improvement: tags replace keywords. Better data model, less

limitations. Each image can be associated to as many tag as needed. Tags can
contain non ASCII characters. Oriented navigation with tags by association.


git-svn-id: http://piwigo.org/svn/trunk@1119 68402e56-0260-453c-a942-63ccdbb3a9ee

8 files changed, 594 insertions, 154 deletions

diff --git a/admin.php b/admin.php
index fa9a23cc0..6617dfadc 100644
--- a/admin.php
+++ b/admin.php
@@ -92,6 +92,7 @@ $template->assign_vars(
     'U_COMMENTS'=> $link_start.'comments',
     'U_RATING'=> $link_start.'rating',
     'U_CADDIE'=> $link_start.'element_set&cat=caddie',
+    'U_TAGS'=> $link_start.'tags',
     'U_THUMBNAILS'=> $link_start.'thumbnail',
     'U_USERS'=> $link_start.'user_list',
     'U_GROUPS'=> $link_start.'group_list',
diff --git a/admin/element_set_global.php b/admin/element_set_global.php
index 61ef2d6ee..f4b8aae2b 100644
--- a/admin/element_set_global.php
+++ b/admin/element_set_global.php
@@ -44,40 +44,6 @@ include_once(PHPWG_ROOT_PATH.'admin/include/functions.php');
 check_status(ACCESS_ADMINISTRATOR);
 
 // +-----------------------------------------------------------------------+
-// |                               functions                               |
-// +-----------------------------------------------------------------------+
-
-/**
- * returns the list of uniq keywords among given elements
- *
- * @param array element_ids
- */
-function get_elements_keywords($element_ids)
-{
-  if (0 == count($element_ids))
-  {
-    return array();
-  }
-
-  $keywords = array();
-
-  $query = '
-SELECT keywords
-  FROM '.IMAGES_TABLE.'
-  WHERE id IN ('.implode(',', $element_ids).')
-;';
-  $result = pwg_query($query);
-  while ($row = mysql_fetch_array($result))
-  {
-    if (isset($row['keywords']) and !empty($row['keywords']))
-    {
-      $keywords = array_merge($keywords, explode(',', $row['keywords']));
-    }
-  }
-  return array_unique($keywords);
-}
-
-// +-----------------------------------------------------------------------+
 // |                       global mode form submission                     |
 // +-----------------------------------------------------------------------+
 
@@ -111,6 +77,22 @@ if (isset($_POST['submit']))
     }
   }
 
+  if (isset($_POST['add_tags']) and count($collection) > 0)
+  {
+    add_tags($_POST['add_tags'], $collection);
+  }
+
+  if (isset($_POST['del_tags']) and count($collection) > 0)
+  {
+    $query = '
+DELETE
+  FROM '.IMAGE_TAG_TABLE.'
+  WHERE image_id IN ('.implode(',', $collection).')
+    AND tag_id IN ('.implode(',', $_POST['del_tags']).')
+;';
+    pwg_query($query);
+  }
+  
   if ($_POST['associate'] != 0 and count($collection) > 0)
   {
     $datas = array();
@@ -192,11 +174,6 @@ DELETE
   $datas = array();
   $dbfields = array('primary' => array('id'), 'update' => array());
 
-  if (!empty($_POST['add_keywords']) or $_POST['remove_keyword'] != '0')
-  {
-    array_push($dbfields['update'], 'keywords');
-  }
-
   $formfields = array('author', 'name', 'date_creation');
   foreach ($formfields as $formfield)
   {
@@ -210,7 +187,7 @@ DELETE
   if (count($dbfields['update']) > 0 and count($collection) > 0)
   {
     $query = '
-SELECT id, keywords
+SELECT id
   FROM '.IMAGES_TABLE.'
   WHERE id IN ('.implode(',', $collection).')
 ;';
@@ -221,44 +198,6 @@ SELECT id, keywords
       $data = array();
       $data['id'] = $row['id'];
 
