RELEASE_NOTES.md

New in 0.24 (not released yet)

• Nothing yet

New in 0.23.1470 (released 2015-12-05)

• Breaking: EventFlow no longer ignores columns named Id in MSSQL read models. If you were dependent on this, use the MsSqlReadModelIgnoreColumn attribute
• Fixed: Instead of using MethodInfo.Invoke to call methods on reflected types, e.g. when a command is published, EventFlow now compiles an expression tree instead. This has a slight initial overhead, but provides a significant performance improvement for subsequent calls
• Fixed: Read model stores are only invoked if there's any read model updates
• Fixed: EventFlow now correctly throws an ArgumentException if EventFlow has been incorrectly configure with known versioned types, e.g. an event is emitted that hasn't been added during EventFlow initialization. EventFlow would handle the save operation correctly, but if EventFlow was reinitialized and the event was loaded before it being emitted again, an exception would be thrown as EventFlow would know which type to use. Please make sure to correctly load all event, command and job types before use
• Fixed: IReadModelFactory<>.CreateAsync(...) is now correctly used in read store mangers
• Fixed: Versioned type naming convention now allows numbers

New in 0.22.1393 (released 2015-11-19)

• New: To customize how a specific read model is initially created, implement a specific IReadModelFactory<> that can bootstrap that read model
• New: How EventFlow handles MSSQL read models has been refactored to allow significantly more freedom to developers. MSSQL read models are no longer required to implement IMssqlReadModel, only the empty IReadModel interface. Effectively, this means that no specific columns are required, meaning that the following columns are no longer enforced on MSSQL read models. Use the new required MsSqlReadModelIdentityColumn attribute to mark the identity column and the optional (but recommended) MsSqlReadModelVersionColumn to mark the version column.
  • string AggregateId
  • DateTimeOffset CreateTime
  • DateTimeOffset UpdatedTime
  • int LastAggregateSequenceNumber
• Obsolete: IMssqlReadModel and MssqlReadModel. Developers should instead use the MsSqlReadModelIdentityColumn and MsSqlReadModelVersionColumn attributes to mark the identity and version columns (read above). EventFlow will continue to support IMssqlReadModel, but it will be removed at some point in the future
• Fixed: Added missing UseElasticsearchReadModel<TReadModel, TReadModelLocator>() extension

New in 0.21.1312 (released 2015-10-26)

• New: Added Identity<>.NewComb() that creates sequential unique IDs which can be used to minimize database fragmentation
• New: Added IReadModelContext.Resolver to allow read models to fetch additional resources when events are applied
• New: The PrettyPrint() type extension method, mostly used for verbose logging, now prints even prettier type names, e.g. KeyValuePair<Boolean,Int64> instead of merely KeyValuePair'2, making log messages slightly more readable

New in 0.20.1274 (released 2015-10-22)

• Breaking: Entity<T> now inherits from ValueObject but uses only the Id field as equality component. Override GetEqualityComponents() if you have a different notion of equality for a specific entity
• Breaking: Entity<T> will now throw an ArgumentNullException if the id passed to its constructor is null
• Breaking: Fixed method spelling. Renamed ISpecification<T>.WhyIsNotStatisfiedBy to WhyIsNotSatisfiedBy and Specification<T>.IsNotStatisfiedBecause to IsNotSatisfiedBecause
• New: Read model support for Elasticsearch via the new NuGet package EventFlow.ReadStores.Elasticsearch

New in 0.19.1225 (released 2015-10-19)

• Breaking: AddDefaults now also adds the job type definition to the IJobsDefinitonService
• New: Implemented a basic specification pattern by providing ISpecification<T>, an easy-to-use Specificaion<T> and a set of extension methods. Look at the EventFlow specification tests to get started
• Fixed: IEventDefinitionService, ICommandDefinitonService and IJobsDefinitonService now longer throw an exception if an existing event is loaded, i.e., multiple calls to AddEvents(...), AddCommand(...) and AddJobs(...) no longer throws an exception
• Fixed: DomainError.With(...) no longer executes string.format if only one argument is parsed

New in 0.18.1181 (released 2015-10-07)

• POTENTIAL DATA LOSS for the files event store: The EventFlow internal functionality regarding event stores has been refactored resulting in information regarding aggregate names being removed from the event persistence layer. The files based event store no longer stores its events in the path [STORE PATH]\[AGGREGATE NAME]\[AGGREGATE ID]\[SEQUENCE].json, but in the path [STORE PATH]\[AGGREGATE ID]\[SEQUENCE].json. Thus if you are using the files event store for tests, you should move the events into the new file structure. Alternatively, implement the new IFilesEventLocator and provide your own custom event file layout.
• Breaking: Event stores have been split into two parts, the IEventStore and the new IEventPersistence. IEventStore has the same interface before but the implementation is now no longer responsible for persisting the events, only converting and serializing the persisted events. IEventPersistence handles the actual storing of events and thus if any custom event stores have been implemented, they should implement to the new IEventPersistence instead.
• New: Added IEntity, IEntity<> and an optional Entity<> that developers can use to implement DDD entities.

