Typical use cases include (but are not limited to):
- adding metadata, a.k.a. "tagging" - by wrapping objects into tagged counterparts
- manually converting to the Journals storage format, such as JSON, BSON or any specialised binary format
- adapting incoming events in any way before persisting them by the journal
Thetype exposes the following members.
(Inherited from IReadEventAdapter.)
Convert an event from its journal model to the application's domain model.
One event may be adapter into multiple(or none) events which should be delivered to the PersistentActor. Use the specialised Single(Object) method to emit exactly one event, or Empty in case the adapter is not handling this event. Multiple instances are applied in order as defined in configuration and their emitted event seqs are concatenated and delivered in order to the PersistentActor.
Return the manifest (type hint) that will be provided in the FromJournal(Object, String) method. Use empty string if not needed.(Inherited from IWriteEventAdapter.)
(Inherited from IWriteEventAdapter.)
Convert domain event to journal event type.
Some journal may require a specific type to be returned to them, for example if a primary key has to be associated with each event then a journal may require adapters to return "EventWithPrimaryKey(event, key)".
The ToJournal(Object) adaptation must be an 1-to-1 transformation. It is not allowed to drop incoming events during the `toJournal` adaptation.