Package com.yahoo.document.datatypes

Class ReferenceFieldValue

java.lang.Object

com.yahoo.vespa.objects.Selectable

com.yahoo.vespa.objects.Identifiable

com.yahoo.document.datatypes.FieldValue

com.yahoo.document.datatypes.ReferenceFieldValue

All Implemented Interfaces:

java.lang.Cloneable, java.lang.Comparable<FieldValue>

public class ReferenceFieldValue
extends FieldValue

A reference field value allows search queries to access fields in other document instances as if they were fields natively stored within the searched document. This allows modelling one-to-many relations such as a parent document with many children containing references back to the parent.

Each ReferenceFieldValue may contain a single document ID which specifies the instance the field should refer to. This document ID must have a type matching that of the reference data type of the field itself.

Note that references are not polymorphic. This means that if you have a document type "foo" inheriting "bar", you cannot have a reference<bar> field containing a document ID for a "foo" document.

Author:

vekterli

Field Summary

Fields

Modifier and Type	Field	Description
static int	classId

Constructor Summary

Constructors

Constructor	Description
ReferenceFieldValue(ReferenceDataType referenceType)	Creates an empty reference of the provided reference type.
ReferenceFieldValue(ReferenceDataType referenceType, DocumentId documentId)	Creates a reference pointing to a particular document instance in the document type referenced by referenceType.

Method Summary

Modifier and Type	Method	Description
void	assign(java.lang.Object o)	Assign this non-fieldvalue value to this field value.
void	clear()
static ReferenceFieldValue	createEmptyWithType(ReferenceDataType referenceType)
void	deserialize(Field field, FieldReader reader)	Read a field value from the specified reader
boolean	equals(java.lang.Object o)
DataType	getDataType()
java.util.Optional<DocumentId>	getDocumentId()
DocumentId	getWrappedValue()	Expose target document ID as this value's wrapped value.
int	hashCode()
void	printXml(XmlStream xml)
void	serialize(Field field, FieldWriter writer)	Write out field value to the specified writer
void	setDocumentId(DocumentId documentId)
java.lang.String	toString()

Methods inherited from class com.yahoo.document.datatypes.FieldValue

clone, compareTo, create, deserialize, getRecursiveValue, getRecursiveValue, onDeserialize, onSerialize, serialize, toXml

Methods inherited from class com.yahoo.vespa.objects.Identifiable

create, createFromId, deserialize, deserializeOptional, deserializeWithId, equals, getClassId, getUtf8, onGetClassId, putUtf8, registerClass, serialize, serializeOptional, serializeWithId, visitMembers

Methods inherited from class com.yahoo.vespa.objects.Selectable

select, select, selectMembers

Methods inherited from class java.lang.Object

finalize, getClass, notify, notifyAll, wait, wait, wait

Field Detail

classId

public static final int classId

Constructor Detail

ReferenceFieldValue

public ReferenceFieldValue(ReferenceDataType referenceType)

Creates an empty reference of the provided reference type.

Parameters:

referenceType - reference target type

ReferenceFieldValue

public ReferenceFieldValue(ReferenceDataType referenceType,
                           DocumentId documentId)

Creates a reference pointing to a particular document instance in the document type referenced by referenceType.

Parameters:

referenceType - reference target type

documentId - document ID of the same document type as that given by referenceType

Throws:

java.lang.IllegalArgumentException - if documentId is not of the expected document type

Method Detail

createEmptyWithType

public static ReferenceFieldValue createEmptyWithType(ReferenceDataType referenceType)

getDataType

public DataType getDataType()

Specified by:

getDataType in class FieldValue

getDocumentId

public java.util.Optional<DocumentId> getDocumentId()

setDocumentId

public void setDocumentId(DocumentId documentId)

printXml

public void printXml(XmlStream xml)

Specified by:

printXml in class FieldValue

clear

public void clear()

Specified by:

clear in class FieldValue

assign

public void assign(java.lang.Object o)

Description copied from class: FieldValue

Assign this non-fieldvalue value to this field value. This is used to be able to assign ints to Integer field values and List to Array field values and such.

Override to accept the specific types that should be legal.

Specified by:

assign in class FieldValue

equals

public boolean equals(java.lang.Object o)

Overrides:

equals in class com.yahoo.vespa.objects.Identifiable

hashCode

public int hashCode()

Overrides:

hashCode in class com.yahoo.vespa.objects.Identifiable

serialize

public void serialize(Field field,
                      FieldWriter writer)

Description copied from class: FieldValue

Write out field value to the specified writer

Specified by:

serialize in class FieldValue

deserialize

public void deserialize(Field field,
                        FieldReader reader)

Description copied from class: FieldValue

Read a field value from the specified reader

Specified by:

deserialize in class FieldValue

getWrappedValue

public DocumentId getWrappedValue()

Expose target document ID as this value's wrapped value. Primarily implemented to allow for transparent interoperability when used in concrete document types.

Overrides:

getWrappedValue in class FieldValue

Returns:

reference DocumentId, or null if none has been set

toString

public java.lang.String toString()

Overrides:

toString in class com.yahoo.vespa.objects.Identifiable