New in 0.17.1134 (released 2015-09-28)

• Fixed: Using NuGet package EventFlow.Autofac causes an exception with the message The type 'EventFlow.Configuration.Registrations.AutofacStartable' is not assignable to service 'Autofac.IStartable during EventFlow setup

New in 0.16.1120 (released 2015-09-27)

• Breaking: Removed HasRegistrationFor<> and GetRegisteredServices() from IServiceRegistration and added them to IResolver instead. The methods required that all service registrations went through EventFlow, which in most cases they will not
• Obsolete: Marked IServiceRegistration.RegisterIfNotRegistered(...), use the keepDefault = true on the other Register(...) methods instead
• New: Major changes have been done to how EventFlow handles service registration and bootstrapping in order for developers to skip calling CreateResolver() (or CreateContainer() if using the EventFlow.Autofac package) completely. EventFlow will register its bootstrap services in the IoC container and configure itself whenever the container is created
• New: Introduced IBootstrap interface that you can register. It has a single BootAsync(...) method that will be called as soon as the IoC container is ready (similar to that of IStartable of Autofac)
• Fixed: Correct order of service registration decorators. They are now applied in the same order they are applied, e.g., the last registered service decorator will be the "outer" service
• Fixed: Added missing ICommand<,> interface to abstract Command<,> class in EventFlow.Commands.

New in 0.15.1057 (released 2015-09-24)

• Fixed: Added UseHangfireJobScheduler() and marked UseHandfireJobScheduler() obsolete, fixing method spelling mistake

New in 0.14.1051 (released 2015-09-23)

• Breaking: All EventFlowOptions extensions are now IEventFlowOptions instead and EventFlowOptions implements this interface. If you have made your own extensions, you will need to use the newly created interface instead. Changed in order to make testing of extensions and classes dependent on the EventFlow options easier to test
• New: You can now bundle your configuration of EventFlow into modules that implement IModule and register these by calling EventFlowOptions.RegisterModule(...)
• New: EventFlow now supports scheduled job execution via e.g. Hangfire. You can create your own scheduler or install the new EventFlow.Hangfire NuGet package. Read the jobs documentation for more details
• New: Created the OWIN CommandPublishMiddleware middleware that can handle publishing of commands by posting a JSON serialized command to e.g. /commands/ping/1 in which ping is the command name and 1 its version. Remember to add authentication
• New: Created a new interface ICommand<TAggregate,TIdentity,TSourceIdentity> to allow developers to control the type of ICommand.SourceId. Using the ICommand<TAggregate,TIdentity> (or Command<TAggregate,TIdentity>) will still yield the same result as before, i.e., ICommand.SourceId being of type ISourceId
• New: The AddDefaults(...) now also adds the command type definition to the new ICommandDefinitonService

New in 0.13.962 (released 2015-09-13)

• Breaking: EventFlowOptions.AddDefaults(...) now also adds query handlers
• New: Added an optional Predicate<Type> to the following option extension methods that scan an Assembly: AddAggregateRoots(...), AddCommandHandlers(...), AddDefaults(...), AddEventUpgraders(...), AddEvents(...), AddMetadataProviders(...), AddQueryHandlers(...) and AddSubscribers(...)
• Fixed: EventFlowOptions.AddAggregateRoots(...) now prevents abstract classes from being registered when passing IEnumerable<Type>
• Fixed: Events published to RabbitMQ are now in the right order for chains of subscribers, if event A -> subscriber -> command -> aggregate -> event B, then the order of published events to RabbitMQ was event B and then event A

New in 0.12.891 (released 2015-09-04)

