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 core_tag_area for managing tag areas

 *

 * @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 areas

 *

 * @package   core_tag

 * @copyright 2015 Marina Glancy

 * @license   http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later

 */

class core_tag_area {

    /**

     * Returns the list of areas indexed by itemtype and component

     *

     * @param int $tagcollid return only areas in this tag collection

     * @param bool $enabledonly return only enabled tag areas

     * @return array itemtype=>component=>tagarea object

     */

    public static function get_areas($tagcollid = null, $enabledonly = false) {

        global $DB;

        $cache = cache::make('core', 'tags');

        if (($itemtypes = $cache->get('tag_area')) === false) {

            $colls = core_tag_collection::get_collections();

            $defaultcoll = reset($colls);

            $itemtypes = array();

            $areas = $DB->get_records('tag_area', array(), 'component,itemtype');

            foreach ($areas as $area) {

                if ($colls[$area->tagcollid]->component) {

                    $area->locked = true;

                }

                $itemtypes[$area->itemtype][$area->component] = $area;

            }

            $cache->set('tag_area', $itemtypes);

        }

        if ($tagcollid || $enabledonly) {

            $rv = array();

            foreach ($itemtypes as $itemtype => $it) {

                foreach ($it as $component => $v) {

                    if (($v->tagcollid == $tagcollid || !$tagcollid) && (!$enabledonly || $v->enabled)) {

                        $rv[$itemtype][$component] = $v;

                    }

                }

            }

            return $rv;

        }

        return $itemtypes;

    }

    /**

     * Retrieves info about one tag area

     *

     * @param int $tagareaid

     * @return stdClass

     */

    public static function get_by_id($tagareaid) {

        $tagareas = self::get_areas();

        foreach ($tagareas as $itemtype => $it) {

            foreach ($it as $component => $v) {

                if ($v->id == $tagareaid) {

                    return $v;

                }

            }

        }

        return null;

    }

    /**

     * Returns the display name for this area

     *

     * @param string $component

     * @param string $itemtype

     * @return lang_string

     */

    public static function display_name($component, $itemtype) {

        $identifier = 'tagarea_' . clean_param($itemtype, PARAM_STRINGID);

        if ($component === 'core') {

            $component = 'tag';

        }

        return new lang_string($identifier, $component);

    }

    /**

     * Returns whether the tag area is enabled

     *

     * @param string $component component responsible for tagging

     * @param string $itemtype what is being tagged, for example, 'post', 'course', 'user', etc.

     * @return bool|null

     */

    public static function is_enabled($component, $itemtype) {

        global $CFG;

        if (empty($CFG->usetags)) {

            return false;

        }

        $itemtypes = self::get_areas();

        if (isset($itemtypes[$itemtype][$component])) {

            return $itemtypes[$itemtype][$component]->enabled ? true : false;

        }

        return null;

    }

    /**

     * Checks if the tag area allows items to be tagged in multiple different contexts.

     *

     * If true then it indicates that not all tag instance contexts must match the

     * context of the item they are tagging. If false then all tag instance should

     * match the context of the item they are tagging.

     *

     * Example use case for multi-context tagging:

     * A question that exists in a course category context may be used by multiple

     * child courses. The question tag area can allow tag instances to be created in

     * multiple contexts which allows the tag API to tag the question at the course

     * category context and then seperately in each of the child course contexts.

     *

     * @param string $component component responsible for tagging

     * @param string $itemtype what is being tagged, for example, 'post', 'course', 'user', etc.

     * @return bool

     */

    public static function allows_tagging_in_multiple_contexts($component, $itemtype) {

        $itemtypes = self::get_areas();

        if (isset($itemtypes[$itemtype][$component])) {

            $config = $itemtypes[$itemtype][$component];

            return isset($config->multiplecontexts) ? $config->multiplecontexts : false;

        }

        return false;

    }

    /**

     * Returns the id of the tag collection that should be used for storing tags of this itemtype

     *

     * @param string $component component responsible for tagging

     * @param string $itemtype what is being tagged, for example, 'post', 'course', 'user', etc.

     * @return int

     */

    public static function get_collection($component, $itemtype) {

        $itemtypes = self::get_areas();

        if (array_key_exists($itemtype, $itemtypes)) {

            if (!array_key_exists($component, $itemtypes[$itemtype])) {

                $component = key($itemtypes[$itemtype]);

            }

            return $itemtypes[$itemtype][$component]->tagcollid;

        }

        return core_tag_collection::get_default();

    }

    /**

     * Returns wether this tag area should display or not standard tags when user edits it.

     *

     * @param string $component component responsible for tagging

     * @param string $itemtype what is being tagged, for example, 'post', 'course', 'user', etc.

