Documentation

LiteralInterface extends TermInterface, TermCompareInterface
in

Description of RdfTerm

Tags
author

zozlak

Table of Contents

Constants

CAST_DATATYPE  = 2
CAST_LEXICAL_FORM  = 1

Methods

__toString()  : string
Should return:
equals()  : bool
getDatatype()  : string
Returns literal's datatype.
getLang()  : string|null
Returns literal's language tag.
getValue()  : mixed
withDatatype()  : LiteralInterface
Returns a new literal being a copy with this one with datatype set to a given value.
withLang()  : LiteralInterface
Returns a new literal being a copy of this one with a lang tag set to a given value.
withValue()  : LiteralInterface
Returns a new literal being a copy of this one with a given value.

Constants

Methods

__toString()

Should return:

public __toString() : string
  • an URI for named nodes and blank nodes
  • a value in lexical form for literals

For all other kind of terms the return value depends on the implementation

Return values
string

getDatatype()

Returns literal's datatype.

public getDatatype() : string

The method must return the actual datatype even if it's implicit. It means http://www.w3.org/1999/02/22-rdf-syntax-ns#langString must be returned for literals with a lang tag and http://www.w3.org/2001/XMLSchema#string must be returned for literals without lang tag and without datatype specified explicitely.

Return values
string

getLang()

Returns literal's language tag.

public getLang() : string|null

If a literal lacks a language tag, null should be returned. It means this method can't return an empty string.

Return values
string|null

withDatatype()

Returns a new literal being a copy with this one with datatype set to a given value.

public withDatatype(string $datatype) : LiteralInterface

Be aware it's impossibe to set the datatype to rdf::langString that way as it would require setting a non-empty lang tag. The withLang() method should be used in such a case as it changes the datatype implicitly.

As this method by definition doesn't allow to set a datatype allowing a literal to have a lang tag, it must set returned literal's lang tag to null.

This method must throw a \BadMethodCallException when called with a wrong datatype (http://www.w3.org/1999/02/22-rdf-syntax-ns#langString or an empty one).

Parameters
$datatype : string
Tags
see
withLang()
throws
BadMethodCallException
Return values
LiteralInterface

withLang()

Returns a new literal being a copy of this one with a lang tag set to a given value.

public withLang(string|null $lang) : LiteralInterface

Be aware setting a lang tag on a literal without one as well as dropping a lang tag from a literal having it implicitly changes literal's datatype. Setting a lang on a literal without one enforces setting its datatype to rdf:langString while dropping a lang from a literal having it changes literal's datatype to xsd:string (see https://www.w3.org/TR/rdf11-concepts/#section-Graph-Literal for details).

Parameters
$lang : string|null
Return values
LiteralInterface

withValue()

Returns a new literal being a copy of this one with a given value.

public withValue(int|float|string|bool|Stringable $value) : LiteralInterface

If the $value type is int/float/bool, the lang tag of the returned literal is set to null and the datatype is set to a corresponding XSD type (see the constructor documentation). If the $value is string/Stringable, the lang tag and datatype are preserved.

Parameters
$value : int|float|string|bool|Stringable
Return values
LiteralInterface 

        

        
    




    

    

                                

                

                            
    

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