• Breaking: Aggregate root no longer have Aggregate removed from their when name, i.e., the metadata property with key aggregate_name (or MetadataKeys.AggregateName). If you are dependent on the previous naming, use the new AggregateName attribute and apply it to your aggregates
• Breaking: Moved Identity<> and IIdentity from the EventFlow.Aggregates namespace to EventFlow.Core as the identities are not specific for aggregates
• Breaking: ICommand.Id is renamed to ICommand.AggregateId to make "room" for the new ICommand.SourceId property. If commands are serialized, then it might be important verify that the serialization still works. EventFlow does not serialize commands, so no mitigation is provided. If the Command<,> is used, make sure to use the correct protected constructor
• Breaking: IEventStore.StoreAsync(...) now requires an additional ISourceId argument. To create a random one, use SourceId.New, but it should be e.g. the command ID that resulted in the events. Note, this method isn't typically used by developers
• New: Added ICommand.SourceId, which contains the ID of the source. The default (if your commands inherit from Command<,>) will be a new CommandId each time the a Command<,> instance is created. You can pass specific value, merely use the newly added constructor taking the ID. Alternatively you commands could inherit from the new DistinctCommand, enabling commands with the same state to have the same SourceId
• New: Duplicate commands can be detected using the new ISourceId. Read the EventFlow article regarding commands for more details
• New: Aggregate names can now be configured using the attribute AggregateName. The name can be accessed using the new IAggregateRoot.Name property
• New: Added Identity<>.NewDeterministic(Guid, string) enabling creation of deterministic GUIDs
• New: Added new metadata key source_id (MetadataKeys.SourceId) containing the source ID, typically the ID of the command from which the event originated
• New: Added new metadata key event_id (MetadataKeys.EventId) containing a deterministic ID for the event. Events with the same aggregate sequence number and from aggregates with the same identity, will have the same event identity
• Fixed: Identity<>.With(string) now throws an ArgumentException instead of a TargetInvocationException when passed an invalid identity
• Fixed: Aggregate roots now build the cache of Apply methods once, instead of when the method is requested the first time

New in 0.11.751 (released 2015-08-24)

• Breaking: EventFlowOptions.AddDefaults(...) now also adds event definitions
• New: RabbitMQ is now supported through the new NuGet package called EventFlow.RabbitMQ which enables domain events to be published to the bus
• New: If you want to subscribe to all domain events, you can implement and register a service that implements ISubscribeSynchronousToAll. Services that implement this will automatically be added using the AddSubscribers(...) or AddDefaults(...) extension to EventFlowOptions
• New: Use EventFlowOptions.UseAutofacAggregateRootFactory(...) to use an Autofac aggregate root factory, enabling you to use services in your aggregate root constructor
• New: Use EventFlowOptions.UseResolverAggregateRootFactory() to use the resolver to create aggregate roots. Same as UseAutofacAggregateRootFactory(...) but for when using the internal IoC container
• New: Use EventFlowOptions.AddAggregateRoots(...) to register aggregate root types
• New: Use IServiceRegistration.RegisterType(...) to register services by type

New in 0.10.642 (released 2015-08-17)

• Breaking: Updated NuGet reference Newtonsoft.Json to v7.0.1 (up from v6.0.8)
• Breaking: Remove the empty constructor from SingleValueObject<>
• New: Added SingleValueObjectConverter to help create clean JSON when e.g. domain events are serialized
• New: Added a protected method Register(IEventApplier) to AggregateRoot<,> that enables developers to override how events are applied. Use this to e.g. implement state objects
• New: Create AggregateState<,,> that developers can use to create aggregate state objects. Call Register(...) with the state object as argument to redirect events to it
• New: Allow AggregateRoot<,>.Apply(...), i.e., methods for applying events, to be private and protected
• New: Made AggregateRoot<,>.Emit(...) protected and virtual to allow overrides that e.g. add a standard set of metadata from the aggregate state.
• New: Made AggregateRoot<,>.ApplyEvent(...) protected and virtual to allow more custom implementations of applying events to the aggregate root.
• Fixed: Updated internal NuGet reference Dapper to v1.42 (up from v1.38)

New in 0.9.580 (released 2015-07-20)

• Braking: IEventStore.LoadAllEventsAsync and IEventStore.LoadAllEvents now take a GlobalPosition as an argument instead of a long for the starting position. The GlobalPosition is basically a wrapper around a string that hides the inner workings of each event store.
• New: NuGet package EventFlow.EventStores.EventStore that provides integration to Event Store. Its an initial version and shouldn't be used in production.

New in 0.8.560 (released 2015-05-29)

• Breaking: Remove all functionality related to global sequence numbers as it proved problematic to maintain. It also matches this quote:

  Order is only assured per a handler within an aggregate root boundary. There is no assurance of order between handlers or between aggregates. Trying to provide those things leads to the dark side.

  Greg Young

  • If you use a MSSQL read store, be sure to delete the LastGlobalSequenceNumber column during update, or set it to default NULL
  • IDomainEvent.GlobalSequenceNumber removed
  • IEventStore.LoadEventsAsync and IEventStore.LoadEvents taking a GlobalSequenceNumberRange removed

• Breaking: Remove the concept of event caches. If you really need this then implement it by registering a decorator for IEventStore

• Breaking: Moved IDomainEvent.BatchId to metadata and created MetadataKeys.BatchId to help access it

• New: IEventStore.DeleteAggregateAsync to delete an entire aggregate stream. Please consider carefully if you really want to use it. Storage might be cheaper than the historic knowledge within your events

• New: IReadModelPopulator is new and enables you to both purge and populate read models by going though the entire event store. Currently its only basic functionality, but more will be added

• New: IEventStore now has LoadAllEventsAsync and LoadAllEvents that enables you to load all events in the event store a few at a time.

