= Components

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This page provides user/config guides for each of the main components of the frameworks (viewer, persistence and security).

Also, the xref:core:_overview:about.adoc[System Overview] maps these components back to the corresponding Maven modules (and their respective dependencies).


== Security

The xref:security:ROOT:about.adoc[Security Guide] describes the security architecture and explains how to configure each of the various security components that integrate with Apache Causeway.


== Viewers

The framework provides three viewers that will automatically render the domain objects in your application into the presentation layer:

* xref:vw:ROOT:about.adoc[Web UI (Wicket)]
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Provides a human-usable UI, implemented using https://wicket.apache.org[Apache Wicket], and styled using Bootstrap.

* xref:gqlv:ROOT:about.adoc[GraphQL API]
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Presents your domain objects using link:https://graphql.org/[GraphQL], both queries and mutations.

* xref:vro:ROOT:about.adoc[REST API (Restful Objects)]
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Presents your domain objects in JSON representations, compliant either with link:http://restfulobjects.org[Restful Objects] specification or one of a number of other representations.



== Persistence

The framework allows xref:userguide:ROOT:domain-entities.adoc[domain entities] to be persisted using either:

* the xref:pjpa:ROOT:about.adoc[JPA/Eclipselink] object store
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for use with JPA and link:https://spring.io/projects/spring-data-jpa[Spring Data JPA].

* the xref:pjdo:ROOT:about.adoc[JDO/DataNucleus object store]
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for use with the JDO API.

Alternatively, you can "roll your own" (by implementing the xref:refguide:applib:index/ViewModel.adoc[ViewModel] interface) and persist with any data persistence technology that is supported by Spring Boot.



