Search engine redesign, first part :

- new table #search to store search rules associated to a search id.

- search rules are not passed through GET anymore, the search array build in
  search.php is serialized in #search table, so no need to rebuild it in
  function include/functions_category.inc.php::category_initialize

- search array build code is improved (efficiency and layout) in search.php

- SQL related to search is build in a dedicated function
  include/functions::get_sql_search_clause

- direct search author:<...>, date_avalaible:<...>, date_creation:<...>,
  keywords:<...> from picture.php are not available anymore. They will come
  back later, with improvement (new design). Same for date_*:<> in calendar
  calendar category.


git-svn-id: http://piwigo.org/svn/trunk@1008 68402e56-0260-453c-a942-63ccdbb3a9ee

7 files changed, 374 insertions, 221 deletions

diff --git a/include/constants.php b/include/constants.php
index bb5a1d926..bf5cfd29c 100644
--- a/include/constants.php
+++ b/include/constants.php
@@ -60,4 +60,5 @@ define('RATE_TABLE', $prefixeTable.'rate');
 define('USER_CACHE_TABLE', $prefixeTable.'user_cache');
 define('CADDIE_TABLE', $prefixeTable.'caddie');
 define('UPGRADE_TABLE', $prefixeTable.'upgrade');
+define('SEARCH_TABLE', $prefixeTable.'search');
 ?>
diff --git a/include/functions.inc.php b/include/functions.inc.php
index 556c62582..f5710bbdd 100644
--- a/include/functions.inc.php
+++ b/include/functions.inc.php
@@ -741,8 +741,8 @@ function l10n($key)
 }
 
 /**
- * returns the corresponding value from $themeconf if existing. Else, the key is
- * returned
+ * returns the corresponding value from $themeconf if existing. Else, the
+ * key is returned
  *
  * @param string key
  * @return string
@@ -753,4 +753,186 @@ function get_themeconf($key)
 