     * @return int

     */

    public static function get_showstandard($component, $itemtype) {

        $itemtypes = self::get_areas();

        if (array_key_exists($itemtype, $itemtypes)) {

            if (!array_key_exists($component, $itemtypes[$itemtype])) {

                $component = key($itemtypes[$itemtype]);

            }

            return $itemtypes[$itemtype][$component]->showstandard;

        }

        return core_tag_tag::BOTH_STANDARD_AND_NOT;

    }

    /**

     * Returns all tag areas and collections that are currently cached in DB for this component

     *

     * @param string $componentname

     * @return array first element is the list of areas and the second list of collections

     */

    protected static function get_definitions_for_component($componentname) {

        global $DB;

        list($a, $b) = core_component::normalize_component($componentname);

        $component = $b ? ($a . '_' . $b) : $a;

        $sql = 'component = :component';

        $params = array('component' => $component);

        if ($component === 'core') {

            $sql .= ' OR component LIKE :coreprefix';

            $params['coreprefix'] = 'core_%';

        }

        $fields = $DB->sql_concat_join("':'", array('itemtype', 'component'));

        $existingareas = $DB->get_records_sql(

                "SELECT $fields AS returnkey, a.* FROM {tag_area} a WHERE $sql", $params);

        $fields = $DB->sql_concat_join("':'", array('name', 'component'));

        $existingcolls = $DB->get_records_sql(

                "SELECT $fields AS returnkey, t.* FROM {tag_coll} t WHERE $sql", $params);

        return array($existingareas, $existingcolls);

    }

    /**

     * Completely delete a tag area and all instances inside it

     *

     * @param stdClass $record

     */

    protected static function delete($record) {

        global $DB;

        core_tag_tag::delete_instances($record->component, $record->itemtype);

        $DB->delete_records('tag_area',

                array('itemtype' => $record->itemtype,

                    'component' => $record->component));

        // Reset cache.

        cache::make('core', 'tags')->delete('tag_area');

    }

    /**

     * Create a new tag area

     *

     * @param stdClass $record

     */

    protected static function create($record) {

        global $DB;

        if (empty($record->tagcollid)) {

            $record->tagcollid = core_tag_collection::get_default();

        }

        $DB->insert_record('tag_area', array('component' => $record->component,

            'itemtype' => $record->itemtype,

            'tagcollid' => $record->tagcollid,

            'callback' => $record->callback,

            'callbackfile' => $record->callbackfile,

            'showstandard' => isset($record->showstandard) ? $record->showstandard : core_tag_tag::BOTH_STANDARD_AND_NOT,

            'multiplecontexts' => isset($record->multiplecontexts) ? $record->multiplecontexts : 0));

        // Reset cache.

        cache::make('core', 'tags')->delete('tag_area');

    }

    /**

     * Update the tag area

     *

     * @param stdClass $existing current record from DB table tag_area

     * @param array|stdClass $data fields that need updating

     */

    public static function update($existing, $data) {

        global $DB;

        $data = array_intersect_key((array)$data,

                array('enabled' => 1, 'tagcollid' => 1,

                    'callback' => 1, 'callbackfile' => 1, 'showstandard' => 1,

                    'multiplecontexts' => 1));

        foreach ($data as $key => $value) {

            if ($existing->$key == $value) {

                unset($data[$key]);

            }

        }

        if (!$data) {

            return;

        }

        if (!empty($data['tagcollid'])) {

            self::move_tags($existing->component, $existing->itemtype, $data['tagcollid']);

        }

        $data['id'] = $existing->id;

        $DB->update_record('tag_area', $data);

        // Reset cache.

        cache::make('core', 'tags')->delete('tag_area');

    }

    /**

     * Update the database to contain a list of tagged areas for a component.

     * The list of tagged areas is read from [plugindir]/db/tag.php

     *

     * @param string $componentname - The frankenstyle component name.

     */

    public static function reset_definitions_for_component($componentname) {

        global $DB;

        $dir = core_component::get_component_directory($componentname);

        $file = $dir . '/db/tag.php';

        $tagareas = null;

        if (file_exists($file)) {

            require_once($file);

        }

        list($a, $b) = core_component::normalize_component($componentname);

        $component = $b ? ($a . '_' . $b) : $a;

        list($existingareas, $existingcolls) = self::get_definitions_for_component($componentname);

        $itemtypes = array();

        $collections = array();

        $needcleanup = false;

        if ($tagareas) {

            foreach ($tagareas as $tagarea) {

                $record = (object)$tagarea;

                if ($component !== 'core' || empty($record->component)) {

                    if (isset($record->component) && $record->component !== $component) {

                        debugging("Item type {$record->itemtype} has illegal component {$record->component}", DEBUG_DEVELOPER);

                    }

                    $record->component = $component;

                }

                unset($record->tagcollid);

                if (!empty($record->collection)) {

                    // Create collection if it does not exist, or update 'searchable' and/or 'customurl' if needed.

