LiteralValue Class Reference

from PyKDE4.soprano import *

Namespace: Soprano

Detailed Description

\class LiteralValue literalvalue.h Soprano/LiteralValue

Represents a literal value of an RDF Node.

LiteralValue is based on QVariant to support a subset of the XML Schema types that are compatible with QT types.

The following types are supported natively including automatic type conversion. Other types are represented as strings.

int (Vocabulary.XMLSchema.xsdInt)

qlonglong (Vocabulary.XMLSchema.xsdLong)

unsigned int (Vocabulary.XMLSchema.unsignedInt)

qulonglong (Vocabulary.XMLSchema.unsignedLong)

bool (Vocabulary.XMLSchema.boolean)

double and float (Vocabulary.XMLSchema.xsdDouble) (float values are always converted to double)

QString (Vocabulary.XMLSchema.string or Vocabulary.RDF.XMLLiteral)

QDate (Vocabulary.XMLSchema.date)

QTime (Vocabulary.XMLSchema.time)

QDateTime (Vocabulary.XMLSchema.dateTime)

QByteArray (Vocabulary.XMLSchema.base64Binary)

Literal values can be converted from strings via fromString().

\sa Vocabulary.XMLSchema

Author:: Sebastian Trueg <trueg@kde.org>

Methods
	__init__ (self)
	__init__ (self, Soprano.LiteralValue other)
	__init__ (self, QVariant v)
	__init__ (self, long i)
	__init__ (self, float d)
	__init__ (self, QString string)
	__init__ (self, QLatin1String string)
	__init__ (self, QString string)
	__init__ (self, QDate date)
	__init__ (self, QTime time)
	__init__ (self, QDateTime datetime)
	__init__ (self, QByteArray data)
QUrl	dataTypeUri (self)
bool	isBool (self)
bool	isByteArray (self)
bool	isDate (self)
bool	isDateTime (self)
bool	isDouble (self)
bool	isInt (self)
bool	isInt64 (self)
bool	isPlain (self)
bool	isString (self)
bool	isTime (self)
bool	isUnsignedInt (self)
bool	isUnsignedInt64 (self)
bool	isValid (self)
Soprano.LanguageTag	language (self)
bool	operator != (self, Soprano.LiteralValue other)
bool	operator == (self, Soprano.LiteralValue other)
bool	toBool (self)
QByteArray	toByteArray (self)
QDate	toDate (self)
QDateTime	toDateTime (self)
float	toDouble (self)
int	toInt (self)
long	toInt64 (self)
QString	toString (self)
QTime	toTime (self)
long	toUnsignedInt (self)
long	toUnsignedInt64 (self)
QVariant::Type	type (self)
QVariant	variant (self)
Static Methods
Soprano.LiteralValue	createPlainLiteral (QString value, Soprano.LanguageTag lang=Soprano.LanguageTag())
QUrl	dataTypeUriFromType (QVariant::Type type)
Soprano.LiteralValue	fromString (QString value, QVariant::Type type)
Soprano.LiteralValue	fromString (QString value, QUrl dataTypeUri)
Soprano.LiteralValue	fromVariant (QVariant value, QUrl dataType)
QVariant::Type	typeFromDataTypeUri (QUrl dataTypeUri)

Method Documentation

__init__ ( self )

Create an empty literal value

__init__	(	self,
		Soprano.LiteralValue	other
	)

Default copy constructor

__init__	(	self,
		QVariant	v
	)

Creates a new LiteralValue from a QVariant. User types are not supported. If v contains an unsupported type an invalid LiteralValue is created.

\sa fromVariant()

__init__	(	self,
		long	i
	)

Creates a literal value of type unsigned long long (i.e. http://www.w3.org/2001/XMLSchema#unsignedLong)

__init__	(	self,
		float	d
	)

Creates a literal value of type double (i.e. http://www.w3.org/2001/XMLSchema#double)

__init__	(	self,
		QString	string
	)

Creates a literal value of type QString (i.e. http://www.w3.org/2001/XMLSchema#string)

__init__	(	self,
		QLatin1String	string
	)

Creates a literal value of type QString (i.e. http://www.w3.org/2001/XMLSchema#string)

__init__	(	self,
		QString	string
	)

Creates a literal value of type QString (i.e. http://www.w3.org/2001/XMLSchema#string)

__init__	(	self,
		QDate	date
	)

Creates a literal value of type QDate (i.e. http://www.w3.org/2001/XMLSchema#date)

__init__	(	self,
		QTime	time
	)

Creates a literal value of type QTime (i.e. http://www.w3.org/2001/XMLSchema#time)

__init__	(	self,
		QDateTime	datetime
	)

Creates a literal value of type QDateTime (i.e. http://www.w3.org/2001/XMLSchema#dateTime)

__init__	(	self,
		QByteArray	data
	)

Creates a literal value of type QByteArray (i.e. http://www.w3.org/2001/XMLSchema#base64Binary)

QUrl dataTypeUri ( self )

The XML Schema datatype URI.

