1 files changed, 116 insertions, 0 deletions
diff --git a/www/wiki/extensions/SemanticMediaWiki/src/DataValues/ValueValidators/PatternConstraintValueValidator.php b/www/wiki/extensions/SemanticMediaWiki/src/DataValues/ValueValidators/PatternConstraintValueValidator.php
new file mode 100644
index 00000000..d96e2656
--- /dev/null
+++ b/www/wiki/extensions/SemanticMediaWiki/src/DataValues/ValueValidators/PatternConstraintValueValidator.php
@@ -0,0 +1,116 @@
+<?php
+
+namespace SMW\DataValues\ValueValidators;
+
+use SMW\ApplicationFactory;
+use SMW\DataValues\ValueParsers\AllowsPatternValueParser;
+use SMWDataValue as DataValue;
+
+/**
+ * To support regular expressions in connection with the `Allows pattern`
+ * property.
+ *
+ * @license GNU GPL v2+
+ * @since 2.4
+ *
+ * @author mwjames
+ */
+class PatternConstraintValueValidator implements ConstraintValueValidator {
+
+	/**
+	 * @var AllowsPatternContentParser
+	 */
+	private $allowsPatternValueParser;
+
+	/**
+	 * @var boolean
+	 */
+	private $hasConstraintViolation = false;
+
+	/**
+	 * @since 2.4
+	 *
+	 * @param AllowsPatternValueParser $allowsPatternValueParser
+	 */
+	public function __construct( AllowsPatternValueParser $allowsPatternValueParser ) {
+		$this->allowsPatternValueParser = $allowsPatternValueParser;
+	}
+
+	/**
+	 * @since 2.4
+	 *
+	 * {@inheritDoc}
+	 */
+	public function hasConstraintViolation() {
+		return $this->hasConstraintViolation;
+	}
+
+	/**
+	 * @since 2.4
+	 *
+	 * {@inheritDoc}
+	 */
+	public function validate( $dataValue ) {
+
+		$this->hasConstraintViolation = false;
+
+		if (
+			!$dataValue instanceof DataValue ||
+			$dataValue->getProperty() === null ||
+			!$dataValue->isEnabledFeature( SMW_DV_PVAP ) ) {
+			return $this->hasConstraintViolation;
+		}
+
+		if ( ( $reference = ApplicationFactory::getInstance()->getPropertySpecificationLookup()->getAllowedPatternBy( $dataValue->getProperty() ) ) === '' ) {
+			return $this->hasConstraintViolation;
+		}
+
+		$content = $this->allowsPatternValueParser->parse(
+			$reference
+		);
+
+		if ( !$content ) {
+			return $this->hasConstraintViolation;
+		}
+
+		// Prevent a possible remote code execution vulnerability in connection
+		// with PCRE
+		$pattern = str_replace( [ '/e' ], [ '' ], trim( $content ) );
+
+		$this->doPregMatch(
+			$pattern,
+			$dataValue,
+			$reference
+		);
+	}
+
+	private function doPregMatch( $pattern, $dataValue, $reference ) {
+
+		// Convert escaping as in /\d{4}
+		$pattern = str_replace( "/\\", "\\", $pattern );
+
+		// Add a mandatory backslash
+		if ( $pattern !== '' && $pattern{0} !== '/' ) {
+			$pattern = '/' . $pattern;
+		}
+
+		if ( substr( $pattern, -1 ) !== '/' ) {
+			$pattern = $pattern . '/';
+		}
+
+		// @to suppress any errors caused by an invalid regex, the user should
+		// test the expression before making it available
+		if ( !@preg_match( $pattern, $dataValue->getDataItem()->getSortKey() ) ) {
+			$dataValue->addErrorMsg(
+				[
+					'smw-datavalue-allows-pattern-mismatch',
+					$dataValue->getWikiValue(),
+					$reference
+				]
+			);
+
+			$this->hasConstraintViolation = true;
+		}
+	}
+
+}