Index: trunk/core/units/general/helpers/search_helper.php
===================================================================
diff -u -r4225 -r4228
--- trunk/core/units/general/helpers/search_helper.php	(.../search_helper.php)	(revision 4225)
+++ trunk/core/units/general/helpers/search_helper.php	(.../search_helper.php)	(revision 4228)
@@ -12,17 +12,76 @@
 		function splitKeyword($keyword)
 		{
 			$quotes_re = '/([+\-]?)"(.*?)"/';
-			$no_qutes_re = '/([+\-]?)([^ ]+)/';
+			$no_quotes_re = '/([+\-]?)([^ ]+)/';
 			
 			$quoted_kw = preg_match_all($quotes_re, $keyword, $res);
 			foreach ($res[2] as $index => $kw) $final[$kw] = $res[1][$index];
 			$keyword = preg_replace($quotes_re, '', $keyword);
-			$not_quoted_kw =  preg_match_all($no_qutes_re, $keyword, $res);
+			$not_quoted_kw =  preg_match_all($no_quotes_re, $keyword, $res);
 			foreach ($res[2] as $index => $kw) $final[$kw] = $res[1][$index];
 			
 			return $final;
 		}
 		
+		function getPositiveKeywords($keyword)
+		{
+			$keywords = $this->splitKeyword($keyword);
+			
+			$ret = Array();
+			foreach ($keywords as $keyword => $sign) {
+				if ($sign == '+' || $sign == '') {
+					$ret[] = $keyword;
+				}
+			}
+			return $ret;
+		}
+		
+		function buildWhereClause($keyword, $fields)
+		{
+			$keywords = $this->splitKeyword($keyword);
+			
+			$normal_conditions = Array();
+			$plus_conditions = Array();
+			$minus_conditions = Array();
+			
+			foreach ($keywords as $keyword => $sign) {
+				switch ($sign) {
+					case '+':
+						$plus_conditions[] =   implode(' LIKE "%'.$keyword.'%" OR ', $fields).' LIKE "%'.$keyword.'%"';
+						break;
+						
+					case '-':
+						foreach ($fields as $field) {
+							$condition[] = $field.' NOT LIKE "%'.$keyword.'%" OR '.$field.' IS NULL';
+						}
+						$minus_conditions[] = '('.implode(') AND (', $condition).')';
+						break;
+						
+					case '':
+						$normal_conditions[] = implode(' LIKE "%'.$keyword.'%" OR ', $fields).' LIKE "%'.$keyword.'%"';
+						break;
+				}
+			}
+	
+			// building where clause
+			if ($normal_conditions) {
+				$where_clause = '('.implode(') OR (', $normal_conditions).')';
+			}
+			else {
+				$where_clause = '1';
+			}
+			
+			if ($plus_conditions) {
+				$where_clause = '('.$where_clause.') AND ('.implode(') AND (', $plus_conditions).')';
+			}
+			
+			if ($minus_conditions) {
+				$where_clause = '('.$where_clause.') AND ('.implode(') AND (', $minus_conditions).')';
+			}
+			
+			return $where_clause;
+		}
+		
 	}
 
 ?>
\ No newline at end of file