1 files changed, 205 insertions, 0 deletions
diff --git a/www/wiki/extensions/SemanticMediaWiki/src/DataValues/ValueValidators/UniquenessConstraintValueValidator.php b/www/wiki/extensions/SemanticMediaWiki/src/DataValues/ValueValidators/UniquenessConstraintValueValidator.php
new file mode 100644
index 00000000..65ace8e3
--- /dev/null
+++ b/www/wiki/extensions/SemanticMediaWiki/src/DataValues/ValueValidators/UniquenessConstraintValueValidator.php
@@ -0,0 +1,205 @@
+<?php
+
+namespace SMW\DataValues\ValueValidators;
+
+use SMW\PropertySpecificationLookup;
+use SMW\DIWikiPage;
+use SMWDataValue as DataValue;
+use SMW\RequestOptions;
+use SMW\Store;
+
+/**
+ * @private
+ *
+ * Only allow values that are unique where uniqueness is establised for the first (
+ * in terms of time which also entails that after a full rebuild the first value
+ * found is being categorised as established value) value assigned to a property
+ * (that requires this trait) and any value that compares to an establised
+ * value with the same literal representation is being identified as violating the
+ * uniqueness constraint.
+ *
+ * @license GNU GPL v2+
+ * @since 2.4
+ *
+ * @author mwjames
+ */
+class UniquenessConstraintValueValidator implements ConstraintValueValidator {
+
+	/**
+	 * @var Store
+	 */
+	private $store;
+
+	/**
+	 * @var PropertySpecificationLookup
+	 */
+	private $propertySpecificationLookup;
+
+	/**
+	 * @var boolean
+	 */
+	private $hasConstraintViolation = false;
+
+	/**
+	 * Tracks annotations for the current context to verify that a subject only
+	 * contains unique assignments.
+	 *
+	 * @var array
+	 */
+	private static $annotations = [];
+
+	/**
+	 * @since 2.4
+	 *
+	 * @param Store $store
+	 * @param PropertySpecificationLookup $propertySpecificationLookup
+	 */
+	public function __construct( Store $store, PropertySpecificationLookup $propertySpecificationLookup ) {
+		$this->store = $store;
+		$this->propertySpecificationLookup = $propertySpecificationLookup;
+	}
+
+	/**
+	 * @since 2.4
+	 *
+	 * {@inheritDoc}
+	 */
+	public function hasConstraintViolation() {
+		return $this->hasConstraintViolation;
+	}
+
+	/**
+	 * @since 3.0
+	 *
+	 * {@inheritDoc}
+	 */
+	public function clear() {
+		self::$annotations = [];
+	}
+
+	/**
+	 * @since 2.4
+	 *
+	 * {@inheritDoc}
+	 */
+	public function validate( $dataValue ) {
+
+		$this->hasConstraintViolation = false;
+
+		if ( !$this->canValidate( $dataValue ) ) {
+			return $this->hasConstraintViolation;
+		}
+
+		$property = $dataValue->getProperty();
+
+		if ( !$this->propertySpecificationLookup->hasUniquenessConstraint( $property ) ) {
+			return $this->hasConstraintViolation;
+		}
+
+		$contextPage = $dataValue->getContextPage();
+
+		// Exclude the current page from the result match to check whether another
+		// page matches the condition and if so then the value can no longer be
+		// assigned and is not unique
+		$requestOptions = new RequestOptions();
+
+		$requestOptions->addExtraCondition( function( $store, $query, $alias ) use( $contextPage ) {
+				return $query->neq( "$alias.s_id", $store->getObjectIds()->getId( $contextPage ) );
+			}
+		);
+
+		$requestOptions->setLimit( 2 );
+		$count = 0;
+
+		if ( !$this->hasAnnotation( $dataValue ) ) {
+			$entityValueUniquenessConstraintChecker = $this->store->service( 'EntityValueUniquenessConstraintChecker' );
+
+			$res = $entityValueUniquenessConstraintChecker->checkConstraint(
+				$property,
+				$dataValue->getDataItem(),
+				$requestOptions
+			);
+
+			$count = count( $res );
+		}
+
+		// Check whether the current page has any other annotation for the
+		// same property
+		if ( $count < 1 && $this->isRegistered( $dataValue ) ) {
+			$dataValue->addErrorMsg(
+				[
+					'smw-datavalue-uniqueness-constraint-isknown',
+					$property->getLabel(),
+					$contextPage->getTitle()->getPrefixedText(),
+					$dataValue->getWikiValue()
+				]
+			);
+
+			$this->hasConstraintViolation = true;
+		}
+
+		// Has the page different values for the same property?
+		if ( $count < 1 ) {
+			return $this->hasConstraintViolation;
+		}
+
+		$this->hasConstraintViolation = true;
+
+		foreach ( $res as $dataItem ) {
+			$val = $dataValue->isValid() ? $dataValue->getWikiValue() : '...';
+			$text = '';
+
+			if ( $dataItem !== null && ( $title = $dataItem->getTitle() ) !== null ) {
+				$text = $title->getPrefixedText();
+			}
+
+			$dataValue->addErrorMsg(
+				[
+					'smw-datavalue-uniqueness-constraint-error',
+					$property->getLabel(),
+					$val,
+					$text
+				]
+			);
+		}
+
+		return $this->hasConstraintViolation;
+	}
+
+	private function canValidate( $dataValue ) {
+
+		if ( !$dataValue->isEnabledFeature( SMW_DV_PVUC ) || !$dataValue instanceof DataValue ) {
+			return false;
+		}
+
+		return $dataValue->getContextPage() !== null && $dataValue->getProperty() !== null;
+	}
+
+	private function isRegistered( $dataValue ) {
+
+		$contextPage = $dataValue->getContextPage();
+		$dataItem = $dataValue->getDataItem();
+		$property = $dataValue->getProperty();
+
+		$valueHash = md5( $property->getKey() . $dataItem->getHash() );
+		$key = $property->getKey();
+		$hash = $contextPage->getHash();
+
+		if ( isset( self::$annotations[$hash][$key] ) && self::$annotations[$hash][$key] !== $valueHash ) {
+			return true;
+		} else {
+			self::$annotations[$hash][$key] = $valueHash;
+		}
+
+		return false;
+	}
+
+	private function hasAnnotation( $dataValue ) {
+
+		$key = $dataValue->getProperty()->getKey();
+		$hash = $dataValue->getContextPage()->getHash();
+
+		return isset( self::$annotations[$hash][$key] );
+	}
+
+}