   return $themeconf[$key];
 }
+
+/**
+ * Prepends and appends a string at each value of the given array.
+ *
+ * @param array
+ * @param string prefix to each array values
+ * @param string suffix to each array values
+ */
+function prepend_append_array_items($array, $prepend_str, $append_str)
+{
+  array_walk(
+    $array,
+    create_function('&$s', '$s = "'.$prepend_str.'".$s."'.$append_str.'";')
+    );
+
+  return $array;
+}
+
+/**
+ * returns the SQL clause from a search identifier
+ *
+ * Search rules are stored in search table as a serialized array. This array
+ * need to be transformed into an SQL clause to be used in queries.
+ *
+ * @param int search_id
+ * @return string
+ */
+function get_sql_search_clause($search_id)
+{
+  if (!is_numeric($search_id))
+  {
+    die('Search id must be an integer');
+  }
+  
+  $query = '
+SELECT rules
+  FROM '.SEARCH_TABLE.'
+  WHERE id = '.$_GET['search'].'
+;';
+  list($serialized_rules) = mysql_fetch_row(pwg_query($query));
+  
+  $search = unserialize($serialized_rules);
+
+//   echo '<pre>';
+//   print_r($search);
+//   echo '</pre>';
+
+  // SQL where clauses are stored in $clauses array during query
+  // construction
+  $clauses = array();
+  
+  foreach (array('file','name','comment','keywords','author') as $textfield)
+  {
+    if (isset($search['fields'][$textfield]))
+    {
+      $local_clauses = array();
+      foreach ($search['fields'][$textfield]['words'] as $word)
+      {
+        array_push($local_clauses, $textfield." LIKE '%".$word."%'");
+      }
+
+      // adds brackets around where clauses
+      $local_clauses = prepend_append_array_items($local_clauses, '(', ')');
+
+      array_push(
+        $clauses,
+        implode(
+          ' '.$search['fields'][$textfield]['mode'].' ',
+          $local_clauses
+          )
+        );
+    }
+  }
+  
+  if (isset($search['fields']['allwords']))
+  {
+    $fields = array('file', 'name', 'comment', 'keywords', 'author');
+    // in the OR mode, request bust be :
+    // ((field1 LIKE '%word1%' OR field2 LIKE '%word1%')
+    // OR (field1 LIKE '%word2%' OR field2 LIKE '%word2%'))
+    //
+    // in the AND mode :
+    // ((field1 LIKE '%word1%' OR field2 LIKE '%word1%')
+    // AND (field1 LIKE '%word2%' OR field2 LIKE '%word2%'))
+    $word_clauses = array();
+    foreach ($search['fields']['allwords']['words'] as $word)
+    {
+      $field_clauses = array();
+      foreach ($fields as $field)
+      {
+        array_push($field_clauses, $field." LIKE '%".$word."%'");
+      }
+      // adds brackets around where clauses
+      array_push(
+        $word_clauses,
+        implode(
+          "\n          OR ",
+          $field_clauses
+          )
+        );
+    }
+    
+    array_walk(
+      $word_clauses,
+      create_function('&$s','$s="(".$s.")";')
+      );
+    
+    array_push(
+      $clauses,
+      "\n         ".
+      implode(
+        "\n         ".
+              $search['fields']['allwords']['mode'].
+        "\n         ",
+        $word_clauses
+        )
+      );
+  }
+  
+  foreach (array('date_available', 'date_creation') as $datefield)
+  {
+    if (isset($search['fields'][$datefield]))
+    {
+      array_push(
+        $clauses,
+        $datefield." = '".$search['fields'][$datefield]['date']."'"
+        );
+    }
+    
+    foreach (array('after','before') as $suffix)
+    {
+      $key = $datefield.'-'.$suffix;
+      
+      if (isset($search['fields'][$key]))
+      {
+        array_push(
+          $clauses,
+          
+          $datefield.
+          ($suffix == 'after'             ? ' >' : ' <').
+          ($search['fields'][$key]['inc'] ? '='  : '').
+          " '".$search['fields'][$key]['date']."'"
+          
+          );
+      }
+    }
+  }
+  
+  if (isset($search['fields']['cat']))
+  {
+    if ($search['fields']['cat']['sub_inc'])
+    {
+      // searching all the categories id of sub-categories
+      $cat_ids = get_subcat_ids($search['fields']['cat']['words']);
+    }
+    else
+    {
+      $cat_ids = $search['fields']['cat']['words'];
+    }
+    
+    $local_clause = 'category_id IN ('.implode(',', $cat_ids).')';
+    array_push($clauses, $local_clause);
+  }
+  
+  // adds brackets around where clauses
+  $clauses = prepend_append_array_items($clauses, '(', ')');
+  
+  $where_separator =
+    implode(
+      "\n    ".$search['mode'].' ',
+      $clauses
+      );
+  
+  $search_clause = $where_separator;
+  
+  if (isset($forbidden))
+  {
+    $search_clause.= "\n    AND ".$forbidden;
+  }
+
+  return $search_clause;
+}
 ?>
diff --git a/include/functions_category.inc.php b/include/functions_category.inc.php
index 6b9618db1..c9fee76f0 100644
--- a/include/functions_category.inc.php
+++ b/include/functions_category.inc.php
@@ -103,7 +103,9 @@ function check_cat_id( $cat )
     {
       $page['cat'] = $cat;
     }
-    if ($cat == 'search' and isset($_GET['search']))
+    if ($cat == 'search'
+        and isset($_GET['search'])
+        and is_numeric($_GET['search']))
     {
       $page['cat'] = $cat;
     }
@@ -381,44 +383,6 @@ function initialize_category( $calling_page = 'category' )
       // search result
       if ( $page['cat'] == 'search' )
       {
-        // analyze search string given in URL (created in search.php)
-        $tokens = explode('|', $_GET['search']);
-
-        if (isset($tokens[1]) and $tokens[1] == 'AND')
-        {
-          $search['mode'] = 'AND';
-        }
-        else
-        {
-          $search['mode'] = 'OR';
-        }
-
-        $search_tokens = explode('--', $tokens[0]);
-        foreach ($search_tokens as $search_token)
-        {
-          $tokens = explode(':', $search_token);
-          $field_name = $tokens[0];
-          $field_content = $tokens[1];
-
-          $tokens = explode('~', $tokens[1]);
-          if (isset($tokens[1]))
-          {
-            $search['fields'][$field_name]['mode'] = $tokens[1];
-          }
-          else
-          {
-            $search['fields'][$field_name]['mode'] = '';
-          }
-
-          $search['fields'][$field_name]['words'] = array();
-          $tokens = explode(',', $tokens[0]);
-          foreach ($tokens as $token)
-          {
-            array_push($search['fields'][$field_name]['words'],
-                       htmlentities($token));
-          }
-        }
-        
         $page['title'] = $lang['search_result'];
         if ( $calling_page == 'picture' )
         {
@@ -426,117 +390,13 @@ function initialize_category( $calling_page = 'category' )
           $page['title'].= $_GET['search']."</span>";
         }
 
