1 files changed, 252 insertions, 0 deletions
diff --git a/www/wiki/extensions/SemanticMediaWiki/src/SQLStore/QueryEngine/OrderCondition.php b/www/wiki/extensions/SemanticMediaWiki/src/SQLStore/QueryEngine/OrderCondition.php
new file mode 100644
index 00000000..10e974a6
--- /dev/null
+++ b/www/wiki/extensions/SemanticMediaWiki/src/SQLStore/QueryEngine/OrderCondition.php
@@ -0,0 +1,252 @@
+<?php
+
+namespace SMW\SQLStore\QueryEngine;
+
+use RuntimeException;
+use SMW\DataValueFactory;
+use SMW\DataValues\PropertyChainValue;
+use SMW\Query\DescriptionFactory;
+use SMW\Query\Language\Description;
+
+/**
+ * Modifies a given query object at $qid to account for all ordering conditions
+ * in the Query $query. It is always required that $qid is the id of a query
+ * that joins with the SMW ID_TABELE so that the field alias.smw_title is
+ * available for default sorting.
+ *
+ * @license GNU GPL v2+
+ * @since 2.5
+ *
+ * @author mwjames
+ * @author Markus Krötzsch
+ */
+class OrderCondition {
+
+	/**
+	 * @var QuerySegmentListBuilder
+	 */
+	private $querySegmentListBuilder;
+
+	/**
+	 * @var DescriptionFactory
+	 */
+	private $descriptionFactory;
+
+	/**
+	 * Array of sorting requests ("Property_name" => "ASC"/"DESC"). Used during query
+	 * processing (where these property names are searched while compiling the query
+	 * conditions).
+	 *
+	 * @var string[]
+	 */
+	private $sortKeys = [];
+
+	/**
+	 * @var boolean
+	 */
+	private $isSupported = true;
+
+	/**
+	 * @var boolean
+	 */
+	private $asUnconditional = false;
+
+	/**
+	 * @since 2.5
+	 *
+	 * @param QuerySegmentListBuilder $querySegmentListBuilder
+	 */
+	public function __construct( QuerySegmentListBuilder $querySegmentListBuilder ) {
+		$this->querySegmentListBuilder = $querySegmentListBuilder;
+		$this->descriptionFactory = new DescriptionFactory();
+	}
+
+	/**
+	 * @since 2.5
+	 *
+	 * @param array $sortKeys
+	 */
+	public function setSortKeys( $sortKeys ) {
+		$this->sortKeys = $sortKeys;
+	}
+
+	/**
+	 * @since 2.5
+	 *
+	 * @return string[]
+	 */
+	public function getSortKeys() {
+		return $this->sortKeys;
+	}
+
+	/**
+	 * @since 2.5
+	 *
+	 * @return array
+	 */
+	public function getErrors() {
+		return $this->querySegmentListBuilder->getErrors();
+	}
+
+	/**
+	 * @since 2.5
+	 *
+	 * @param boolean $isSupported
+	 */
+	public function isSupported( $isSupported ) {
+		$this->isSupported = $isSupported;
+	}
+
+	/**
+	 * @since 3.0
+	 *
+	 * @param boolean $asUnconditional
+	 */
+	public function asUnconditional( $asUnconditional ) {
+		$this->asUnconditional = $asUnconditional;
+	}
+
+	/**
+	 * @since 2.5
+	 *
+	 * @param integer $qid
+	 *
+	 * @return QuerySegment[]
+	 */
+	public function apply( $qid ) {
+
+		if ( !$this->isSupported ) {
+			return $this->querySegmentListBuilder->getQuerySegmentList();
+		}
+
+		$querySegment = $this->querySegmentListBuilder->findQuerySegment(
+			$qid
+		);
+
+		$extraDescriptions = $this->collectExtraDescriptionsFromSortKeys(
+			$querySegment
+		);
+
+		if ( $extraDescriptions !== [] ) {
+			$this->addConjunctionFromExtraDescriptions( $querySegment, $extraDescriptions );
+		}
+
+		return $this->querySegmentListBuilder->getQuerySegmentList();
+	}
+
+	private function collectExtraDescriptionsFromSortKeys( $querySegment ) {
+
+		$extraDescriptions = [];
+
+		foreach ( $this->sortKeys as $label => $order ) {
+
+			if ( !is_string( $label ) ) {
+				throw new RuntimeException( "Expected a string value as sortkey" );
+			}
+
+			if ( ( $description = $this->findExtraDescriptionBy( $querySegment, $label, $order ) ) instanceof Description ) {
+				$extraDescriptions[] = $description;
+			}
+		}
+
+		return $extraDescriptions;
+	}
+
+	private function findExtraDescriptionBy( $querySegment, $label, $order ) {
+
+		$description = null;
+
+		// Is assigned, leave ...
