Writer interface for RDF output. More...

Inheritance diagram for Wikimedia\Purtle\RdfWriter:

Public Member Functions
	blank ( $label=null)
	Returns the local name of a blank node, for use with the "_" prefix.

	start ()
	Start the document.

	finish ()
	Finish the document.

	drain ()
	Generates an RDF string from the current buffers state and returns it.

	prefix ( $prefix, $iri)
	Declare a prefix for later use.

	about ( $base, $local=null)
	Start an "about" (subject) clause, given a subject.

	say ( $base, $local=null)
	Start a predicate clause.

	is ( $base, $local=null)
	Produce a resource as the object of a statement.

	text ( $text, $language=null)
	Produce a text literal as the object of a statement.

	value ( $value, $typeBase=null, $typeLocal=null)
	Produce a typed or untyped literal as the object of a statement.

	a ( $typeBase, $typeLocal=null)
	Shorthand for say( 'a' )->is( $type ).

	sub ()
	Returns a document-level sub-writer.

	getMimeType ()
	Returns the MIME type of the RDF serialization the writer produces.

Detailed Description

Writer interface for RDF output.

RdfWriter instances are generally stateful, but should be implemented to operate in a stream-like manner with a minimum of state.

This is intended to provide a "fluent interface" that allows programmers to use a turtle-like structure when generating RDF output. E.g.:

$writer->prefix( 'acme', 'http://acme.test/terms/' );
$writer->about( 'http://quux.test/Something' )
  ->say( 'acme', 'name' )->text( 'Thingy' )->text( 'Dingsda', 'de' )
  ->say( 'acme', 'owner' )->is( 'http://quux.test/' );

To get the generated RDF output, use the drain() method.

Note: : The contract of this interface follows the GIGO principle, that is, implementations are not required to ensure valid output or prompt failure on invalid input. Speed should generally be favored over safety.

Caveats:

no relative iris
predicates must be qnames
no inline/nested blank nodes
no comments
no collections
no automatic conversion of iris to qnames

@license GPL-2.0-or-later

Author: Daniel Kinzler

Member Function Documentation

◆ a()

Wikimedia\Purtle\RdfWriter::a	(		$typeBase,
			$typeLocal = null )

Shorthand for say( 'a' )->is( $type ).

Parameters

string	$typeBase	The data type's QName prefix if $typeLocal is given, or an IRI or shorthand if $typeLocal is null.
string \| null	$typeLocal	The data type's QName suffix, or null if $typeBase is an IRI or shorthand.

Returns: RdfWriter $this

Implemented in Wikimedia\Purtle\RdfWriterBase.

◆ about()

Wikimedia\Purtle\RdfWriter::about	(		$base,
			$local = null )

Start an "about" (subject) clause, given a subject.

Can occur at the beginning odf the output sequence, but can later only follow a call to is(), text(), or value(). Should fail if called at an inappropriate time in the output sequence.

Parameters

string	$base	A QName prefix if $local is given, or an IRI if $local is null.
string \| null	$local	A QName suffix, or null if $base is an IRI.

Returns: RdfWriter $this

Implemented in Wikimedia\Purtle\RdfWriterBase.

◆ blank()

Wikimedia\Purtle\RdfWriter::blank ( $label = null )

Returns the local name of a blank node, for use with the "_" prefix.

Parameters

string | null $label node label, will be generated if not given.

Returns: string A local name for the blank node, for use with the '_' prefix.

Implemented in Wikimedia\Purtle\RdfWriterBase.

◆ drain()

Wikimedia\Purtle\RdfWriter::drain ( )

Generates an RDF string from the current buffers state and returns it.

The buffer is reset to the empty state. Before the result string is generated, implementations should close any pending syntactical structures (close tags, generate footers, etc).

Returns: string The RDF output

Implemented in Wikimedia\Purtle\RdfWriterBase.

◆ finish()

Wikimedia\Purtle\RdfWriter::finish ( )

Finish the document.

May generate a footer.

This will detach all sub-writers that had earlier been returned by sub().

Implemented in Wikimedia\Purtle\RdfWriterBase.