-        // SQL where clauses are stored in $clauses array during query
-        // construction
-        $clauses = array();
+        $page['where'] = 'WHERE '.get_sql_search_clause($_GET['search']);
         
-        $textfields = array('file', 'name', 'comment', 'keywords', 'author');
-        foreach ($textfields as $textfield)
-        {
-          if (isset($search['fields'][$textfield]))
-          {
-            $local_clauses = array();
-            foreach ($search['fields'][$textfield]['words'] as $word)
-            {
-              array_push($local_clauses, $textfield." LIKE '%".$word."%'");
-            }
-            // adds brackets around where clauses
-            array_walk($local_clauses,create_function('&$s','$s="(".$s.")";'));
-            array_push($clauses,
-                       implode(' '.$search['fields'][$textfield]['mode'].' ',
-                               $local_clauses));
-          }
-        }
-
-        if (isset($search['fields']['allwords']))
-        {
-          $fields = array('file', 'name', 'comment', 'keywords', 'author');
-          // in the OR mode, request bust be :
-          // ((field1 LIKE '%word1%' OR field2 LIKE '%word1%')
-          // OR (field1 LIKE '%word2%' OR field2 LIKE '%word2%'))
-          //
-          // in the AND mode :
-          // ((field1 LIKE '%word1%' OR field2 LIKE '%word1%')
-          // AND (field1 LIKE '%word2%' OR field2 LIKE '%word2%'))
-          $word_clauses = array();
-          foreach ($search['fields']['allwords']['words'] as $word)
-          {
-            $field_clauses = array();
-            foreach ($fields as $field)
-            {
-              array_push($field_clauses, $field." LIKE '%".$word."%'");
-            }
-            // adds brackets around where clauses
-            array_push($word_clauses, implode(' OR ', $field_clauses));
-          }
-          array_walk($word_clauses, create_function('&$s','$s="(".$s.")";'));
-          array_push($clauses,
-                     implode(' '.$search['fields']['allwords']['mode'].' ',
-                               $word_clauses));
-        }
-
-        $datefields = array('date_available', 'date_creation');
-        foreach ($datefields as $datefield)
-        {
-          $key = $datefield;
-          if (isset($search['fields'][$key]))
-          {
-            $local_clause = $datefield." = '";
-            $local_clause.= str_replace('.', '-',
-                                        $search['fields'][$key]['words'][0]);
-            $local_clause.= "'";
-            array_push($clauses, $local_clause);
-          }
-
-          foreach (array('after','before') as $suffix)
-          {
-            $key = $datefield.'-'.$suffix;
-            if (isset($search['fields'][$key]))
-            {
-              $local_clause = $datefield;
-              if ($suffix == 'after')
-              {
-                $local_clause.= ' >';
-              }
-              else
-              {
-                $local_clause.= ' <';
-              }
-              if (isset($search['fields'][$key]['mode'])
-                  and $search['fields'][$key]['mode'] == 'inc')
-              {
-                $local_clause.= '=';
-              }
-              $local_clause.= " '";
-              $local_clause.= str_replace('.', '-',
-                                          $search['fields'][$key]['words'][0]);
-              $local_clause.= "'";
-              array_push($clauses, $local_clause);
-            }
-          }
-        }
-
-        if (isset($search['fields']['cat']))
+        if (isset($forbidden))
         {
-          if ($search['fields']['cat']['mode'] == 'sub_inc')
-          {
-            // searching all the categories id of sub-categories
-            $cat_ids = get_subcat_ids($search['fields']['cat']['words']);
-          }
-          else
-          {
-            $cat_ids = $search['fields']['cat']['words'];
-          }
-          
-          $local_clause = 'category_id IN ('.implode(',', $cat_ids).')';
-          array_push($clauses, $local_clause);
+          $page['where'].= "\n    AND ".$forbidden;
         }
 
