DKNet.EfCore.Events 10.1.19

DKNet.EfCore.Events

Dispatches domain events raised by entities during EF Core SaveChanges. An entity queues a plain object from a business method (AddEvent(...)); this package publishes it after the save has actually committed — never before, never for a save that fails.

Features

• AddEvent(object) / AddEvent<TEvent>() on any IEventEntity (already implemented by Entity<TKey> / Entity in DKNet.EfCore.Abstractions) to queue events from domain methods.
• Automatic dispatch after a successful SaveChanges, via an EventHook that plugs into the same save pipeline as DKNet.EfCore.Hooks.
• [RaisesEvent] declared events — raise events by attribute instead of by hand, with no IEventEntity requirement (needs DKNet.EfCore.DtoGenerator for the payload).
• IEventPublisher / DefaultEventPublisher abstraction — plug in any messaging technology; multiple publishers can be registered and all run per save.
• EventException surfaces missing IMapper registrations and unresolved declared-event payloads instead of failing silently.

Install

dotnet add package DKNet.EfCore.Events

Quick start

public record OrderPlacedEvent(Guid OrderId, decimal Total);

public class Order : Entity<Guid>
{
    public Order(Guid id, decimal total) : base(id)
    {
        Total = total;
        AddEvent(new OrderPlacedEvent(id, total)); // queued, not dispatched yet
    }

    public decimal Total { get; private set; }
}

public sealed class LoggingEventPublisher(ILogger<LoggingEventPublisher> logger) : DefaultEventPublisher
{
    public override Task PublishAsync(object eventObj, CancellationToken cancellationToken = default)
    {
        logger.LogInformation("Publishing {EventType}", eventObj.GetType().Name);
        return Task.CompletedTask;
    }
}

// Startup — DbContext must be hook-aware for events to dispatch at all
services.AddDbContextWithHook<AppDbContext>((_, o) => o.UseSqlServer(connectionString));
services.AddEventPublisher<AppDbContext, LoggingEventPublisher>();

// Usage
db.Orders.Add(new Order(Guid.NewGuid(), 42.00m));
await db.SaveChangesAsync(); // OrderPlacedEvent reaches LoggingEventPublisher only after this commits

Customisation reference

There is no options class — every knob is a DI registration.

Behaviour that is deliberately not configurable: dispatch happens only after a successful save, a publisher that throws is logged and swallowed so the other publishers still run, and there is no retry, ordering knob, or dead-letter path.

Full documentation

Registration details, the complete dispatch lifecycle, [RaisesEvent] declared events, configuration, and how this composes with DKNet.EfCore.Abstractions and DKNet.EfCore.Hooks: https://github.com/baoduy/DKNet/blob/main/docs/EfCore/DKNet.EfCore.Events.md