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<?php
// This file is part of Moodle - http://moodle.org/
//
// Moodle 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, either version 3 of the License, or
// (at your option) any later version.
//
// Moodle 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 Moodle. If not, see <http://www.gnu.org/licenses/>.
/**
* Class to manage tag collections
*
* @package core_tag
* @copyright 2015 Marina Glancy
* @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
*/
defined('MOODLE_INTERNAL') || die();
/**
* Class to manage tag collections
*
* @package core_tag
* @copyright 2015 Marina Glancy
* @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
*/
class core_tag_collection {
/** @var string used for function cloud_sort() */
public static $cloudsortfield = 'name';
/**
* Returns the list of tag collections defined in the system.
*
* @param bool $onlysearchable only return collections that can be searched.
* @return array array of objects where each object has properties: id, name, isdefault, itemtypes, sortorder
*/
public static function get_collections($onlysearchable = false) {
global $DB;
$cache = cache::make('core', 'tags');
if (($tagcolls = $cache->get('tag_coll')) === false) {
// Retrieve records from DB and create a default one if it is not present.
$tagcolls = $DB->get_records('tag_coll', null, 'isdefault DESC, sortorder, id');
if (empty($tagcolls)) {
// When this method is called for the first time it automatically creates the default tag collection.
$DB->insert_record('tag_coll', array('isdefault' => 1, 'sortorder' => 0));
$tagcolls = $DB->get_records('tag_coll');
} else {
// Make sure sortorder is correct.
$idx = 0;
foreach ($tagcolls as $id => $tagcoll) {
if ($tagcoll->sortorder != $idx) {
$DB->update_record('tag_coll', array('sortorder' => $idx, 'id' => $id));
$tagcolls[$id]->sortorder = $idx;
}
$idx++;
}
}
$cache->set('tag_coll', $tagcolls);
}
if ($onlysearchable) {
$rv = array();
foreach ($tagcolls as $id => $tagcoll) {
if ($tagcoll->searchable) {
$rv[$id] = $tagcoll;
}
}
return $rv;
}
return $tagcolls;
}
/**
* Returns the tag collection object
*
* @param int $tagcollid
* @return stdClass
*/
public static function get_by_id($tagcollid) {
$tagcolls = self::get_collections();
if (array_key_exists($tagcollid, $tagcolls)) {
return $tagcolls[$tagcollid];
}
return null;
}
/**
* Returns the list of existing tag collections as id=>name
*
* @param bool $unlockedonly
* @param bool $onlysearchable
* @param string $selectalllabel
* @return array
*/
public static function get_collections_menu($unlockedonly = false, $onlysearchable = false,
$selectalllabel = null) {
$tagcolls = self::get_collections($onlysearchable);
$options = array();
foreach ($tagcolls as $id => $tagcoll) {
if (!$unlockedonly || empty($tagcoll->component)) {
$options[$id] = self::display_name($tagcoll);
}
}
if (count($options) > 1 && $selectalllabel) {
$options = array(0 => $selectalllabel) + $options;
}
return $options;
}
/**
* Returns id of the default tag collection
*
* @return int
*/
public static function get_default() {
$collections = self::get_collections();
$keys = array_keys($collections);
return $keys[0];
}
/**
* Returns formatted name of the tag collection
*
* @param stdClass $record record from DB table tag_coll
* @return string
*/
public static function display_name($record) {
$syscontext = context_system::instance();
if (!empty($record->component)) {
$identifier = 'tagcollection_' .
clean_param($record->name, PARAM_STRINGID);
$component = $record->component;
if ($component === 'core') {
$component = 'tag';
}
return get_string($identifier, $component);
}
if (!empty($record->name)) {
return format_string($record->name, true, array('context' => $syscontext));
} else if ($record->isdefault) {
return get_string('defautltagcoll', 'tag');
} else {
return $record->id;
}
}
/**
* Returns all tag areas in the given tag collection
*
* @param int $tagcollid
* @return array
*/
public static function get_areas($tagcollid) {
$allitemtypes = core_tag_area::get_areas($tagcollid, true);
$itemtypes = array();
foreach ($allitemtypes as $itemtype => $it) {
foreach ($it as $component => $v) {
$itemtypes[$v->id] = $v;
}
}
return $itemtypes;
}
/**
* Returns the list of names of areas (enabled only) that are in this collection.
