type like (Guid, Int or String) for Aggregates and Events.
• Add support for async (internal) event handlers.

My goal for NEventLite is not to be a full framework that solves every problem but rather solves one particular problem well. It will act as a library that allows you to manage the lifecycle of your aggregates in an event sourced system. You can use the plethora of other (OSS and paid) Command dispatching libraries to create a command pipeline and do the same when you need to dispatch events over the cloud. NEventLite will plugin and work with any of these solutions.

The old version can be found here https://github.com/dasiths/NEventLite_legacy

I have run into an issue where the FindEventHandlerMethodsInAggregate method in ReflectionHelper fails intermittently. I have not been able to chase it down exactly but it seems it could be a threading issue. If I avoid throwing the exception if the dictionary for the Aggregate has already been added (see below), it seems to fix the issue. Thoughts?

if (AggregateEventHandlerCache.TryAdd(aggregateType, eventHandlers) == false 
    && AggregateEventHandlerCache.ContainsKey(aggregateType) == false)
{
    throw new System.Exception($"Error registering methods for handling events in {aggregateType.Name}");
}

This will help make project work with .NET Core as .NET standard has to call GetTypeInfo()
http://stackoverflow.com/questions/36118978/using-reflection-in-net-core