-        // adds brackets around where clauses
-        array_walk($clauses, create_function('&$s', '$s = "(".$s.")";'));
-        $page['where'] = 'WHERE '.implode(' '.$search['mode'].' ', $clauses);
-        if ( isset( $forbidden ) ) $page['where'].= ' AND '.$forbidden;
-
         $query = '
 SELECT COUNT(DISTINCT(id)) AS nb_total_images
   FROM '.IMAGES_TABLE.'
diff --git a/install/db/4-database.php b/install/db/4-database.php
new file mode 100644
index 000000000..c74486a46
--- /dev/null
+++ b/install/db/4-database.php
@@ -0,0 +1,54 @@
+<?php
+// +-----------------------------------------------------------------------+
+// | PhpWebGallery - a PHP based picture gallery                           |
+// | Copyright (C) 2002-2003 Pierrick LE GALL - pierrick@phpwebgallery.net |
+// | Copyright (C) 2003-2005 PhpWebGallery Team - http://phpwebgallery.net |
+// +-----------------------------------------------------------------------+
+// | branch        : BSF (Best So Far)
+// | file          : $RCSfile$
+// | last update   : $Date: 2005-09-21 00:04:57 +0200 (mer, 21 sep 2005) $
+// | last modifier : $Author: plg $
+// | revision      : $Revision: 870 $
+// +-----------------------------------------------------------------------+
+// | This program is free software; you can redistribute it and/or modify  |
+// | it under the terms of the GNU General Public License as published by  |
+// | the Free Software Foundation                                          |
+// |                                                                       |
+// | This program is distributed in the hope that it will be useful, but   |
+// | WITHOUT ANY WARRANTY; without even the implied warranty of            |
+// | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU      |
+// | General Public License for more details.                              |
+// |                                                                       |
+// | You should have received a copy of the GNU General Public License     |
+// | along with this program; if not, write to the Free Software           |
+// | Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, |
+// | USA.                                                                  |
+// +-----------------------------------------------------------------------+
+
+if (!defined('PHPWG_ROOT_PATH'))
+{
+  die('Hacking attempt!');
+}
+
+$upgrade_description = 'Table #search is required for search engine redesign';
+
+// +-----------------------------------------------------------------------+
+// |                            Upgrade content                            |
+// +-----------------------------------------------------------------------+
+
+// column user_id becomes data of type text
+$query = '
+CREATE TABLE '.PREFIX_TABLE.'search (
+  id int UNSIGNED NOT NULL AUTO_INCREMENT,
+  last_seen date DEFAULT NULL,
+  rules text,
+  PRIMARY KEY  (id)
+);';
+pwg_query($query);
+
+echo
+"\n"
+.'Table '.PREFIX_TABLE.'search created'
+."\n"
+;
+?>
diff --git a/install/phpwebgallery_structure.sql b/install/phpwebgallery_structure.sql
index 12a27c00d..9e50885f6 100644
--- a/install/phpwebgallery_structure.sql
+++ b/install/phpwebgallery_structure.sql
@@ -177,6 +177,18 @@ CREATE TABLE `phpwebgallery_rate` (
 ) TYPE=MyISAM;
 
 --
+-- Table structure for table `phpwebgallery_search`
+--
+
+DROP TABLE IF EXISTS `phpwebgallery_search`;
+CREATE TABLE `phpwebgallery_search` (
+  `id` int(10) unsigned NOT NULL auto_increment,
+  `last_seen` date default NULL,
+  `rules` text,
+  PRIMARY KEY  (`id`)
+) TYPE=MyISAM;
+
+--
 -- Table structure for table `phpwebgallery_sessions`
 --
 
diff --git a/picture.php b/picture.php
index f34c6b3c3..a9655f712 100644
--- a/picture.php
+++ b/picture.php
@@ -675,10 +675,14 @@ $infos = array();
 if (!empty($picture['current']['author']))
 {
   $infos['INFO_AUTHOR'] =
-    '<a href="'.
-      PHPWG_ROOT_PATH.'category.php?cat=search'.
-      '&amp;search=author:'.$picture['current']['author']
-      .'">'.$picture['current']['author'].'</a>';
+    // FIXME because of search engine partial rewrite, giving the author
+    // name threw GET is not supported anymore. This feature should come
+    // back later, with a better design
+//     '<a href="'.
+//       PHPWG_ROOT_PATH.'category.php?cat=search'.
+//       '&amp;search=author:'.$picture['current']['author']
+//       .'">'.$picture['current']['author'].'</a>';
+    $picture['current']['author'];
 }
 else
 {
@@ -689,10 +693,14 @@ else
 if (!empty($picture['current']['date_creation']))
 {
   $infos['INFO_CREATION_DATE'] =
-    '<a href="'.
-      PHPWG_ROOT_PATH.'category.php?cat=search'.
-      '&amp;search=date_creation:'.$picture['current']['date_creation']
-      .'">'.format_date($picture['current']['date_creation']).'</a>';
+    // FIXME because of search engine partial rewrite, giving the author
+    // name threw GET is not supported anymore. This feature should come
+    // back later, with a better design (calendar view).
+//     '<a href="'.
+//       PHPWG_ROOT_PATH.'category.php?cat=search'.
+//       '&amp;search=date_creation:'.$picture['current']['date_creation']
+//       .'">'.format_date($picture['current']['date_creation']).'</a>';
+    format_date($picture['current']['date_creation']);
 }
 else
 {
@@ -701,13 +709,18 @@ else
 