*
* @param int $tagcollid
* @return array
*/
public static function get_areas_names($tagcollid, $enabledonly = true) {
$allitemtypes = core_tag_area::get_areas($tagcollid, $enabledonly);
$itemtypes = array();
foreach ($allitemtypes as $itemtype => $it) {
foreach ($it as $component => $v) {
$itemtypes[$v->id] = core_tag_area::display_name($component, $itemtype);
}
}
return $itemtypes;
}
/**
* Creates a new tag collection
*
* @param stdClass $data data from form core_tag_collection_form
* @return int|false id of created tag collection or false if failed
*/
public static function create($data) {
global $DB;
$data = (object)$data;
$tagcolls = self::get_collections();
$tagcoll = (object)array(
'name' => $data->name,
'isdefault' => 0,
'component' => !empty($data->component) ? $data->component : null,
'sortorder' => count($tagcolls),
'searchable' => isset($data->searchable) ? (int)(bool)$data->searchable : 1,
'customurl' => !empty($data->customurl) ? $data->customurl : null,
);
$tagcoll->id = $DB->insert_record('tag_coll', $tagcoll);
// Reset cache.
cache::make('core', 'tags')->delete('tag_coll');
\core\event\tag_collection_created::create_from_record($tagcoll)->trigger();
return $tagcoll;
}
/**
* Updates the tag collection information
*
* @param stdClass $tagcoll existing record in DB table tag_coll
* @param stdClass $data data to update
* @return bool wether the record was updated
*/
public static function update($tagcoll, $data) {
global $DB;
$defaulttagcollid = self::get_default();
$allowedfields = array('name', 'searchable', 'customurl');
if ($tagcoll->id == $defaulttagcollid) {
$allowedfields = array('name');
}
$updatedata = array();
$data = (array)$data;
foreach ($allowedfields as $key) {
if (array_key_exists($key, $data) && $data[$key] !== $tagcoll->$key) {
$updatedata[$key] = $data[$key];
}
}
if (!$updatedata) {
// Nothing to update.
return false;
}
if (isset($updatedata['searchable'])) {
$updatedata['searchable'] = (int)(bool)$updatedata['searchable'];
}
foreach ($updatedata as $key => $value) {
$tagcoll->$key = $value;
}
$updatedata['id'] = $tagcoll->id;
$DB->update_record('tag_coll', $updatedata);
// Reset cache.
cache::make('core', 'tags')->delete('tag_coll');
\core\event\tag_collection_updated::create_from_record($tagcoll)->trigger();
return true;
}
/**
* Deletes a custom tag collection
*
* @param stdClass $tagcoll existing record in DB table tag_coll
* @return bool wether the tag collection was deleted
*/
public static function delete($tagcoll) {
global $DB, $CFG;
$defaulttagcollid = self::get_default();
if ($tagcoll->id == $defaulttagcollid) {
return false;
}
// Move all tags from this tag collection to the default one.
$allitemtypes = core_tag_area::get_areas($tagcoll->id);
foreach ($allitemtypes as $it) {
foreach ($it as $v) {
core_tag_area::update($v, array('tagcollid' => $defaulttagcollid));
}
}
// Delete tags from this tag_coll.
core_tag_tag::delete_tags($DB->get_fieldset_select('tag', 'id', 'tagcollid = ?', array($tagcoll->id)));
// Delete the tag collection.
$DB->delete_records('tag_coll', array('id' => $tagcoll->id));
// Reset cache.
cache::make('core', 'tags')->delete('tag_coll');
\core\event\tag_collection_deleted::create_from_record($tagcoll)->trigger();
return true;
}
/**
* Moves the tag collection in the list one position up or down
*
* @param stdClass $tagcoll existing record in DB table tag_coll
* @param int $direction move direction: +1 or -1
* @return bool
*/
public static function change_sortorder($tagcoll, $direction) {
global $DB;
if ($direction != -1 && $direction != 1) {
throw new coding_exception('Second argument in tag_coll_change_sortorder() can be only 1 or -1');
}
$tagcolls = self::get_collections();
$keys = array_keys($tagcolls);
$idx = array_search($tagcoll->id, $keys);
if ($idx === false || $idx == 0 || $idx + $direction < 1 || $idx + $direction >= count($tagcolls)) {
return false;
}
$otherid = $keys[$idx + $direction];
$DB->update_record('tag_coll', array('id' => $tagcoll->id, 'sortorder' => $idx + $direction));
$DB->update_record('tag_coll', array('id' => $otherid, 'sortorder' => $idx));
// Reset cache.
