1 files changed, 145 insertions, 0 deletions
diff --git a/www/wiki/extensions/SemanticMediaWiki/src/Exporter/Element/ExpLiteral.php b/www/wiki/extensions/SemanticMediaWiki/src/Exporter/Element/ExpLiteral.php
new file mode 100644
index 00000000..f800c482
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+++ b/www/wiki/extensions/SemanticMediaWiki/src/Exporter/Element/ExpLiteral.php
@@ -0,0 +1,145 @@
+<?php
+
+namespace SMW\Exporter\Element;
+
+use InvalidArgumentException;
+use RuntimeException;
+use SMWDataItem as DataItem;
+
+/**
+ * A single datatype literal for export. Defined by a literal value and a
+ * datatype URI.
+ *
+ * @license GNU GPL v2+
+ * @since 2.2
+ *
+ * @author Markus Krötzsch
+ * @author mwjames
+ */
+class ExpLiteral extends ExpElement {
+
+	/**
+	 * Lexical form of the literal.
+	 * @var string
+	 */
+	private $lexicalForm;
+
+	/**
+	 * Datatype URI for the literal.
+	 * @var string
+	 */
+	private $datatype;
+
+	/**
+	 * @var string
+	 */
+	private $lang = '';
+
+	/**
+	 * @note The given lexical form should be the plain string for
+	 * representing the literal without datatype or language information.
+	 * It must not use any escaping or abbreviation mechanisms.
+	 *
+	 * @param string $lexicalForm lexical form
+	 * @param string $datatype Data type URI or empty for untyped literals
+	 * @param string $lang
+	 * @param DataItem|null $dataItem
+	 *
+	 * @throws InvalidArgumentException
+	 */
+	public function __construct( $lexicalForm, $datatype = '', $lang = '', DataItem $dataItem = null ) {
+
+		if ( !is_string( $lexicalForm ) ) {
+			throw new InvalidArgumentException( '$lexicalForm needs to be a string' );
+		}
+
+		if ( !is_string( $datatype ) ) {
+			throw new InvalidArgumentException( '$datatype needs to be a string' );
+		}
+
+		if ( !is_string( $lang )  ) {
+			throw new InvalidArgumentException( '$lang needs to be a string and $datatype has to be of langString type' );
+		}
+
+		parent::__construct( $dataItem );
+
+		$this->lexicalForm = $lexicalForm;
+		$this->datatype = $datatype;
+
+		// 'http://www.w3.org/1999/02/22-rdf-syntax-ns#langString'
+		// can also be used instead of the simple Foo@lang-tag convention
+
+		// https://www.w3.org/TR/2004/REC-rdf-concepts-20040210/#dfn-language-identifier
+		// "...Plain literals have a lexical form and optionally a language tag as
+		// defined by [RFC-3066], normalized to lowercase..."
+		// https://www.w3.org/TR/rdf11-concepts/#section-Graph-Literal
+		// "...Lexical representations of language tags may be converted to
+		// lower case. The value space of language tags is always in lower case..."
+		$this->lang = strtolower( $lang );
+	}
+
+	/**
+	 * Returns a language tag with the language tag must be well-formed according
+	 * to BCP47
+	 *
+	 * @return string
+	 */
+	public function getLang() {
+		return $this->lang;
+	}
+
+	/**
+	 * Return the URI of the datatype used, or the empty string if untyped.
+	 *
+	 * @return string
+	 */
+	public function getDatatype() {
+		return $this->datatype;
+	}
+
+	/**
+	 * Return the lexical form of the literal. The result does not use
+	 * any escapings and might still need to be escaped in some contexts.
+	 * The lexical form is not validated or canonicalized.
+	 *
+	 * @return string
+	 */
+	public function getLexicalForm() {
+		return $this->lexicalForm;
+	}
+
+	/**
+	 * @since  2.2
+	 *
+	 * @return array
+	 */
+	public function getSerialization() {
+
+		$serialization = [
+			'type'     => self::TYPE_LITERAL,
+			'lexical'  => $this->lexicalForm,
+			'datatype' => $this->datatype,
+			'lang'     => $this->lang
+		];
+
+		return $serialization + parent::getSerialization();
+	}
+
+	/**
+	 * @see ExpElement::newFromSerialization
+	 */
+	protected static function deserialize( $serialization ) {
+
+		if ( !isset( $serialization['lexical'] ) || !isset( $serialization['datatype'] ) || !isset( $serialization['lang'] ) ) {
+			throw new RuntimeException( "Invalid format caused by a missing lexical/datatype element" );
+		}
+
+		return new self(
+			$serialization['lexical'],
+			$serialization['datatype'],
+			$serialization['lang'],
+			$serialization['dataitem']
+		);
+	}
+
+}