Improved search query parser

diff --git a/wcfsetup/install/files/lib/system/search/SearchEngine.class.php b/wcfsetup/install/files/lib/system/search/SearchEngine.class.php
index 235da9ba1e679cbfc7e422c49b8cb9ec83b2903b..e3270c10606ad01c1d42e0478a57d84505c6830a 100644 (file)
--- a/wcfsetup/install/files/lib/system/search/SearchEngine.class.php
+++ b/wcfsetup/install/files/lib/system/search/SearchEngine.class.php
@@ -5,6 +5,7 @@ use wcf\system\database\util\PreparedStatementConditionBuilder;
 use wcf\system\exception\SystemException;
 use wcf\system\SingletonFactory;
 use wcf\system\WCF;
+use wcf\util\StringUtil;
 
 /**
  * SearchEngine searches for given query in the selected object types.
@@ -76,45 +77,7 @@ class SearchEngine extends SingletonFactory {
                $fulltextCondition = null;
                $relevanceCalc = '';
                if (!empty($q)) {
-                       // expand search terms with a * unless they're encapsulated with quotes
-                       $inQuotes = false;
-                       $tmp = '';
-                       $controlCharacterOrSpace = false;
-                       $chars = array('+', '-', '*');
-                       for ($i = 0, $length = mb_strlen($q); $i < $length; $i++) {
-                               $char = mb_substr($q, $i, 1);
-                               
-                               if ($inQuotes) {
-                                       if ($char == '"') {
-                                               $inQuotes = false;
-                                       }
-                               }
-                               else {
-                                       if ($char == '"') {
-                                               $inQuotes = true;
-                                       }
-                                       else {
-                                               if ($char == ' ' && !$controlCharacterOrSpace) {
-                                                       $controlCharacterOrSpace = true;
-                                                       $tmp .= '*';
-                                               }
-                                               else if (in_array($char, $chars)) {
-                                                       $controlCharacterOrSpace = true;
-                                               }
-                                               else {
-                                                       $controlCharacterOrSpace = false;
-                                               }
-                                       }
-                               }
-                               
-                               $tmp .= $char;
-                       }
-                       
-                       // handle last char
-                       if (!$inQuotes && !$controlCharacterOrSpace) {
-                               $tmp .= '*';
-                       }
-                       $q = $tmp;
+                       $q = $this->parseSearchQuery($q);
                        
                        $fulltextCondition = new PreparedStatementConditionBuilder(false);
                        switch (WCF::getDB()->getDBType()) {
@@ -206,4 +169,77 @@ class SearchEngine extends SingletonFactory {
                
                return $messages;
        }
+       
+       /**
+        * Manipulates the search term (< and > used as quotation marks):
+        * 
+        * - <test foo> becomes <+test* +foo*>
+        * - <test -foo bar> becomes <+test* -foo* +bar*>
+        * - <test "foo bar"> becomes <+test* +"foo bar">
+        * 
+        * @see http://dev.mysql.com/doc/refman/5.5/en/fulltext-boolean.html
+        * 
+        * @param       string          $query
+        */
+       protected function parseSearchQuery($query) {
+               $query = StringUtil::trim($query);
+               
+               // expand search terms with a * unless they're encapsulated with quotes
+               $inQuotes = false;
+               $previousChar = $tmp = '';
+               $controlCharacterOrSpace = false;
+               $chars = array('+', '-', '*');
+               for ($i = 0, $length = mb_strlen($query); $i < $length; $i++) {
+                       $char = mb_substr($query, $i, 1);
+                       
+                       if ($inQuotes) {
+                               if ($char == '"') {
+                                       $inQuotes = false;
+                               }
+                       }
+                       else {
+                               if ($char == '"') {
+                                       $inQuotes = true;
+                               }
+                               else {
+                                       if ($char == ' ' && !$controlCharacterOrSpace) {
+                                               $controlCharacterOrSpace = true;
+                                               $tmp .= '*';
+                                       }
+                                       else if (in_array($char, $chars)) {
+                                               $controlCharacterOrSpace = true;
+                                       }
+                                       else {
+                                               $controlCharacterOrSpace = false;
+                                       }
+                               }
+                       }
+                       
+                       /*
+                        * prepend a plus sign (logical AND) if ALL these conditions are given:
+                        * 
+                        * 1) previous character:
+                        *   - is empty (start of string)
+                        *   - is a space (MySQL uses spaces to separate words)
+                        * 
+                        * 2) not within quotation marks
+                        * 
+                        * 3) current char:
+                        *   - is NOT +, - or *
+                        */
+                       if (($previousChar == '' || $previousChar == ' ') && !$inQuotes && !in_array($char, $chars)) {
+                               $tmp .= '+';
+                       }
+                       
+                       $tmp .= $char;
+                       $previousChar = $char;
+               }
+               
+               // handle last char
+               if (!$inQuotes && !$controlCharacterOrSpace) {
+                       $tmp .= '*';
+               }
+               
+               return $tmp;
+       }
 }