◆ getMimeType()

Wikimedia\Purtle\RdfWriter::getMimeType ( )

Returns the MIME type of the RDF serialization the writer produces.

Returns: string a MIME type

Implemented in Wikimedia\Purtle\JsonLdRdfWriter, Wikimedia\Purtle\NTriplesRdfWriter, Wikimedia\Purtle\TurtleRdfWriter, and Wikimedia\Purtle\XmlRdfWriter.

◆ is()

Wikimedia\Purtle\RdfWriter::is	(		$base,
			$local = null )

Produce a resource as the object of a statement.

Can only follow a call to say() or a call to one of is(), text(), or value(). Should fail if called at an inappropriate time in the output sequence.

Parameters

string	$base	A QName prefix if $local is given, or an IRI or shorthand if $local is null.
string \| null	$local	A QName suffix, or null if $base is an IRI or shorthand.

Returns: RdfWriter $this

Implemented in Wikimedia\Purtle\RdfWriterBase.

◆ prefix()

Wikimedia\Purtle\RdfWriter::prefix	(		$prefix,
			$iri )

Declare a prefix for later use.

Prefixes should be declared before being used. Should not be called after start().

Parameters

string	$prefix
string	$iri	a IRI

Implemented in Wikimedia\Purtle\RdfWriterBase.

◆ say()

Wikimedia\Purtle\RdfWriter::say	(		$base,
			$local = null )

Start a predicate clause.

Can only follow a call to about() or say(). Should fail if called at an inappropriate time in the output sequence.

Note: Unlike about() and is(), say() cannot be called with a full IRI, but must always use qname form. This is required to cater to output formats that do not allow IRIs to be used as predicates directly, like RDF/XML.

Parameters

string	$base	A QName prefix if $local is given, or a shorthand. MUST NOT be an IRI.
string \| null	$local	A QName suffix, or null if $base is a shorthand.

Returns: RdfWriter $this

Implemented in Wikimedia\Purtle\RdfWriterBase.

◆ start()

Wikimedia\Purtle\RdfWriter::start ( )

Start the document.

May generate a header.

Implemented in Wikimedia\Purtle\RdfWriterBase.

◆ sub()

Wikimedia\Purtle\RdfWriter::sub ( )

Returns a document-level sub-writer.

This can be used to generate parts statements out of sequence. Output generated by the sub-writer will be present in the return value of drain(), after any output generated by this writer itself.

Note: calling drain() on sub-writers results in undefined behavior!; using sub-writers after finish() has been called on this writer results in undefined behavior!

Returns: RdfWriter

Implemented in Wikimedia\Purtle\RdfWriterBase.

◆ text()

Wikimedia\Purtle\RdfWriter::text	(		$text,
			$language = null )

Produce a text literal as the object of a statement.

Can only follow a call to say() or a call to one of is(), text(), or value(). Should fail if called at an inappropriate time in the output sequence.

Parameters

string	$text	the text to be placed in the output
string \| null	$language	the language the text is in

Returns: RdfWriter $this

Implemented in Wikimedia\Purtle\RdfWriterBase.

◆ value()

Wikimedia\Purtle\RdfWriter::value	(	$value,
		$typeBase = null,
		$typeLocal = null )

Produce a typed or untyped literal as the object of a statement.

Can only follow a call to say() or a call to one of is(), text(), or value(). Should fail if called at an inappropriate time in the output sequence.

Parameters

string	$value	the value encoded as a string
string \| null	$typeBase	The data type's QName prefix if $typeLocal is given, or an IRI or shorthand if $typeLocal is null.
string \| null	$typeLocal	The data type's QName suffix, or null if $typeBase is an IRI or shorthand.

Returns: RdfWriter $this

Implemented in Wikimedia\Purtle\RdfWriterBase.

The documentation for this interface was generated from the following file:

src/RdfWriter.php

Public Member Functions

Detailed Description

Member Function Documentation

◆ a()

◆ about()

◆ blank()

◆ drain()

◆ finish()

◆ getMimeType()

◆ is()

◆ prefix()

◆ say()

◆ start()

◆ sub()

◆ text()

◆ value()