Convert a event from its journal model to the applications domain model.
Convert a event from its journal model to the applications domain model.
One event may be adapter into multiple (or none) events which should be delivered to the akka.persistence.PersistentActor. Use the specialised akka.persistence.journal.EventSeq#single method to emit exactly one event, or akka.persistence.journal.EventSeq#empty in case the adapter is not handling this event. Multiple EventAdapter instances are applied in order as defined in configuration and their emitted event seqs are concatenated and delivered in order to the PersistentActor.
event to be adapted before delivering to the PersistentActor
optionally provided manifest (type hint) in case the Adapter has stored one for this event, ""
if none
sequence containing the adapted events (possibly zero) which will be delivered to the PersistentActor
Return the manifest (type hint) that will be provided in the fromJournal
method.
Return the manifest (type hint) that will be provided in the fromJournal
method.
Use ""
if manifest is not needed.
Convert domain event to journal event type.
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 com.example.myjournal.EventWithPrimaryKey(event, key)
.
The toJournal
adaptation must be an 1-to-1 transformation.
It is not allowed to drop incoming events during the toJournal
adaptation.
the application-side domain event to be adapted to the journal model
the adapted event object, possibly the same object if no adaptation was performed
An EventAdapter is both a WriteEventAdapter and a ReadEventAdapter. Facility to convert from and to specialised data models, as may be required by specialized persistence Journals.
Typical use cases include (but are not limited to):