-      if (!empty($_POST['add_keywords']))
-      {
-        $data['keywords'] =
-          implode(
-            ',',
-            array_unique(
-              array_merge(
-                get_keywords(empty($row['keywords']) ? '' : $row['keywords']),
-                get_keywords($_POST['add_keywords'])
-                )
-              )
-            );
-      }
-
-      if ($_POST['remove_keyword'] != '0')
-      {
-        if (!isset($data['keywords']))
-        {
-          $data['keywords'] = empty($row['keywords']) ? '' : $row['keywords'];
-        }
-
-        $data['keywords'] =
-          implode(
-            ',',
-            array_unique(
-              array_diff(
-                get_keywords($data['keywords']),
-                array($_POST['remove_keyword'])
-                )
-              )
-            );
-
-        if ($data['keywords'] == '')
-        {
-          unset($data['keywords']);
-        }
-      }
-
       if ('set' == $_POST['author_action'])
       {
         $data['author'] = $_POST['author'];
@@ -384,25 +323,36 @@ SELECT DISTINCT(category_id) AS id, c.name, uppercats, global_rank
   display_select_cat_wrapper($query, array(), $blockname, true);
 }
 
-$blockname = 'remove_keyword_option';
-
-$template->assign_block_vars(
-  $blockname,
-  array('VALUE'=> 0,
-        'OPTION' => '------------'
-    ));
+// add tags
+$template->assign_vars(
+  array(
+    'ADD_TAG_SELECTION' => get_html_tag_selection(get_all_tags(), 'add_tags'),
+    )
+  );
 
-$keywords = get_elements_keywords($page['cat_elements_id']);
+// remove tags
+$query = '
+SELECT tag_id, name, url_name, count(*) counter
+  FROM '.IMAGE_TAG_TABLE.'
+    INNER JOIN '.TAGS_TABLE.' ON tag_id = id
+  WHERE image_id IN ('.implode(',', $page['cat_elements_id']).')
+  GROUP BY tag_id
+  ORDER BY name ASC
+;';
+$result = pwg_query($query);
 
-foreach ($keywords as $keyword)
+$tags = array();
+while($row = mysql_fetch_array($result))
 {
-  $template->assign_block_vars(
-  $blockname,
-  array('VALUE'=> $keyword,
-        'OPTION' => $keyword
-    ));
+  array_push($tags, $row);
 }
 
+$template->assign_vars(
+  array(
+    'DEL_TAG_SELECTION' => get_html_tag_selection($tags, 'del_tags'),
+    )
+  );
+
 // creation date
 $day =
 empty($_POST['date_creation_day']) ? date('j') : $_POST['date_creation_day'];
diff --git a/admin/element_set_unit.php b/admin/element_set_unit.php
index c43522894..f6800f399 100644
--- a/admin/element_set_unit.php
+++ b/admin/element_set_unit.php
@@ -103,25 +103,21 @@ SELECT id, date_creation
     {
       $data{'date_creation'} = $row['date_creation'];
     }
+    
+    array_push($datas, $data);
 
-    $keywords = get_keywords($_POST['keywords-'.$row['id']]);
-    if (count($keywords) > 0)
-    {
-      $data{'keywords'} = implode(',', $keywords);
-    }
-    else
+    // tags management
+    if (isset($_POST[ 'tags-'.$row['id'] ]))
     {
-      $data{'keywords'} = '';
+      set_tags($_POST[ 'tags-'.$row['id'] ], $row['id']);
     }
-
-    array_push($datas, $data);
   }
   
   mass_updates(
     IMAGES_TABLE,
     array(
       'primary' => array('id'),
-      'update' => array('name','author','comment','date_creation','keywords')
+      'update' => array('name','author','comment','date_creation')
       ),
     $datas
     );
@@ -192,11 +188,13 @@ if (count($page['cat_elements_id']) > 0)
     );
   $template->assign_vars(array('NAV_BAR' => $nav_bar));
 
+  // tags
+  $all_tags = get_all_tags();
  
   $element_ids = array();
 