 // date of availability
 $infos['INFO_AVAILABILITY_DATE'] =
-  '<a href="'.
-    PHPWG_ROOT_PATH.'category.php?cat=search'.
-    '&amp;search=date_available:'.
-    substr($picture['current']['date_available'], 0, 10)
-    .'">'.
-  format_date($picture['current']['date_available'], 'mysql_datetime').
-  '</a>';
+// FIXME because of search engine partial rewrite, giving the author
+// name threw GET is not supported anymore. This feature should come
+// back later, with a better design (calendar view).
+//
+//   '<a href="'.
+//     PHPWG_ROOT_PATH.'category.php?cat=search'.
+//     '&amp;search=date_available:'.
+//     substr($picture['current']['date_available'], 0, 10)
+//     .'">'.
+//   format_date($picture['current']['date_available'], 'mysql_datetime').
+//   '</a>';
+format_date($picture['current']['date_available'], 'mysql_datetime');
 
 // size in pixels
 if ($picture['current']['is_picture'])
@@ -751,13 +764,17 @@ $infos['INFO_FILE'] = $picture['current']['file'];
 if (!empty($picture['current']['keywords']))
 {
   $infos['INFO_KEYWORDS'] =
-    preg_replace(
-      '/([^,]+)/',
-      '<a href="'.
-        PHPWG_ROOT_PATH.'category.php?cat=search&amp;search=keywords:$1'
-        .'">$1</a>',
-      $picture['current']['keywords']
-      );
+    // FIXME because of search engine partial rewrite, giving the author
+    // name threw GET is not supported anymore. This feature should come
+    // back later, with a better design (tag classification).
+//     preg_replace(
+//       '/([^,]+)/',
+//       '<a href="'.
+//         PHPWG_ROOT_PATH.'category.php?cat=search&amp;search=keywords:$1'
+//         .'">$1</a>',
+//       $picture['current']['keywords']
+//       );
+    $picture['current']['keywords'];
 }
 else
 {
diff --git a/search.php b/search.php
index b02b52daa..a61526d7b 100644
--- a/search.php
+++ b/search.php
@@ -37,41 +37,43 @@ if (isset($_POST['submit']))
 {
   if (isset($_POST['search_allwords'])
       and !preg_match('/^\s*$/', $_POST['search_allwords']))
-  {
-    $local_search = array();
-    $search_allwords = $_POST['search_allwords'];
+  {    
     $drop_char_match = array(
       '-','^','$',';','#','&','(',')','<','>','`','\'','"','|',',','@','_',
       '?','%','~','.','[',']','{','}',':','\\','/','=','\'','!','*');
     $drop_char_replace = array(
       ' ',' ',' ',' ',' ',' ',' ',' ',' ',' ','','',' ',' ',' ',' ','',' ',
       ' ',' ',' ',' ',' ',' ',' ',' ','' ,' ',' ',' ',' ',' ');
-    $search_allwords = str_replace($drop_char_match,
-                                   $drop_char_replace,
-                                   $search_allwords);
 	
     // Split words
-    $words = preg_split('/\s+/', $search_allwords);
-    $words = array_unique($words);
-    $search['fields']['allwords'] = array();
-    $search['fields']['allwords']['words'] = $words;
-    $search['fields']['allwords']['mode'] = $_POST['mode'];
+    $search['fields']['allwords'] = array(
+      'words' => array_unique(
+        preg_split(
+          '/\s+/',
+          str_replace(
+            $drop_char_match,
+            $drop_char_replace,
+            $_POST['search_allwords']
+            )
+          )
+        ),
+      'mode' => $_POST['mode'],
+      );
   }
   
   if ($_POST['search_author'])
   {
-    $search['fields']['author'] = array();
-    $search['fields']['author']['words'] = array($_POST['search_author']);
+    $search['fields']['author'] = array(
+      'words' => array($_POST['search_author']),
+      );
   }
   
   if (isset($_POST['cat']))
   {
-    $search['fields']['cat'] = array();
-    $search['fields']['cat']['words'] = $_POST['cat'];
-    if ($_POST['subcats-included'] == 1)
-    {
-      $search['fields']['cat']['mode'] = 'sub_inc';
-    }
+    $search['fields']['cat'] = array(
+      'words'   => $_POST['cat'],
+      'sub_inc' => ($_POST['subcats-included'] == 1) ? true : false,
+      );
   }
 