cache::make('core', 'tags')->delete('tag_coll');
return true;
}
/**
* Permanently deletes all non-standard tags that no longer have any instances pointing to them
*
* @param array $collections optional list of tag collections ids to cleanup
*/
public static function cleanup_unused_tags($collections = null) {
global $DB, $CFG;
$params = array();
$sql = "SELECT tg.id FROM {tag} tg LEFT OUTER JOIN {tag_instance} ti ON ti.tagid = tg.id
WHERE ti.id IS NULL AND tg.isstandard = 0";
if ($collections) {
list($sqlcoll, $params) = $DB->get_in_or_equal($collections, SQL_PARAMS_NAMED);
$sql .= " AND tg.tagcollid " . $sqlcoll;
}
if ($unusedtags = $DB->get_fieldset_sql($sql, $params)) {
core_tag_tag::delete_tags($unusedtags);
}
}
/**
* Returns the list of tags with number of items tagged
*
* @param int $tagcollid
* @param null|bool $isstandard return only standard tags
* @param int $limit maximum number of tags to retrieve, tags are sorted by the instance count
* descending here regardless of $sort parameter
* @param string $sort sort order for display, default 'name' - tags will be sorted after they are retrieved
* @param string $search search string
* @param int $fromctx context id where this tag cloud is displayed
* @param int $ctx only retrieve tag instances in this context
* @param int $rec retrieve tag instances in the $ctx context and it's children (default 1)
* @return \core_tag\output\tagcloud
*/
public static function get_tag_cloud($tagcollid, $isstandard = false, $limit = 150, $sort = 'name',
$search = '', $fromctx = 0, $ctx = 0, $rec = 1) {
global $DB;
$fromclause = 'FROM {tag_instance} ti JOIN {tag} tg ON tg.id = ti.tagid';
$whereclause = 'WHERE ti.itemtype <> \'tag\'';
list($sql, $params) = $DB->get_in_or_equal($tagcollid ? array($tagcollid) :
array_keys(self::get_collections(true)));
$whereclause .= ' AND tg.tagcollid ' . $sql;
if ($isstandard) {
$whereclause .= ' AND tg.isstandard = 1';
}
$context = $ctx ? context::instance_by_id($ctx) : context_system::instance();
if ($rec && $context->contextlevel != CONTEXT_SYSTEM) {
$fromclause .= ' JOIN {context} ctx ON ctx.id = ti.contextid ';
$whereclause .= ' AND ctx.path LIKE ?';
$params[] = $context->path . '%';
} else if (!$rec) {
$whereclause .= ' AND ti.contextid = ?';
$params[] = $context->id;
}
if (strval($search) !== '') {
$whereclause .= ' AND tg.name LIKE ?';
$params[] = '%' . core_text::strtolower($search) . '%';
}
$tagsincloud = $DB->get_records_sql(
"SELECT tg.id, tg.rawname, tg.name, tg.isstandard, COUNT(ti.id) AS count, tg.flag, tg.tagcollid
$fromclause
$whereclause
GROUP BY tg.id, tg.rawname, tg.name, tg.flag, tg.isstandard, tg.tagcollid
ORDER BY count DESC, tg.name ASC",
$params, 0, $limit);
$tagscount = count($tagsincloud);
if ($tagscount == $limit) {
$tagscount = $DB->get_field_sql("SELECT COUNT(DISTINCT tg.id) $fromclause $whereclause", $params);
}
self::$cloudsortfield = $sort;
usort($tagsincloud, "self::cloud_sort");
return new core_tag\output\tagcloud($tagsincloud, $tagscount, $fromctx, $ctx, $rec);
}
/**
* This function is used to sort the tags in the cloud.
*
* @param string $a Tag name to compare against $b
* @param string $b Tag name to compare against $a
* @return int The result of the comparison/validation 1, 0 or -1
*/
public static function cloud_sort($a, $b) {
$tagsort = self::$cloudsortfield ?: 'name';
if (is_numeric($a->$tagsort)) {
return ($a->$tagsort == $b->$tagsort) ? 0 : ($a->$tagsort > $b->$tagsort) ? 1 : -1;
} else if (is_string($a->$tagsort)) {
return strcmp($a->$tagsort, $b->$tagsort);
} else {
return 0;
}
}
}