1 files changed, 268 insertions, 0 deletions
diff --git a/www/wiki/extensions/SemanticMediaWiki/src/SPARQLStore/QueryEngine/DescriptionInterpreters/SomePropertyInterpreter.php b/www/wiki/extensions/SemanticMediaWiki/src/SPARQLStore/QueryEngine/DescriptionInterpreters/SomePropertyInterpreter.php
new file mode 100644
index 00000000..9350a7c1
--- /dev/null
+++ b/www/wiki/extensions/SemanticMediaWiki/src/SPARQLStore/QueryEngine/DescriptionInterpreters/SomePropertyInterpreter.php
@@ -0,0 +1,268 @@
+<?php
+
+namespace SMW\SPARQLStore\QueryEngine\DescriptionInterpreters;
+
+use SMW\DIProperty;
+use SMW\Query\Language\Description;
+use SMW\Query\Language\SomeProperty;
+use SMW\SPARQLStore\QueryEngine\Condition\FalseCondition;
+use SMW\SPARQLStore\QueryEngine\Condition\FilterCondition;
+use SMW\SPARQLStore\QueryEngine\Condition\SingletonCondition;
+use SMW\SPARQLStore\QueryEngine\Condition\WhereCondition;
+use SMW\SPARQLStore\QueryEngine\ConditionBuilder;
+use SMW\SPARQLStore\QueryEngine\DescriptionInterpreter;
+use SMWDataItem as DataItem;
+use SMWExpElement as ExpElement;
+use SMWExpNsResource as ExpNsResource;
+use SMWExporter as Exporter;
+use SMWTurtleSerializer as TurtleSerializer;
+
+/**
+ * @license GNU GPL v2+
+ * @since 2.1
+ *
+ * @author Markus Krötzsch
+ * @author mwjames
+ */
+class SomePropertyInterpreter implements DescriptionInterpreter {
+
+	/**
+	 * @var ConditionBuilder
+	 */
+	private $conditionBuilder;
+
+	/**
+	 * @var Exporter
+	 */
+	private $exporter;
+
+	/**
+	 * @since 2.1
+	 *
+	 * @param ConditionBuilder|null $conditionBuilder
+	 */
+	public function __construct( ConditionBuilder $conditionBuilder = null ) {
+		$this->conditionBuilder = $conditionBuilder;
+		$this->exporter = Exporter::getInstance();
+	}
+
+	/**
+	 * @since 2.2
+	 *
+	 * {@inheritDoc}
+	 */
+	public function canInterpretDescription( Description $description ) {
+		return $description instanceof SomeProperty;
+	}
+
+	/**
+	 * @since 2.2
+	 *
+	 * {@inheritDoc}
+	 */
+	public function interpretDescription( Description $description ) {
+
+		$joinVariable = $this->conditionBuilder->getJoinVariable();
+		$orderByProperty = $this->conditionBuilder->getOrderByProperty();
+
+		$property = $description->getProperty();
+
+		list( $innerOrderByProperty, $innerCondition, $innerJoinVariable ) = $this->doResolveInnerConditionRecursively(
+			$property,
+			$description->getDescription()
+		);
+
+		if ( $innerCondition instanceof FalseCondition ) {
+			return new FalseCondition();
+		}
+
+		$namespaces = $innerCondition->namespaces;
+
+		$objectName = $this->findObjectNameFromInnerCondition(
+			$innerCondition,
+			$innerJoinVariable,
+			$namespaces
+		);
+
+		list ( $subjectName, $objectName, $nonInverseProperty ) = $this->doExchangeForWhenInversePropertyIsUsed(
+			$property,
+			$objectName,
+			$joinVariable
+		);
+
+		$propertyName = $this->findMostSuitablePropertyRepresentation(
+			$property,
+			$nonInverseProperty,
+			$namespaces
+		);
+
+		$this->tryToAddPropertyPathForSaturatedHierarchy(
+			$innerCondition,
+			$nonInverseProperty,
+			$propertyName,
+			$description->getHierarchyDepth()
+		);
+
+		$condition = $this->concatenateToConditionString(
+			$subjectName,
+			$propertyName,
+			$objectName,
+			$innerCondition
+		);
+
+		$result = new WhereCondition( $condition, true, $namespaces );
+
+		// Record inner ordering variable if found
+		$result->orderVariables = $innerCondition->orderVariables;
+
+		if ( $innerOrderByProperty !== null && $innerCondition->orderByVariable !== '' ) {
+			$result->orderVariables[$property->getKey()] = $innerCondition->orderByVariable;
+		}
+
+		$this->conditionBuilder->addOrderByDataForProperty(
+			$result,
+			$joinVariable,
+			$orderByProperty,
+			DataItem::TYPE_WIKIPAGE
+		);
+
+		return $result;
+	}
+
+	private function doResolveInnerConditionRecursively( DIProperty $property, Description $description ) {
+
+		$innerOrderByProperty = null;
+
+		// Find out if we should order by the values of this property
+		if ( array_key_exists( $property->getKey(), $this->conditionBuilder->getSortKeys() ) ) {
+			$innerOrderByProperty = $property;
+		}
+
+		// Prepare inner condition
+		$innerJoinVariable = $this->conditionBuilder->getNextVariable();
+
+		$this->conditionBuilder->setJoinVariable( $innerJoinVariable );
+		$this->conditionBuilder->setOrderByProperty( $innerOrderByProperty );
+
+		$innerCondition = $this->conditionBuilder->mapDescriptionToCondition(