   $query = '
-SELECT id,path,tn_ext,name,date_creation,comment,keywords,author,file
+SELECT id,path,tn_ext,name,date_creation,comment,author,file
   FROM '.IMAGES_TABLE.'
   WHERE id IN ('.implode(',', $page['cat_elements_id']).')
   '.$conf['order_by'].'
@@ -210,6 +208,13 @@ SELECT id,path,tn_ext,name,date_creation,comment,keywords,author,file
     array_push($element_ids, $row['id']);
     
     $src = get_thumbnail_src($row['path'], @$row['tn_ext']);
+
+    $query = '
+SELECT tag_id
+  FROM '.IMAGE_TAG_TABLE.'
+  WHERE image_id = '.$row['id'].'
+;';
+    $selected_tags = array_from_query($query, 'tag_id');
     
     // creation date
     if (!empty($row['date_creation']))
@@ -237,7 +242,12 @@ SELECT id,path,tn_ext,name,date_creation,comment,keywords,author,file
         'AUTHOR' => @$row['author'],
         'DESCRIPTION' => @$row['comment'],
         'DATE_CREATION_YEAR' => $year,
-        'KEYWORDS' => @$row['keywords']
+        
+        'TAG_SELECTION' => get_html_tag_selection(
+          $all_tags,
+          'tags-'.$row['id'],
+          $selected_tags
+          ),
         )
       );
     
diff --git a/admin/include/functions.php b/admin/include/functions.php
index dc477f6d1..3a8c6b506 100644
--- a/admin/include/functions.php
+++ b/admin/include/functions.php
@@ -269,6 +269,14 @@ DELETE FROM '.IMAGE_CATEGORY_TABLE.'
 ;';
   pwg_query($query);
 
+  // destruction of the links between images and tags
+  $query = '
+DELETE FROM '.IMAGE_TAG_TABLE.'
+  WHERE image_id IN (
+'.wordwrap(implode(', ', $ids), 80, "\n").')
+;';
+  pwg_query($query);
+
   // destruction of the favorites associated with the picture
   $query = '
 DELETE FROM '.FAVORITES_TABLE.'
@@ -577,25 +585,6 @@ function date_convert_back( $date )
 }
 
 /**
- * returns an array with relevant keywords found in the given string.
- *
- * Keywords must be separated by comma or space characters.
- *
- * @param string keywords_string
- * @return array
- */
-function get_keywords($keywords_string)
-{
-  return
-    array_unique(
-      preg_split(
-        '/[\s,]+/',
-        $keywords_string
-        )
-      );
-}
-
-/**
  * returns an array containing sub-directories which can be a category,
  * recursive by default
  *
@@ -2094,6 +2083,173 @@ UPDATE
 }
 