+		if ( array_key_exists( $label, $querySegment->sortfields ) ) {
+			return $description;
+		}
+
+		// Find missing property to sort by.
+		if ( $label === '' ) { // Sort by first result column (page titles).
+			$querySegment->sortfields[$label] = "$querySegment->alias.smw_sort";
+		} elseif ( $label === '#' ) { // Sort by first result column (page titles).
+			// PHP7 showed a rather erratic behaviour where in cases
+			// the sortkey contains the same string for comparison, the
+			// result returned from the DB was mixed in order therefore
+			// using # as indicator to search for additional fields if
+			// no specific property is given (see test cases in #1534)
+			$querySegment->sortfields[$label] = "$querySegment->alias.smw_sort,$querySegment->alias.smw_title,$querySegment->alias.smw_subobject";
+		} elseif ( PropertyChainValue::isChained( $label ) ) { // Try to extend query.
+			$propertyChainValue = DataValueFactory::getInstance()->newDataValueByType( PropertyChainValue::TYPE_ID );
+			$propertyChainValue->setUserValue( $label );
+
+			if ( !$propertyChainValue->isValid() ) {
+				return $description;
+			}
+
+			$lastDataItem = $propertyChainValue->getLastPropertyChainValue()->getDataItem();
+
+			$description = $this->descriptionFactory->newSomeProperty(
+				$lastDataItem,
+				$this->descriptionFactory->newThingDescription()
+			);
+
+			// #2176, Set a different membership in case duplicate detection is
+			// enabled, the fingerprint will be distinguishable from a condition
+			// with another ThingDescription for the same property that would
+			// otherwise create a "Error: 1066 Not unique table/alias: 't3'"
+			$description->setMembership( $label );
+
+			foreach ( $propertyChainValue->getPropertyChainValues() as $val ) {
+				$description = $this->descriptionFactory->newSomeProperty(
+					$val->getDataItem(),
+					$description
+				);
+			}
+
+			// Add and replace Foo.Bar=asc with Bar=asc as we ultimately only
+			// order to the result of the last element
+			$this->sortKeys[$lastDataItem->getKey()] = $order;
+			unset( $this->sortKeys[$label] );
+		} else { // Try to extend query.
+			$sortprop = DataValueFactory::getInstance()->newPropertyValueByLabel( $label );
+
+			if ( $sortprop->isValid() ) {
+				$description = $this->descriptionFactory->newSomeProperty(
+					$sortprop->getDataItem(),
+					$this->descriptionFactory->newThingDescription()
+				);
+			}
+		}
+
+		return $description;
+	}
+
+	private function addConjunctionFromExtraDescriptions( $querySegment, array $extraDescriptions ) {
+
+		$this->querySegmentListBuilder->setSortKeys(
+			$this->sortKeys
+		);
+
+		$this->querySegmentListBuilder->getQuerySegmentFrom(
+			$this->descriptionFactory->newConjunction( $extraDescriptions )
+		);
+
+		// This is always an QuerySegment::Q_CONJUNCTION ...
+		$newQuerySegment = $this->querySegmentListBuilder->findQuerySegment(
+			$this->querySegmentListBuilder->getLastQuerySegmentId()
+		);
+
+		 // ... so just re-wire its dependencies
+		foreach ( $newQuerySegment->components as $cid => $field ) {
+			$querySegment->components[$cid] = $querySegment->joinfield;
+
+			if ( $this->asUnconditional ) {
+				$this->querySegmentListBuilder->findQuerySegment( $cid )->joinType = 'LEFT OUTER';
+			}
+
+			$querySegment->sortfields = array_merge(
+				$querySegment->sortfields,
+				$this->querySegmentListBuilder->findQuerySegment( $cid )->sortfields
+			);
+		}
+
+		$this->querySegmentListBuilder->addQuerySegment( $querySegment );
+	}
+
+}