MetaModel

This module contains the classes that are used to build the internal metamodel by introspecting the domain classes.

Many of the services defined (as interfaces) in the applib have implementations defined in this module (the rest are defined in Runtime Services).

What makes up the metamodel

The classes in this module are used to build up the metamodel from a variety of inputs sources:

metamodel inputs

@startuml
!include <logos/java>
!include <tupadr3/font-awesome/at>
!include <tupadr3/font-awesome/envira>
!include <office/Databases/database_cube>
!include <material/xml.puml>

legend top
|= notation |= explanation |
| ""__underline__"" | DDD Pattern|
endlegend

together {
    rectangle "<$database_cube><$at>\n<<Annotation>>\nORM (JPA)" as PERS
    rectangle "<$envira><$at>\n<<Annotation>>\nSpring" as SPRING
    rectangle "<img:https://causeway.apache.org/_/img/home/causeway-logo-65x48.png><$at>\n<<Annotation>>\nApache Causeway" as FW
    rectangle "<img:https://causeway.apache.org/_/img/home/causeway-logo-65x48.png><$java>\n<<Supporting Methods>>\nApache Causeway" as SM
    rectangle "<$java><$ma_xml><$at>\n<<Annotation>>\nJAXB" as JAXB

    SPRING -[hidden]- PERS
    PERS -[hidden]- FW
    FW -[hidden]- SM
    SM -[hidden]- JAXB

    note left of SPRING
        * __Repository__
        * Name (@Named)
        * Service (via FW @DomainService)
        * Component (via FW @DomainObject)
    end note

    note left of PERS
        * Cardinality
        * TableName
        * Column
        ** Name
        ** Length
        ** Type
    end note

    note left of FW
        * __Entitiy__
        ** Property
        ** Collection
        ** Action
        * __Factory__
        * Layout
        ** Property Sequence
            (Table and Forms)
        ** Action Sequence (Menu)
        ** Styles (cssClass)
        * ViewModel
        * Mixin
    end note

    note left of SM
        * autoComplete…()
        * choices…()
        * default…()
        * disable…()
        * get…()
        * hide…()
        * iconName()
        * set…()
        * title()
        * validate…()
    end note

    note left of JAXB
        * @XmlAccessorType
        * @XmlJavaTypeAdapter
        * @XmlRootElement
    end note
}

rectangle "<img:https://causeway.apache.org/_/img/home/causeway-logo-65x48.png>\nMetaModel" as MM

SPRING -> MM
PERS -> MM
FW -> MM
SM -> MM
JAXB -> MM

(MetaModelValidation) as MMV
MM <- MMV : perform \n consistency \n check

rectangle "WicketViewer" as UI
database DB
interface "Restful\nObjects" as REST
MM -d-> UI : generate
MM -d-> DB : generate
MM -d-> REST : generate

@enduml

Metamodel Concepts

The metamodel itself consists of the following parts:

Metamodel Terminology

@startuml

skinparam nodesep 20
skinparam ranksep 1

together {
	(Domain\nObject) as DO
	(Entity) as E
	(View\nModel) as VM
}
(<i>Apache Causeway</i>) as FW
(Persistence\nLayer) as PL
together {
	(Mixin) as M
	(Mixee) as ME
}
(Service) as S
(Domain\nService) as DS
(<i>Spring</i>) as SPRING
together {
	(Member) as MB
	(Property) as P
	(Collection) as C
	(Action) as A
}

DO <-d-"is a" VM
DO <-d-"is a" E
FW .u.> VM : manages
PL .u.> E : manages

P "is a"-u-> MB
C "is a"-u-> MB
A "is a"-u-> MB

DO --> MB : has 1..*

M "contributes\n a"..> MB
M "contributes\n to"-> ME
DO -> ME : can \n act \n as

SPRING ..> S : manages
DS "is a"-u-> S
DS --> A : has 1..*
@enduml

Thus:

Domain Objects have Properties, Collections
Viewmodels and Entities are specializations of Domain Objects.
- View Models are (lifecycle-) managed by Apache Causeway
- Entities are managed by the configured persistence mechanism.
Services in general are (lifecycle-) managed by Spring.

Some Services are also included in the metamodel; we call these Domain Services (annotated with @DomainService). Their Actions (like Domain Objects') will be visible either Menu Actions in the Wicket UI and/or through the REST API.
Mixins contribute either a Property, a Collection or an Action to their Mixee (-type).