 /**
+ * Set tags to an image. Warning: given tags are all tags associated to the
+ * image, not additionnal tags.
+ *
+ * @param array tag ids
+ * @param int image id
+ * @return void
+ */
+function set_tags($tags, $image_id)
+{
+  $query = '
+DELETE
+  FROM '.IMAGE_TAG_TABLE.'
+  WHERE image_id = '.$image_id.'
+;';
+  pwg_query($query);
+
+  if (count($tags) > 0)
+  {
+    $inserts = array();
+    foreach ($tags as $tag_id)
+    {
+      array_push(
+        $inserts,
+        array(
+          'tag_id' => $tag_id,
+          'image_id' => $image_id
+          )
+        );
+    }
+    mass_inserts(
+      IMAGE_TAG_TABLE,
+      array_keys($inserts[0]),
+      $inserts
+      );
+  }
+}
+
+/**
+ * Add new tags to a set of images.
+ *
+ * @param array tag ids
+ * @param array image ids
+ * @return void
+ */
+function add_tags($tags, $images)
+{
+  if (count($tags) == 0 or count($tags) == 0)
+  {
+    return;
+  }
+  
+  // we can't insert twice the same {image_id,tag_id} so we must first
+  // delete lines we'll insert later
+  $query = '
+DELETE
+  FROM '.IMAGE_TAG_TABLE.'
+  WHERE image_id IN ('.implode(',', $images).')
+    AND tag_id IN ('.implode(',', $tags).')
+;';
+  pwg_query($query);
+
+  $inserts = array();
+  foreach ($images as $image_id)
+  {
+    foreach ($tags as $tag_id)
+    {
+      array_push(
+        $inserts,
+        array(
+          'image_id' => $image_id,
+          'tag_id' => $tag_id,
+          )
+        );
+    }
+  }
+  mass_inserts(
+    IMAGE_TAG_TABLE,
+    array_keys($inserts[0]),
+    $inserts
+    );
+}
+
+function tag_id_from_tag_name($tag_name)
+{
+  global $page;
+
+  if (isset($page['tag_id_from_tag_name_cache'][$tag_name]))
+  {
+    return $page['tag_id_from_tag_name_cache'][$tag_name];
+  }
+  
+  if (function_exists('mysql_real_escape_string'))
+  {
+    $tag_name = mysql_real_escape_string($tag_name);
+  }
+  else
+  {
+    $tag_name = mysql_escape_string($tag_name);
+  }
+
+  // does the tag already exist?
+  $query = '
+SELECT id
+  FROM '.TAGS_TABLE.'
+  WHERE name = \''.$tag_name.'\'
+;';
+  $existing_tags = array_from_query($query, 'id');
+
+  if (count($existing_tags) == 0)
+  {
+    mass_inserts(
+      TAGS_TABLE,
+      array('name', 'url_name'),
+      array(
+        array(
+          'name' => $tag_name,
+          'url_name' => str2url($tag_name),
+          )
+        )
+      );
+
+    $page['tag_id_from_tag_name_cache'][$tag_name] = mysql_insert_id();
+  }
+  else
+  {
+    $page['tag_id_from_tag_name_cache'][$tag_name] = $existing_tags[0];
+  }
+
+  return $page['tag_id_from_tag_name_cache'][$tag_name];
+}
+
+function set_tags_of($tags_of)
+{
+  if (count($tags_of) > 0)
+  {
+    $query = '
+DELETE
+  FROM '.IMAGE_TAG_TABLE.'
+  WHERE image_id IN ('.implode(',', array_keys($tags_of)).')
+;';
+    pwg_query($query);
+
+    $inserts = array();
+    
+    foreach ($tags_of as $image_id => $tag_ids)
+    {
+      foreach ($tag_ids as $tag_id)
+      {
+        array_push(
+          $inserts,
+          array(
+            'image_id' => $image_id,
+            'tag_id' => $tag_id,
+            )
+          );
+      }
+    }
+
+    mass_inserts(
+      IMAGE_TAG_TABLE,
+      array_keys($inserts[0]),
+      $inserts
+      );
+  }
+}
+
+/**
  * Do maintenance on all PWG tables
  *
  * @return nono
@@ -2143,6 +2299,4 @@ function do_maintenance_all_tables()
   pwg_query($query);
 
 }
-
-
 ?>
diff --git a/admin/include/functions_metadata.php b/admin/include/functions_metadata.php
index 337019b2e..21897c2cd 100644
--- a/admin/include/functions_metadata.php
+++ b/admin/include/functions_metadata.php
@@ -50,10 +50,7 @@ function get_sync_iptc_data($file)
 
   if (isset($iptc['keywords']))
   {
-    // keywords separator is the comma, nothing else. Allowed characters in
-    // keywords : [A-Za-z0-9], "-" and "_". All other characters will be
-    // considered as separators
-    $iptc['keywords'] = preg_replace('/[^\w-]+/', ',', $iptc['keywords']);
+    // keywords separator is the comma
     $iptc['keywords'] = preg_replace('/^,+|,+$/', '', $iptc['keywords']);
   }
 