+			$description
+		);
+
+		return [ $innerOrderByProperty, $innerCondition, $innerJoinVariable ];
+	}
+
+	private function findObjectNameFromInnerCondition( $innerCondition, $innerJoinVariable, &$namespaces ) {
+
+		if ( !$innerCondition instanceof SingletonCondition ) {
+			return '?' . $innerJoinVariable;
+		}
+
+		$matchElement = $innerCondition->matchElement;
+
+		if ( $matchElement instanceof ExpElement ) {
+			$objectName = TurtleSerializer::getTurtleNameForExpElement( $matchElement );
+		} else {
+			$objectName = $matchElement;
+		}
+
+		if ( $matchElement instanceof ExpNsResource ) {
+			$namespaces[$matchElement->getNamespaceId()] = $matchElement->getNamespace();
+		}
+
+		return $objectName;
+	}
+
+	private function findMostSuitablePropertyRepresentation( DIProperty $property, DIProperty $nonInverseProperty, &$namespaces ) {
+
+		$redirectByVariable = $this->conditionBuilder->tryToFindRedirectVariableForDataItem(
+			$nonInverseProperty->getDiWikiPage()
+		);
+
+		// If the property is represented by a redirect then use the variable instead
+		if ( $redirectByVariable !== null ) {
+			return $redirectByVariable;
+		}
+
+		// Use helper properties in encoding values, refer to this helper property:
+		if ( $this->exporter->hasHelperExpElement( $property ) ) {
+			$propertyExpElement = $this->exporter->getResourceElementForProperty( $nonInverseProperty, true );
+		} elseif( !$property->isUserDefined() ) {
+			$propertyExpElement = $this->exporter->getSpecialPropertyResource(
+				$nonInverseProperty->getKey(),
+				SMW_NS_PROPERTY
+			);
+		} else {
+			$propertyExpElement = $this->exporter->getResourceElementForProperty( $nonInverseProperty );
+		}
+
+		if ( $propertyExpElement instanceof ExpNsResource ) {
+			$namespaces[$propertyExpElement->getNamespaceId()] = $propertyExpElement->getNamespace();
+		}
+
+		return TurtleSerializer::getTurtleNameForExpElement( $propertyExpElement );
+	}
+
+	private function doExchangeForWhenInversePropertyIsUsed( DIProperty $property, $objectName, $joinVariable ) {
+
+		$subjectName = '?' . $joinVariable;
+		$nonInverseProperty = $property;
+
+		// Exchange arguments when property is inverse
+		// don't check if this really makes sense
+		if ( $property->isInverse() ) {
+			$subjectName = $objectName;
+			$objectName = '?' . $joinVariable;
+			$nonInverseProperty = new DIProperty( $property->getKey(), false );
+		}
+
+		return [ $subjectName, $objectName, $nonInverseProperty ];
+	}
+
+	private function concatenateToConditionString( $subjectName, $propertyName, $objectName, $innerCondition ) {
+
+		$condition = "$subjectName $propertyName $objectName .\n";
+
+		$innerConditionString = $innerCondition->getCondition() . $innerCondition->getWeakConditionString();
+
+		if ( $innerConditionString === '' ) {
+			return $condition;
+		}
+
+		if ( $innerCondition instanceof FilterCondition ) {
+			return $condition . $innerConditionString;
+		}
+
+		return $condition . "{ $innerConditionString}\n";
+	}
+
+	/**
+	 * @note rdfs:subPropertyOf* where * means a property path of arbitrary length
+	 * can be found using the "zero or more" will resolve the complete path
+	 *
+	 * @see http://www.w3.org/TR/sparql11-query/#propertypath-arbitrary-length
+	 */
+	private function tryToAddPropertyPathForSaturatedHierarchy( &$condition, DIProperty $property, &$propertyName, $depth ) {
+
+		if ( !$this->conditionBuilder->isSetFlag( SMW_SPARQL_QF_SUBP ) || !$property->isUserDefined() || ( $depth !== null && $depth < 1 ) ) {
+			return null;
+		}
+
+		if ( $this->conditionBuilder->getHierarchyLookup() == null || !$this->conditionBuilder->getHierarchyLookup()->hasSubproperty( $property ) ) {
+			return null;
+		}
+
+		$subPropExpElement = $this->exporter->getSpecialPropertyResource( '_SUBP', SMW_NS_PROPERTY );
+
+		// A discret depth other than 0 or 1 is difficult to achieve
+		// @see https://stackoverflow.com/questions/18126949/limit-the-sparql-query-result-to-first-level-in-hierarchy
+		// Path operator is defined as:
+		// - elt* ZeroOrMorePath
+		// - elt? ZeroOrOnePath
+		$pathOp = $depth > 1 || $depth === null ? '*' : '?';
+
+		$propertyByVariable = '?' . $this->conditionBuilder->getNextVariable( 'sp' );
+		$condition->weakConditions[$propertyName] = "\n". "$propertyByVariable " . $subPropExpElement->getQName() . "$pathOp $propertyName .\n"."";
+		$propertyName = $propertyByVariable;
+	}
+
+}