= ScalarMarshaller
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Provides an SPI to allow different scalar datatypes to be marshalled to and from GraphQL scalar types.

The implementations are called following a chain-of-responsibility pattern, first one matching is used. Use _javax.annotation.Priority_ (with _org.apache.causeway.applib.annotation.PriorityPrecedence_ values) to override the framework-provided defaults, earliest wins.

== API

[source,java]
.ScalarMarshaller.java
----
interface ScalarMarshaller<K> {
  boolean handles(Class<?> javaClass)     // <.>
  GraphQLScalarType getGqlScalarType()     // <.>
  K unmarshal(Object graphValue, Class<?> targetType)     // <.>
}
----

<.> xref:#handles_Class[handles(Class)]
+
--
Whether this marshaller is able to marshall/unmarshall the provided Java class.
--
<.> xref:#getGqlScalarType_[getGqlScalarType()]
+
--
The corresponding GraphQL scalar type for the Java-class.
--
<.> xref:#unmarshal_Object_Class[unmarshal(Object, Class)]
+
--
Unmarshal the provided graphQL value into its Java equivalent.
--

== Members

[#handles_Class]
=== handles(Class)

Whether this marshaller is able to marshall/unmarshall the provided Java class.

[#getGqlScalarType_]
=== getGqlScalarType()

The corresponding GraphQL scalar type for the Java-class.

[#unmarshal_Object_Class]
=== unmarshal(Object, Class)

Unmarshal the provided graphQL value into its Java equivalent.