   // dates
@@ -79,46 +81,71 @@ if (isset($_POST['submit']))
   
   if (!empty($_POST['start_year']))
   {
-    $year = $_POST['start_year'];
-    $month = $_POST['start_month'] != 0 ? $_POST['start_month'] : '01';
-    $day = $_POST['start_day'] != 0 ? $_POST['start_day'] : '01';
-    $date = $year.'-'.$month.'-'.$day;
+//     $year = $_POST['start_year'];
+//     $month = $_POST['start_month'] != 0 ? $_POST['start_month'] : '01';
+//     $day = $_POST['start_day'] != 0 ? $_POST['start_day'] : '01';
+//     $date = $year.'-'.$month.'-'.$day;
     
-    $search['fields'][$type_date.'-after']['words'] = array($date);
-    $search['fields'][$type_date.'-after']['mode'] = 'inc';
+//     $search['fields'][$type_date.'-after']['words'] = array($date);
+//     $search['fields'][$type_date.'-after']['mode'] = 'inc';
+
+    $search['fields'][$type_date.'-after'] = array(
+      'date' => join(
+        '-',
+        array(
+          $_POST['start_year'],
+          $_POST['start_month'] != 0 ? $_POST['start_month'] : '01',
+          $_POST['start_day']   != 0 ? $_POST['start_day']   : '01',
+          )
+        ),
+      'inc' => true,
+      );
   }
 
   if (!empty($_POST['end_year']))
   {
-    $year = $_POST['end_year'];
-    $month = $_POST['end_month'] != 0 ? $_POST['end_month'] : '12';
-    $day = $_POST['end_day'] != 0 ? $_POST['end_day'] : '31';
-    $date = $year.'-'.$month.'-'.$day;
+//     $year = $_POST['end_year'];
+//     $month = $_POST['end_month'] != 0 ? $_POST['end_month'] : '12';
+//     $day = $_POST['end_day'] != 0 ? $_POST['end_day'] : '31';
+//     $date = $year.'-'.$month.'-'.$day;
     
-    $search['fields'][$type_date.'-before']['words'] = array($date);
-    $search['fields'][$type_date.'-before']['mode'] = 'inc';
+    $search['fields'][$type_date.'-before'] = array(
+      'date' => join(
+        '-',
+        array(
+          $_POST['end_year'],
+          $_POST['end_month'] != 0 ? $_POST['end_month'] : '12',
+          $_POST['end_day']   != 0 ? $_POST['end_day']   : '31',
+          )
+        ),
+      'inc' => true,
+      );
   }
-    
-  // search string (for URL) creation
-  $search_string = '';
-  $tokens = array();
+  
   if (!empty($search))
   {
-    foreach (array_keys($search['fields']) as $field)
-    {
-      $token = $field.':';
-      $token.= implode(',', $search['fields'][$field]['words']);
-      if (isset($search['fields'][$field]['mode']))
-      {
-        $token.= '~'.$search['fields'][$field]['mode'];
-      }
-      array_push($tokens, $token);
-    }
-    $search_string.= implode('--', $tokens);
-    if (count($tokens) > 1)
-    {
-      $search_string.= '|AND';
-    }
+    // default search mode : each clause must be respected
+    $search['mode'] = 'AND';
+
+//     echo '<pre>';
+//     print_r($_POST);
+//     echo '</pre>';
+
+//     echo '<pre>';
+//     print_r($search);
+//     echo '</pre>';
+    
+    // register search rules in database, then they will be available on
+    // thumbnails page and picture page.
+    $query ='
+INSERT INTO '.SEARCH_TABLE.'
+  (rules)
+  VALUES
+  (\''.serialize($search).'\')
+;';
+    pwg_query($query);
+
+    $search_id = mysql_insert_id();
   }
   else
   {
@@ -128,7 +155,7 @@ if (isset($_POST['submit']))
 //----------------------------------------------------------------- redirection
 if (isset($_POST['submit']) and count($errors) == 0)
 {
-  $url = 'category.php?cat=search&search='.$search_string;
+  $url = 'category.php?cat=search&search='.$search_id;
   redirect($url);
 }
 //----------------------------------------------------- template initialization