@@ -90,6 +87,7 @@ function update_metadata($files)
   }
 
   $datas = array();
+  $tags_of = array();
 
   foreach ($files as $id => $file)
   {
@@ -123,7 +121,25 @@ function update_metadata($files)
       {
         foreach (array_keys($iptc) as $key)
         {
-          $data[$key] = addslashes($iptc[$key]);
+          if ($key == 'keywords' or $key == 'tags')
+          {
+            if (!isset($tags_of[$id]))
+            {
+              $tags_of[$id] = array();
+            }
+            
+            foreach (explode(',', $iptc[$key]) as $tag_name)
+            {
+              array_push(
+                $tags_of[$id],
+                tag_id_from_tag_name($tag_name)
+                );
+            }
+          }
+          else
+          {
+            $data[$key] = addslashes($iptc[$key]);
+          }
         }
       }
     }
@@ -157,7 +173,10 @@ function update_metadata($files)
       $update_fields =
         array_merge(
           $update_fields,
-          array_keys($conf['use_iptc_mapping'])
+          array_diff(
+            array_keys($conf['use_iptc_mapping']),
+            array('tags', 'keywords')
+            )
           );
     }
 
@@ -166,8 +185,11 @@ function update_metadata($files)
         'primary' => array('id'),
         'update'  => array_unique($update_fields)
         );
+    echo '<pre>'; print_r($datas); echo '</pre>';
     mass_updates(IMAGES_TABLE, $fields, $datas);
   }
+
+  set_tags_of(tags_of);
 }
 
 /**
diff --git a/admin/picture_modify.php b/admin/picture_modify.php
index be7497a07..83bf09a23 100644
--- a/admin/picture_modify.php
+++ b/admin/picture_modify.php
@@ -100,16 +100,6 @@ if (isset($_POST['submit']) and count($page['errors']) == 0)
     }
   }
 
-  $keywords = get_keywords($_POST['keywords']);
-  if (count($keywords) > 0)
-  {
-    $data{'keywords'} = implode(',', $keywords);
-  }
-  else
-  {
-    $data{'keywords'} = '';
-  }
-
   mass_updates(
     IMAGES_TABLE,
     array(
@@ -119,6 +109,11 @@ if (isset($_POST['submit']) and count($page['errors']) == 0)
     array($data)
     );
 
+  set_tags(
+    isset($_POST['tags']) ? $_POST['tags'] : array(),
+    $_GET['image_id']
+    );
+
   array_push($page['infos'], l10n('Picture informations updated'));
 }
 // associate the element to other categories than its storage category
@@ -215,6 +210,14 @@ $row = mysql_fetch_array(pwg_query($query));
 $storage_category_id = $row['category_id'];
 $image_file = $row['file'];
 
+// tags
+$query = '
+SELECT tag_id
+  FROM '.IMAGE_TAG_TABLE.'
+  WHERE image_id = '.$_GET['image_id'].'
+;';
+$selected_tags = array_from_query($query, 'tag_id');
+
 // Navigation path
 
 $date = isset($_POST['date_creation']) && empty($page['errors'])
@@ -257,9 +260,11 @@ $template->assign_vars(
 
     'CREATION_DATE' => $date,
 
-    'KEYWORDS' =>
-      isset($_POST['keywords']) ?
-        stripslashes($_POST['keywords']) : @$row['keywords'],
+    'TAG_SELECTION' => get_html_tag_selection(
+      get_all_tags(),
+      'tags',
+      $selected_tags
+      ),
 
     'DESCRIPTION' =>
       isset($_POST['description']) ?
diff --git a/admin/site_update.php b/admin/site_update.php
index b68ce2b28..c7c31106c 100644
--- a/admin/site_update.php
+++ b/admin/site_update.php
@@ -715,6 +715,7 @@ if (isset($_POST['submit']) and preg_match('/^metadata/', $_POST['sync'])
 
