[[partial]]
= Incomplete/partial support

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:page-partial:


These annotations have only incomplete/partial support, primarily relating to the management of value types.  We recommend that you do not use them for now.  Future versions of Apache Causeway may either formally deprecate/retire them, or we may go the other way and properly support them.  This will depend in part on the interactions between the Apache Causeway runtime, its two viewer implementations, and DataNucleus persistence.


.Annotations with incomplete/partial support
[cols="2,4a,1", options="header"]
|===
|Annotation
|Purpose
|Layer



|`@Value`
|Specify that a class has value-semantics. +

The `@Value` annotation indicates that a class should be treated as a value type rather than as a reference (or entity) type. It does this providing an implementation of a `o.a.c.applib.adapters.ValueSemanticsProvider`. +

For example: +

[source,java]
----
@Value(semanticsProviderClass=
    ComplexNumberValueSemanticsProvider.class)
public class ComplexNumber {
    ...
}
----

The `ValueSemanticsProvider` allows the framework to interact with the value, parsing strings and displaying as text, and encoding/decoding (for serialization).
|Domain

|===