• New: IMetadata.TimestampEpoch contains the Unix timestamp version of IMetadata.Timestamp. Also, an additional metadata key timestamp_epoch is added to events containing the same data. Note, the TimestampEpoch on IMetadata handles cases in which the timestamp_epoch is not present by using the existing timestamp

• Fixed: AggregateRoot<> now reads the aggregate version from domain events applied during aggregate load. This resolves an issue for when an IEventUpgrader removed events from the event stream

• Fixed: InMemoryReadModelStore<,> is now thread safe

New in 0.7.481 (released 2015-05-22)

• New: EventFlow now includes a IQueryProcessor that enables you to implement queries and query handlers in a structure manner. EventFlow ships with two ready-to-use queries and related handlers
  • ReadModelByIdQuery<TReadModel>: Supported by in-memory and MSSQL read model stores
  • InMemoryQuery<TReadModel>: Only supported by in-memory read model store, but lets you search for any read model based on a Predicate<TReadModel>

New in 0.6.456 (released 2015-05-18)

• Breaking: Read models have been significantly improved as they can now subscribe to events from multiple aggregates. Use a custom IReadModelLocator to define how read models are located. The supplied ILocateByAggregateId simply uses the aggregate ID. To subscribe to other events, simply implement IAmReadModelFor<,,> and make sure you have supplied a proper read model locator.
  • UseMssqlReadModel signature changed, change to .UseMssqlReadModel<MyReadModel, ILocateByAggregateId>() in order to have the previous functionality
  • UseInMemoryReadStoreFor signature changed, change to .UseInMemoryReadStoreFor<MyReadModel, ILocateByAggregateId>() in order to have the previous functionality
• Breaking: A warning is no longer logged if you forgot to subscribe to a aggregate event in your read model as read models are no longer strongly coupled to a specific aggregate and its events
• Breaking: ITransientFaultHandler now takes the strategy as a generic argument instead of the Use<> method. If you want to configure the retry strategy, use ConfigureRetryStrategy(...) instead
• New: You can now have multiple IReadStoreManager if you would like to implement your own read model handling
• New: IEventStore now has a LoadEventsAsync and LoadEvents that loads IDomainEvents based on global sequence number range
• New: Its now possible to register generic services without them being constructed generic types, i.e., register typeof(IMyService<>) as typeof(MyService<>)
• New: Table names for MSSQL read models can be assigned using the TableAttribute from System.ComponentModel.DataAnnotations
• Fixed: Subscribers are invoked after read stores have been updated, which ensures that subscribers can use any read models that were updated

New in 0.5.390 (released 2015-05-08)

• POTENTIAL DATA LOSS for files event store: Files event store now stores its log as JSON instead of an int in the form {"GlobalSequenceNumber":2}. So rename the current file and put in the global sequence number before startup
• Breaking: Major changes has been made regarding how the aggregate identity is implemented and referenced through interfaces. These changes makes it possible to access the identity type directly though all interface. Some notable examples are listed here. Note that this has NO impact on how data is stored!
  • IAggregateRoot changed to IAggregateRoot<TIdentity>
  • ICommand<TAggregate> changed to ICommand<TAggregate,TIdentity>
  • ICommandHandler<TAggregate,TCommand> changed to ICommandHandler<TAggregate,TIdentity, TCommand>
  • IAmReadModelFor<TEvent> changed to IAmReadModelFor<TAggregate,TIdentity,TEvent>
  • IDomainEvent<TEvent> changed to IDomainEvent<TAggregate,TIdentity>
• New: ICommandBus.Publish now takes a CancellationToken argument
• Fixed: MSSQL should list columns to SELECT when fetching events

New in 0.4.353 (released 2015-05-05)

• Breaking: ValueObject now uses public properties instead of both private and public fields
• Breaking: Aggregate IDs are no longer string but objects implementing IIdentity
• Breaking: MSSQL transient exceptions are now retried
• Breaking: All methods on IMsSqlConnection has an extra Label argument
• New: ITransientFaultHandler added along with default retry strategies for optimistic concurrency and MSSQL transient exceptions
• New: Release notes added to NuGet packages
• New: Better logging and more descriptive exceptions
• Fixed: Unchecked missing in ValueObject when claculating hash
• Fixed: NullReferenceException thrown if null was stored in SingleValueObject and ToString() was called

New in 0.3.292 (released 2015-04-30)

• First stable version of EventFlow