1 files changed, 193 insertions, 0 deletions
diff --git a/www/wiki/extensions/SemanticMediaWiki/src/Query/QueryComparator.php b/www/wiki/extensions/SemanticMediaWiki/src/Query/QueryComparator.php
new file mode 100644
index 00000000..f2fb168f
--- /dev/null
+++ b/www/wiki/extensions/SemanticMediaWiki/src/Query/QueryComparator.php
@@ -0,0 +1,193 @@
+<?php
+
+namespace SMW\Query;
+
+/**
+ * @license GNU GPL v2+
+ * @since 1.5.3
+ *
+ * @author mwjames
+ * @author Jeroen De Dauw
+ */
+class QueryComparator {
+
+	/**
+	 * @var QueryComparator
+	 */
+	private static $instance = null;
+
+	/**
+	 * @var array
+	 */
+	private $comparators = null;
+
+	/**
+	 * @var array
+	 */
+	private $reverseCache = [];
+
+	/**
+	 * @since 2.3
+	 *
+	 * @param string $comparatorList
+	 * @param boolean $strictComparators
+	 */
+	public function __construct( $comparatorList, $strictComparators ) {
+		$this->comparators = $this->getEnabledComparators( $comparatorList, $strictComparators );
+	}
+
+	/**
+	 * @since 2.3
+	 *
+	 * @return self
+	 */
+	public static function getInstance() {
+
+		if ( self::$instance === null ) {
+			self::$instance = new self(
+				$GLOBALS['smwgQComparators'],
+				$GLOBALS['smwStrictComparators']
+			);
+		}
+
+		return self::$instance;
+	}
+
+	/**
+	 * @since 2.3
+	 */
+	public static function clear() {
+		self::$instance = null;
+	}
+
+	/**
+	 * Gets an array with all supported comparator strings.
+	 * The string for SMW_CMP_EQ, which is an empty string, is not in this list.
+	 *
+	 * @since 1.5.3
+	 *
+	 * @return array
+	 */
+	public function getComparatorStrings() {
+		return array_keys( $this->comparators );
+	}
+
+	/**
+	 * Gets the SMW_CMP_ for a string comparator, falling back to the
+	 * $defaultComparator when none is found.
+	 *
+	 * @since 1.5.3
+	 *
+	 * @param string $string
+	 * @param integer $defaultComparator Item of the SMW_CMP_ enum
+	 *
+	 * @return integer Item of the SMW_CMP_ enum
+	 */
+	public function getComparatorFromString( $string, $defaultComparator = SMW_CMP_EQ ) {
+
+		if ( $string === '' ) {
+			return SMW_CMP_EQ;
+		}
+
+		return array_key_exists( $string, $this->comparators ) ? $this->comparators[$string] : $defaultComparator;
+	}
+
+	/**
+	 * @since 2.5
+	 *
+	 * @param string $value
+	 * @param integer $comparator
+	 *
+	 * @return boolean
+	 */
+	public function containsComparator( $value, $comparator = SMW_CMP_EQ ) {
+		return $this->extractComparatorFromString( $value ) === $comparator;
+	}
+
+	/**
+	 * Extract possible comparators from a value and alter it to consist
+	 * only of the remaining effective value string (without the comparator).
+	 *
+	 * @since 2.4
+	 *
+	 * @param $value
+	 *
+	 * @return integer
+	 */
+	public function extractComparatorFromString( &$value ) {
+
+		$comparator = SMW_CMP_EQ;
+
+		foreach ( $this->getComparatorStrings() as $string ) {
+			if ( strpos( $value, $string ) === 0 ) {
+				$comparator = $this->getComparatorFromString( substr( $value, 0, strlen( $string ) ) );
+				$value = substr( $value, strlen( $string ) );
+				break;
+			}
+		}
+
+		return $comparator;
+	}
+
+	/**
+	 * Gets the comparator string for a comparator.
+	 *
+	 * @since 1.5.3
+	 *
+	 * @param $comparator
+	 *
+	 * @return string
+	 */
+	public function getStringForComparator( $comparator ) {
+
+		if ( $this->reverseCache === [] ) {
+			$this->reverseCache = array_flip( $this->comparators );
+		}
+
+		if ( $comparator == SMW_CMP_EQ ) {
+			return '';
+		} elseif ( array_key_exists( $comparator, $this->reverseCache ) ) {
+			return $this->reverseCache[$comparator];
+		}
+
+		throw new Exception( "Comparator $comparator does not have a string representatation" );
+	}
+
+	private function getEnabledComparators( $comparatorList, $strictComparators ) {
+
+		// Note: Comparators that contain other comparators at the beginning of
+		// the string need to be at beginning of the array.
+		$comparators = [
+			'like:' => SMW_CMP_PRIM_LIKE,
+			'nlike:' => SMW_CMP_PRIM_NLKE,
+			'in:' => SMW_CMP_IN,
+			'not:' => SMW_CMP_NOT,
+			'phrase:' => SMW_CMP_PHRASE,
+			'!~' => SMW_CMP_NLKE,
+			'<<' => SMW_CMP_LESS,
+			'>>' => SMW_CMP_GRTR,
+			'<' => $strictComparators ? SMW_CMP_LESS : SMW_CMP_LEQ,
+			'>' => $strictComparators ? SMW_CMP_GRTR : SMW_CMP_GEQ,
+			'≤' => SMW_CMP_LEQ,
+			'≥' => SMW_CMP_GEQ,
+			'!' => SMW_CMP_NEQ,
+			'~' => SMW_CMP_LIKE,
+		];
+
+		if ( strpos( $comparatorList, '|' ) === false ) {
+			return $comparators;
+		}
+
+		$allowedComparators = explode( '|', $comparatorList );
+
+		// Remove the comparators that are not allowed.
+		foreach ( $comparators as $string => $comparator ) {
+			if ( !in_array( $string, $allowedComparators ) ) {
+				unset( $comparators[$string] );
+			}
+		}
+
+		return $comparators;
+	}
+
+}