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WARNING: TODO: was renamed/moved from auditing+publishing to entityChangePublishing

The `entityChangePublishing` element for a domain object means that all registered implementation(s) of the link:https://isis.apache.org/refguide/2.0.0-M3/applib-svc/PublisherService.html#spi[`PublisherService` SPI] will be notified of the identity and nature of the change (created/updated/deleted) to the domain object.

:examples/demo/domain/src/main/java/demoapp/dom/annotDomain/DomainObject/publishing/DomainObjectPublishingVm-description.adoc
This is done _after_ the interaction in which the object(s) was changed has completed.

This notification is done only once per interaction, so will include _all_ domain objects that were changed.
The event object can be converted to type xref:https://isis.apache.org/refguide/2.0.0-M3/schema/chg.html[ChangesDto].

Common use cases are to replicate data to another system, or for gathering metrics ("which objects change the most?").
A typical SPI implementation could publish the event over the network, or perhaps store in a database.
(Note that the framework provides an link:https://isis.apache.org/mappings/2.0.0-M3/outbox-publisher/about.html[out-of-the-box implementation] of the link:https://microservices.io/patterns/data/transactional-outbox.html[outbox pattern]).

The element can be specified using either the `@DomainObject` annotation, or through a meta-annotation.

NOTE: Publishing of domain objects is only supported for domain entities, not view models.


== Explanation of the Demo

The demo provides a view model which can be used to create, update or delete four variations of a domain entity:

* annotated using `@DomainObject(entityChangePublishing=...)` for both enabled and disabled
* meta-annotated as enabled
* meta-annotated as disabled, but then overridden

These can be updated using the view model's `create`, `update all` and `delete` actions, generating publishing events.

TIP: Click through to the entity objects to see examples of the annotations applied.


//
// to fix up
//
//== ExecutionSubscriber
//
//The demo also has a simple implementation of `ExecutionSubscriber` that just stores the DTOs in memory:
//
//[source,java]
//----
//include::spiimpl/PublisherServiceSpiForDomainObject.java[tags=class]
//----
//<.> serializes to `ChangesDto`, as defined by the link:https://isis.apache.org/refguide/2.0.0-M3/schema/chg.html[Apache Isis schema].
//
//The demo implementation also provides a way to query these executions:
//
//[source,java,indent=0]
//----
//include::spiimpl/PublisherServiceSpiForDomainObject.java[tags=demo]
//----
//
//Supporting mixins surface this list as contributions on the object:
//
//* `publishedObjects` collection:
//+
//[source,java,indent=0]
//----
//include::spiimpl/DomainObjectPublishingVm_publishedObjects.java[tags=class]
//----
//
//* `clearPublishedObjects` action:
//+
//[source,java,indent=0]
//----
//include::spiimpl/DomainObjectPublishingVm_clearPublishedObjects.java[tags=class]
//----
//
//
//For the three (of the four in total) domain entities where publishing is enabled, this collection should be appended to when the `create`, `update all` or `delete` actions are invoked.
//
//[NOTE]
//====
//Because the `Publisher` is notified after the interaction has completed, it's necessary to refresh the page to see the collection of changes being updated.
//
//This can be done simply by clicking on the view model's title.
//====


== Configuration

By default, publishing of domain objects is disabled.
This can be configured globally:

[source,yaml]
.application.yml
----
isis:
  applib:
    annotation:
      domain-object:
        entityChangePublishing: none
----