Returns:: The URI of the XML Schema type referring to the stored type or an empty QUrl if the LiteralValue is empty or is a plain literal.

bool isBool ( self )

bool isByteArray ( self )

bool isDate ( self )

bool isDateTime ( self )

bool isDouble ( self )

bool isInt ( self )

bool isInt64 ( self )

bool isPlain ( self )

Determines if this literal value is a plain literal. Plain literals have no data type, but may have an optional language tag.

Returns:: true if this literal is plain

bool isString ( self )

Check if the literal contains a string value. Be aware that unknown literal types are also treated as strings. In that case compare dataTypeUrl.

bool isTime ( self )

bool isUnsignedInt ( self )

bool isUnsignedInt64 ( self )

bool isValid ( self )

Soprano.LanguageTag language ( self )

The language tag.

Returns:: The language tag of the plain literal or an empty LanguageTag if the LiteralValue has no language or it is a typed literal.

bool operator !=	(	self,
		Soprano.LiteralValue	other
	)

bool operator ==	(	self,
		Soprano.LiteralValue	other
	)

bool toBool ( self )

QByteArray toByteArray ( self )

QDate toDate ( self )

QDateTime toDateTime ( self )

float toDouble ( self )

int toInt ( self )

long toInt64 ( self )

QString toString ( self )

Each type can be converted to a string which means that toString in combination with dataTypeUrl provides all the information necessary to store this literal as RDF.

The string value is cached so calling it multiple times in a row is fast.

Warning:: For historical reasons this is not a user-readable representation.

\sa Node.toString

QTime toTime ( self )

long toUnsignedInt ( self )

long toUnsignedInt64 ( self )

QVariant::Type type ( self )

The type of the data.

Returns:: The QVariant type of the stored data or QVariant.Invalid if it is an empty value.

QVariant variant ( self )

The literal value represented in a QVariant. Be aware that the RDF typing information is lost in the converted variant.

Static Method Documentation

Soprano.LiteralValue createPlainLiteral	(	QString	value,
		Soprano.LanguageTag	lang=Soprano.LanguageTag()
	)

Create a plain LiteralValue object with an optional language tag.

Parameters:

value

The value of the literal.

Parameters:

lang

The language tag.

Both an empty value and lang will result in an invalid LiteralValue instance but an empty value with a valid lang is possible. A valid value with an empty lang will result in a plain, untyped literal with no language tag.

Returns:: A newly created LiteralValue instance based on the provided value and

lang.

QUrl dataTypeUriFromType	(	QVariant::Type	type
	)

Convert a QVariant.Type into an XML Schema URI.

Returns:: The XML Schema URI that corresponds to type or an empty QUrl if the type os unknown, i.e. can not be mapped to an XML Schema type.

Soprano.LiteralValue fromString	(	QString	value,
		QVariant::Type	type
	)

Create a LiteralValue object by parsing string value based on dataTypeUri.

Parameters:

value

The value of the literal. Might be converted based on dataTypeUri.

Parameters:

dataTypeUri

The data type URI. %Soprano can automatically convert all XML schema types. All other (unknown) types will be stored as a string value with the plain dataTypeUri as type. Thus, unknown literal types can still be used without automatic type conversion. (Be aware though, that changing the value of a LiteralValue instance will reset the type, ie. custom data type URIs will be lost.)

Both an empty value and dataTypeUri will result in an invalid LiteralValue instance but an empty value with a valid dataTypeUri is possible. A valid value with an invalid dataTypeUri will result in a LiteralValue of type Vocabulary.XMLSchema.string.

Returns:: A newly created LiteralValue instance based on the provided value and

dataTypeUri.

\sa fromString(const QString&, QVariant.Type), Vocabulary.XMLSchema

Soprano.LiteralValue fromString	(	QString	value,
		QUrl	dataTypeUri
	)

Create a LiteralValue object by parsing string value based on dataTypeUri.

Parameters:

value

The value of the literal. Might be converted based on dataTypeUri.

Parameters:

dataTypeUri

Returns:: A newly created LiteralValue instance based on the provided value and

dataTypeUri.

\sa fromString(const QString&, QVariant.Type), Vocabulary.XMLSchema

Soprano.LiteralValue fromVariant	(	QVariant	value,
		QUrl	dataType
	)

Create a LiteralValue object by converting value to the given dataType.

If the type of the variant matches the dataType this method has the same effect as the constructor which takes a QVariant as parameter. However, this method supports automatic conversion for a set of types including:

Conversion of different decimal types

Conversion of everything to xsd:string

Conversion of decimal types to xsd:dateTime (using QDateTime.fromTime_t())

Parameters:

value

The value the created LiteralValue should have. If invalid an invalid LiteralValue will be created.

Parameters:

dataType

The RDF literal data type the created LiteralValue should have. If empty the result will be the same as providing value to the constructor of LiteralValue. No conversion will take place.

Returns:: A newly created Literalvalue instance based on the given value and

dataType.

Since:: 2.7

QVariant::Type typeFromDataTypeUri	(	QUrl	dataTypeUri
	)

Convert an XML Schema URI into a QVariant.Type.

Returns:: The QVariant.Type corresponding to dataTypeUri or QVariant.Invalid if dataTypeUri is unknown.

LiteralValue Class Reference

Detailed Description

Methods

Static Methods

Method Documentation

Static Method Documentation

Modules