   $start = get_moment();
   $datas = array();
+  $tags_of = array();
   foreach ( $files as $id=>$file )
   {
     $data = $site_reader->get_element_update_attributes($file);
@@ -723,23 +724,55 @@ if (isset($_POST['submit']) and preg_match('/^metadata/', $_POST['sync'])
       $data['date_metadata_update'] = CURRENT_DATE;
       $data['id']=$id;
       array_push($datas, $data);
+
+      foreach (array('keywords', 'tags') as $key)
+      {
+        if (isset($data[$key]))
+        {
+          if (!isset($tags_of[$id]))
+          {
+            $tags_of[$id] = array();
+          }
+        
+          foreach (explode(',', $data[$key]) as $tag_name)
+          {
+            array_push(
+              $tags_of[$id],
+              tag_id_from_tag_name($tag_name)
+              );
+          }
+        }
+      }
     }
     else
     {
       array_push($errors, array('path' => $file, 'type' => 'PWG-ERROR-NO-FS'));
     }
   }
-  $update_fields = $site_reader->get_update_attributes();
-  $update_fields = array_merge($update_fields, array('date_metadata_update'));
-  $fields =
-      array(
-        'primary' => array('id'),
-        'update'  => array_unique($update_fields)
-        );
-  //print_r($datas);
-  if (!$simulate and count($datas)>0 )
+
+  if (!$simulate)
   {
-    mass_updates(IMAGES_TABLE, $fields, $datas);
+    if (count($datas) > 0)
+    {
+      mass_updates(
+        IMAGES_TABLE,
+        // fields
+        array(
+          'primary' => array('id'),
+          'update'  => array_unique(
+            array_merge(
+              array_diff(
+                $site_reader->get_update_attributes(),
+                // keywords and tags fields are managed separately
+                array('keywords', 'tags')
+                ),
+              array('date_metadata_update'))
+            )
+          ),
+        $datas
+        );
+    }
+    set_tags_of($tags_of);
   }
 
