trait EventAdapter extends WriteEventAdapter with ReadEventAdapter

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):

  • 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
Source
EventAdapter.scala
Known Subclasses
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Inherited
  1. EventAdapter
  2. ReadEventAdapter
  3. WriteEventAdapter
  4. AnyRef
  5. Any
Implicitly
  1. by any2stringadd
  2. by StringFormat
  3. by Ensuring
  4. by ArrowAssoc
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Visibility
  1. Public
  2. Protected

Abstract Value Members

  1. abstract def fromJournal(event: Any, manifest: String): EventSeq

    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 org.apache.pekko.persistence.PersistentActor. Use the specialised org.apache.pekko.persistence.journal.EventSeq#single method to emit exactly one event, or org.apache.pekko.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

    event to be adapted before delivering to the PersistentActor

    manifest

    optionally provided manifest (type hint) in case the Adapter has stored one for this event, "" if none

    returns

    sequence containing the adapted events (possibly zero) which will be delivered to the PersistentActor

    Definition Classes
    ReadEventAdapter
  2. abstract def manifest(event: Any): String

    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.

    Definition Classes
    WriteEventAdapter
  3. abstract def toJournal(event: Any): Any

    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.

    event

    the application-side domain event to be adapted to the journal model

    returns

    the adapted event object, possibly the same object if no adaptation was performed

    Definition Classes
    WriteEventAdapter

Concrete Value Members

  1. final def !=(arg0: Any): Boolean
    Definition Classes
    AnyRef → Any
  2. final def ##: Int
    Definition Classes
    AnyRef → Any
  3. def +(other: String): String
    Implicit
    This member is added by an implicit conversion from EventAdapter toany2stringadd[EventAdapter] performed by method any2stringadd in scala.Predef.
    Definition Classes
    any2stringadd
  4. def ->[B](y: B): (EventAdapter, B)
    Implicit
    This member is added by an implicit conversion from EventAdapter toArrowAssoc[EventAdapter] performed by method ArrowAssoc in scala.Predef.
    Definition Classes
    ArrowAssoc
    Annotations
    @inline()
  5. final def ==(arg0: Any): Boolean
    Definition Classes
    AnyRef → Any
  6. final def asInstanceOf[T0]: T0
    Definition Classes
    Any
  7. def clone(): AnyRef
    Attributes
    protected[lang]
    Definition Classes
    AnyRef
    Annotations
    @throws(classOf[java.lang.CloneNotSupportedException]) @HotSpotIntrinsicCandidate() @native()
  8. def ensuring(cond: (EventAdapter) => Boolean, msg: => Any): EventAdapter
    Implicit
    This member is added by an implicit conversion from EventAdapter toEnsuring[EventAdapter] performed by method Ensuring in scala.Predef.
    Definition Classes
    Ensuring
  9. def ensuring(cond: (EventAdapter) => Boolean): EventAdapter
    Implicit
    This member is added by an implicit conversion from EventAdapter toEnsuring[EventAdapter] performed by method Ensuring in scala.Predef.
    Definition Classes
    Ensuring
  10. def ensuring(cond: Boolean, msg: => Any): EventAdapter
    Implicit
    This member is added by an implicit conversion from EventAdapter toEnsuring[EventAdapter] performed by method Ensuring in scala.Predef.
    Definition Classes
    Ensuring
  11. def ensuring(cond: Boolean): EventAdapter
    Implicit
    This member is added by an implicit conversion from EventAdapter toEnsuring[EventAdapter] performed by method Ensuring in scala.Predef.
    Definition Classes
    Ensuring
  12. final def eq(arg0: AnyRef): Boolean
    Definition Classes
    AnyRef
  13. def equals(arg0: AnyRef): Boolean
    Definition Classes
    AnyRef → Any
  14. final def getClass(): Class[_ <: AnyRef]
    Definition Classes
    AnyRef → Any
    Annotations
    @HotSpotIntrinsicCandidate() @native()
  15. def hashCode(): Int
    Definition Classes
    AnyRef → Any
    Annotations
    @HotSpotIntrinsicCandidate() @native()
  16. final def isInstanceOf[T0]: Boolean
    Definition Classes
    Any
  17. final def ne(arg0: AnyRef): Boolean
    Definition Classes
    AnyRef
  18. final def notify(): Unit
    Definition Classes
    AnyRef
    Annotations
    @HotSpotIntrinsicCandidate() @native()
  19. final def notifyAll(): Unit
    Definition Classes
    AnyRef
    Annotations
    @HotSpotIntrinsicCandidate() @native()
  20. final def synchronized[T0](arg0: => T0): T0
    Definition Classes
    AnyRef
  21. def toString(): String
    Definition Classes
    AnyRef → Any
  22. final def wait(arg0: Long, arg1: Int): Unit
    Definition Classes
    AnyRef
    Annotations
    @throws(classOf[java.lang.InterruptedException])
  23. final def wait(arg0: Long): Unit
    Definition Classes
    AnyRef
    Annotations
    @throws(classOf[java.lang.InterruptedException]) @native()
  24. final def wait(): Unit
    Definition Classes
    AnyRef
    Annotations
    @throws(classOf[java.lang.InterruptedException])

Deprecated Value Members

  1. def finalize(): Unit
    Attributes
    protected[lang]
    Definition Classes
    AnyRef
    Annotations
    @throws(classOf[java.lang.Throwable]) @Deprecated
    Deprecated

    (Since version 9)

  2. def formatted(fmtstr: String): String
    Implicit
    This member is added by an implicit conversion from EventAdapter toStringFormat[EventAdapter] performed by method StringFormat in scala.Predef.
    Definition Classes
    StringFormat
    Annotations
    @deprecated @inline()
    Deprecated

    (Since version 2.12.16) Use formatString.format(value) instead of value.formatted(formatString), or use the f"" string interpolator. In Java 15 and later, formatted resolves to the new method in String which has reversed parameters.

  3. def [B](y: B): (EventAdapter, B)
    Implicit
    This member is added by an implicit conversion from EventAdapter toArrowAssoc[EventAdapter] performed by method ArrowAssoc in scala.Predef.
    Definition Classes
    ArrowAssoc
    Annotations
    @deprecated
    Deprecated

    (Since version 2.13.0) Use -> instead. If you still wish to display it as one character, consider using a font with programming ligatures such as Fira Code.

Inherited from ReadEventAdapter

Inherited from WriteEventAdapter

Inherited from AnyRef

Inherited from Any

Inherited by implicit conversion any2stringadd fromEventAdapter to any2stringadd[EventAdapter]

Inherited by implicit conversion StringFormat fromEventAdapter to StringFormat[EventAdapter]

Inherited by implicit conversion Ensuring fromEventAdapter to Ensuring[EventAdapter]

Inherited by implicit conversion ArrowAssoc fromEventAdapter to ArrowAssoc[EventAdapter]

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