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== Wrapper Factory

If the xref:refguide:applib:index/services/wrapper/WrapperFactory.adoc[WrapperFactory] is used to call other objects then the metrics are captured for each sub-execution.





== Related Services


See also:

* the xref:refguide:applib:index/services/iactnlayer/InteractionContext.adoc[InteractionContext] is used to obtain the xref:refguide:applib:index/services/iactn/Interaction.adoc[Interaction] from which the member executions are published.

* the xref:refguide:applib:index/services/publishing/spi/EntityChangesSubscriber.adoc[EntityChangesSubscriber] is used to obtain the set of objects modified within the interaction

* the xref:refguide:applib:index/services/metrics/MetricsService.adoc[MetricsService] is used to obtain the objects that are loaded throughout the transaction; this info is used in order to instantiate the xref:refguide:applib:index/services/publishing/spi/EntityChanges.adoc[EntityChanges] object passed through to the xref:refguide:applib:index/services/publishing/spi/EntityChangesSubscriber.adoc[EntityChangesSubscriber].

* The services provided by this module combine very well with the xref:refguide:applib:index/services/publishing/spi/CommandSubscriber.adoc[CommandSubscriber] and with xref:refguide:applib:index/services/publishing/spi/EntityPropertyChangeSubscriber.adoc[EntityPropertyChangeSubscriber].
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The xref:refguide:applib:index/services/command/Command.adoc[Command]  captures the __cause__ of an interaction (an action was invoked, a property was edited), while the xref:refguide:applib:index/services/publishing/spi/ExecutionSubscriber.adoc[ExecutionSubscriber] captures the __effect__ of that interaction in terms of events, while the xref:refguide:applib:index/services/publishing/spi/EntityPropertyChangeSubscriber.adoc[EntityPropertyChangeSubscriber] captures the effect of the interaction in terms of changed state.

All of these services collaborate implicitly by way of the xref:refguide:applib:index/mixins/system/HasInteractionId.adoc[HasInteractionId] interface.

In contrast:

* The xref:refguide:applib:index/services/eventbus/EventBusService.adoc[EventBusService] differs from the xref:refguide:applib:index/services/publishing/spi/ExecutionSubscriber.adoc[ExecutionSubscriber] in that the former is intended for fine-grained publish/subscribe for object-to-object interactions _within_ an Apache Causeway domain object model.
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The event propagation is strictly in-memory, and there are no restrictions on the object acting as the event; it need not be serializable, for example.