   echo '<!-- metadata update : ';
diff --git a/admin/tags.php b/admin/tags.php
new file mode 100644
index 000000000..7ff29727c
--- /dev/null
+++ b/admin/tags.php
@@ -0,0 +1,265 @@
+<?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: 2006-03-09 23:46:28 +0100 (jeu, 09 mar 2006) $
+// | last modifier : $Author: rub $
+// | revision      : $Revision: 1072 $
+// +-----------------------------------------------------------------------+
+// | 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!");
+}
+
+include_once(PHPWG_ROOT_PATH.'admin/include/functions.php');
+check_status(ACCESS_ADMINISTRATOR);
+
+// +-----------------------------------------------------------------------+
+// |                                edit tags                              |
+// +-----------------------------------------------------------------------+
+
+if (isset($_POST['submit']))
+{
+  $query = '
+SELECT name
+  FROM '.TAGS_TABLE.'
+;';
+  $existing_names = array_from_query($query, 'name');
+  
+
+  $current_name_of = array();
+  $query = '
+SELECT id, name
+  FROM '.TAGS_TABLE.'
+  WHERE id IN ('.$_POST['edit_list'].')
+;';
+  $result = pwg_query($query);
+  while ($row = mysql_fetch_array($result))
+  {
+    $current_name_of[ $row['id'] ] = $row['name'];
+  }
+  
+  $updates = array();
+  // we must not rename tag with an already existing name
+  foreach (explode(',', $_POST['edit_list']) as $tag_id)
+  {
+    if (function_exists('mysql_real_escape_string'))
+    {
+      $tag_name = mysql_real_escape_string($_POST['tag_name-'.$tag_id]);
+    }
+    else
+    {
+      $tag_name = mysql_escape_string($_POST['tag_name-'.$tag_id]);
+    }
+
+    if ($tag_name != $current_name_of[$tag_id])
+    {
+      if (in_array($tag_name, $existing_names))
+      {
+        array_push(
+          $page['errors'],
+          sprintf(
+            l10n('Tag "%s" already exist'),
+            $tag_name
+            )
+          );
+      }
+      else if (!empty($tag_name))
+      {
+        array_push(
+          $updates,
+          array(
+            'id' => $tag_id,
+            'name' => $tag_name,
+            'url_name' => str2url($tag_name),
+            )
+          );
+      }
+    }
+  }
+  mass_updates(
+    TAGS_TABLE,
+    array(
+      'primary' => array('id'),
+      'update' => array('name', 'url_name'),
+      ),
+    $updates
+    );
+}
+
+// +-----------------------------------------------------------------------+
+// |                               delete tags                             |
+// +-----------------------------------------------------------------------+
+
+if (isset($_POST['delete']) and isset($_POST['tags']))
+{
+  $query = '
+SELECT name
+  FROM '.TAGS_TABLE.'
+  WHERE id IN ('.implode(',', $_POST['tags']).')
+;';
+  $tag_names = array_from_query($query, 'name');
+  
+  $query = '
+DELETE
+  FROM '.IMAGE_TAG_TABLE.'
+  WHERE tag_id IN ('.implode(',', $_POST['tags']).')
+;';
+  pwg_query($query);
+  
+  $query = '
+DELETE
+  FROM '.TAGS_TABLE.'
+  WHERE id IN ('.implode(',', $_POST['tags']).')
+;';
+  pwg_query($query);
+  
+  array_push(
+    $page['infos'],
+    sprintf(
+      l10n('The %d following tags were deleted : %s'),
+      count($tag_names),
+      implode(', ', $tag_names)
+      )
+    );
+}
+
+// +-----------------------------------------------------------------------+
+// |                               add a tag                               |
+// +-----------------------------------------------------------------------+
+
+if (isset($_POST['add_tag']) and !empty($_POST['add_tag']))
+{
+  if (function_exists('mysql_real_escape_string'))
+  {
+    $tag_name = mysql_real_escape_string($_POST['add_tag']);
+  }
+  else
+  {
+    $tag_name = mysql_escape_string($_POST['add_tag']);
+  }
+
+  // does the tag already exist?
+  $query = '
+SELECT id
+  FROM '.TAGS_TABLE.'
+  WHERE name = \''.$tag_name.'\'
+;';
+  $existing_tags = array_from_query($query, 'id');
+
+  if (count($existing_tags) == 0)
+  {
+    mass_inserts(
+      TAGS_TABLE,
+      array('name', 'url_name'),
+      array(
+        array(
+          'name' => $tag_name,
+          'url_name' => str2url($tag_name),
+          )
+        )
+      );
+    
+    array_push(
+      $page['infos'],
+      sprintf(
+        l10n('Tag "%s" was added'),
+        $tag_name
+        )
+      );
+  }
+  else
+  {
+    array_push(
+      $page['errors'],
+      sprintf(
+        l10n('Tag "%s" already exist'),
+        $tag_name
+        )
+      );
+  }
+}
+
+// +-----------------------------------------------------------------------+
+// |                             template init                             |
+// +-----------------------------------------------------------------------+
+
+$template->set_filenames(array('tags' => 'admin/tags.tpl'));
+
+$template->assign_vars(
+  array(
+    'F_ACTION' => PHPWG_ROOT_PATH.'admin.php?page=tags'
+    )
+  );
+
+// +-----------------------------------------------------------------------+
+// |                             form creation                             |
+// +-----------------------------------------------------------------------+
+
+$template->assign_vars(
+  array(
+    'TAG_SELECTION' => get_html_tag_selection(
+      get_all_tags(),
+      'tags'
+      ),
+    )
+  );
+
+if (isset($_POST['edit']) and isset($_POST['tags']))
+{
+  $template->assign_block_vars(
+    'edit_tags',
+    array(
+      'LIST' => implode(',', $_POST['tags']),
+      )
+    );
+
+  $query = '
+SELECT id, name
+  FROM '.TAGS_TABLE.'
+  WHERE id IN ('.implode(',', $_POST['tags']).')
+;';
+  $result = pwg_query($query);
+  while ($row = mysql_fetch_array($result))
+  {
+    $name_of[ $row['id'] ] = $row['name'];
+  }
+
+  foreach ($_POST['tags'] as $tag_id)
+  {
+    $template->assign_block_vars(
+      'edit_tags.tag',
+      array(
+        'ID' => $tag_id,
+        'NAME' => $name_of[$tag_id],
+        )
+      );
+  }
+}
+
+// +-----------------------------------------------------------------------+
+// |                           sending html code                           |
+// +-----------------------------------------------------------------------+
+
+$template->assign_var_from_handle('ADMIN_CONTENT', 'tags');
+
+?>