Proyectos de Subversion Moodle

<?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::class . "::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;

        }

    }

}