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Diffstat (limited to 'include/functions_tag.inc.php')
| -rw-r--r-- | include/functions_tag.inc.php | 218 |
1 files changed, 218 insertions, 0 deletions
diff --git a/include/functions_tag.inc.php b/include/functions_tag.inc.php new file mode 100644 index 000000000..5dd4884f4 --- /dev/null +++ b/include/functions_tag.inc.php @@ -0,0 +1,218 @@ +<?php +// +-----------------------------------------------------------------------+ +// | PhpWebGallery - a PHP based picture gallery | +// | Copyright (C) 2002-2003 Pierrick LE GALL - pierrick@phpwebgallery.net | +// | Copyright (C) 2003-2006 PhpWebGallery Team - http://phpwebgallery.net | +// +-----------------------------------------------------------------------+ +// | branch : BSF (Best So Far) +// | file : $RCSfile$ +// | last update : $Date: 2006-03-16 23:58:16 +0100 (jeu, 16 mar 2006) $ +// | last modifier : $Author: rub $ +// | revision : $Revision: 1085 $ +// | revision : $Revision: 1085 $ +// +-----------------------------------------------------------------------+ +// | 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. | +// +-----------------------------------------------------------------------+ + + +/** + * Tags available. Each return tag is represented as an array with its id, + * its name, its weight (count), its url name. Tags are not sorted. + * + * The returned list can be a subset of all existing tags due to + * permissions, only if a list of forbidden categories is provided + * + * @param array forbidden categories + * @return array + */ +function get_available_tags($forbidden_categories = null) +{ + // we can find top fatter tags among reachable images + $tags_query = ' +SELECT tag_id, name, url_name, count(*) counter + FROM '.IMAGE_TAG_TABLE.' + INNER JOIN '.TAGS_TABLE.' ON tag_id = id'; + + if (!is_null($forbidden_categories)) + { + // first we need all reachable image ids + $images_query = ' +SELECT DISTINCT image_id + FROM '.IMAGE_CATEGORY_TABLE.' + WHERE category_id NOT IN ('.implode(',', $forbidden_categories).') +;'; + $image_ids = array_from_query($images_query, 'image_id'); + + $tags_query.= ' + WHERE image_id IN ('. + wordwrap( + implode(', ', $image_ids), + 80, + "\n" + ).')'; + } + + $tags_query.= ' + GROUP BY tag_id +;'; + + $result = pwg_query($tags_query); + + $tags = array(); + + while ($row = mysql_fetch_array($result)) + { + array_push($tags, $row); + } + + return $tags; +} + +/** + * All tags, even tags associated to no image. + * + * @return array + */ +function get_all_tags() +{ + $query = ' +SELECT id AS tag_id, name, url_name + FROM '.TAGS_TABLE.' + ORDER BY name +;'; + $result = pwg_query($query); + + $tags = array(); + + while ($row = mysql_fetch_array($result)) + { + array_push($tags, $row); + } + + return $tags; +} + +/** + * Giving a set of tags with a counter for each one, calculate the display + * level of each tag. + * + * The level of each tag depends on the average count of tags. This + * calcylation method avoid having very different levels for tags having + * nearly the same count when set are small. + * + * @param array tags + * @return array + */ +function add_level_to_tags($tags) +{ + global $conf; + + if (count($tags) == 0) + { + return $tags; + } + + $total_count = 0; + + foreach ($tags as $tag) + { + $total_count+= $tag['counter']; + } + + // average count of available tags will determine the level of each tag + $tag_average_count = $total_count / count($tags); + + // tag levels threshold calculation: a tag with an average rate must have + // the middle level. + for ($i = 1; $i < $conf['tags_levels']; $i++) + { + $threshold_of_level[$i] = + 2 * $i * $tag_average_count / $conf['tags_levels']; + } + + // display sorted tags + foreach (array_keys($tags) as $k) + { + $tags[$k]['level'] = 1; + + // based on threshold, determine current tag level + for ($i = $conf['tags_levels'] - 1; $i >= 1; $i--) + { + if ($tags[$k]['counter'] > $threshold_of_level[$i]) + { + $tags[$k]['level'] = $i + 1; + break; + } + } + } + + return $tags; +} + +/** + * return the list of image ids corresponding to given tags. AND & OR mode + * supported. + * + * @param array tag ids + * @param string mode + * @return array + */ +function get_image_ids_for_tags($tag_ids, $mode = 'AND') +{ + switch ($mode) + { + case 'AND': + { + // strategy is to list images associated to each tag + $tag_images = array(); + + foreach ($tag_ids as $tag_id) + { + $query = ' +SELECT image_id + FROM '.IMAGE_TAG_TABLE.' + WHERE tag_id = '.$tag_id.' +;'; + $tag_images[$tag_id] = array_from_query($query, 'image_id'); + } + + // then we calculate the intersection, the images that are associated to + // every tags + $items = array_shift($tag_images); + foreach ($tag_images as $images) + { + $items = array_intersect($items, $images); + } + + return array_unique($items); + break; + } + case 'OR': + { + $query = ' +SELECT DISTINCT image_id + FROM '.IMAGE_TAG_TABLE.' + WHERE tag_id IN ('.implode(',', $tag_ids).') +;'; + return array_from_query($query, 'image_id'); + break; + } + default: + { + die('get_image_ids_for_tags: unknown mode, only AND & OR are supported'); + } + } +} +?>
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