                    $key = $record->collection . ':' . $record->component;

                    $collectiondata = array_intersect_key((array)$record,

                            array('component' => 1, 'searchable' => 1, 'customurl' => 1));

                    $collectiondata['name'] = $record->collection;

                    if (!array_key_exists($key, $existingcolls)) {

                        $existingcolls[$key] = core_tag_collection::create($collectiondata);

                    } else {

                        core_tag_collection::update($existingcolls[$key], $collectiondata);

                    }

                    $record->tagcollid = $existingcolls[$key]->id;

                    $collections[$key] = $existingcolls[$key];

                    unset($record->collection);

                }

                unset($record->searchable);

                unset($record->customurl);

                if (!isset($record->callback)) {

                    $record->callback = null;

                }

                if (!isset($record->callbackfile)) {

                    $record->callbackfile = null;

                }

                if (!isset($record->multiplecontexts)) {

                    $record->multiplecontexts = false;

                }

                $itemtypes[$record->itemtype . ':' . $record->component] = $record;

            }

        }

        $todeletearea = array_diff_key($existingareas, $itemtypes);

        $todeletecoll = array_diff_key($existingcolls, $collections);

        // Delete tag areas that are no longer needed.

        foreach ($todeletearea as $key => $record) {

            self::delete($record);

        }

        // Update tag areas if changed.

        $toupdatearea = array_intersect_key($existingareas, $itemtypes);

        foreach ($toupdatearea as $key => $tagarea) {

            if (!isset($itemtypes[$key]->tagcollid)) {

                foreach ($todeletecoll as $tagcoll) {

                    if ($tagcoll->id == $tagarea->tagcollid) {

                        $itemtypes[$key]->tagcollid = core_tag_collection::get_default();

                    }

                }

            }

            unset($itemtypes[$key]->showstandard); // Do not override value that was already changed by admin with the default.

            self::update($tagarea, $itemtypes[$key]);

        }

        // Create new tag areas.

        $toaddarea = array_diff_key($itemtypes, $existingareas);

        foreach ($toaddarea as $record) {

            self::create($record);

        }

        // Delete tag collections that are no longer needed.

        foreach ($todeletecoll as $key => $tagcoll) {

            core_tag_collection::delete($tagcoll);

        }

    }

    /**

     * Deletes all tag areas, collections and instances associated with the plugin.

     *

     * @param string $pluginname

     */

    public static function uninstall($pluginname) {

        global $DB;

        list($a, $b) = core_component::normalize_component($pluginname);

        if (empty($b) || $a === 'core') {

            throw new coding_exception('Core component can not be uninstalled');

        }

        $component = $a . '_' . $b;

        core_tag_tag::delete_instances($component);

        $DB->delete_records('tag_area', array('component' => $component));

        $DB->delete_records('tag_coll', array('component' => $component));

        cache::make('core', 'tags')->delete_many(array('tag_area', 'tag_coll'));

    }

    /**

     * Moves existing tags associated with an item type to another tag collection

     *

     * @param string $component

     * @param string $itemtype

     * @param int $tagcollid

     */

    public static function move_tags($component, $itemtype, $tagcollid) {

        global $DB;

        $params = array('itemtype1' => $itemtype, 'component1' => $component,

            'itemtype2' => $itemtype, 'component2' => $component,

            'tagcollid1' => $tagcollid, 'tagcollid2' => $tagcollid);

        // Find all collections that need to be cleaned later.

        $sql = "SELECT DISTINCT t.tagcollid " .

            "FROM {tag_instance} ti " .

            "JOIN {tag} t ON t.id = ti.tagid AND t.tagcollid <> :tagcollid1 " .

            "WHERE ti.itemtype = :itemtype2 AND ti.component = :component2 ";

        $cleanupcollections = $DB->get_fieldset_sql($sql, $params);

        // Find all tags that are related to the tags being moved and make sure they are present in the target tagcoll.

        // This query is a little complicated because Oracle does not allow to run SELECT DISTINCT on CLOB fields.

        $sql = "SELECT name, rawname, description, descriptionformat, userid, isstandard, flag, timemodified ".

                "FROM {tag} WHERE id IN ".

                "(SELECT r.id ".

                "FROM {tag_instance} ti ". // Instances that need moving.

                "JOIN {tag} t ON t.id = ti.tagid AND t.tagcollid <> :tagcollid1 ". // Tags that need moving.

                "JOIN {tag_instance} tr ON tr.itemtype = 'tag' and tr.component = 'core' AND tr.itemid = t.id ".

                "JOIN {tag} r ON r.id = tr.tagid ". // Tags related to the tags that need moving.

                "LEFT JOIN {tag} re ON re.name = r.name AND re.tagcollid = :tagcollid2 ". // Existing tags in the target tagcoll with the same name as related tags.

                "WHERE ti.itemtype = :itemtype2 AND ti.component = :component2 ".

                "    AND re.id IS NULL)"; // We need related tags that ARE NOT present in the target tagcoll.

        $result = $DB->get_records_sql($sql, $params);

        foreach ($result as $tag) {

            $tag->tagcollid = $tagcollid;

            $tag->id = $DB->insert_record('tag', $tag);

            \core\event\tag_created::create_from_tag($tag);

        }

        // Find all tags that need moving and have related tags, remember their related tags.

        $sql = "SELECT t.name AS tagname, r.rawname AS relatedtag ".

                "FROM {tag_instance} ti ". // Instances that need moving.

                "JOIN {tag} t ON t.id = ti.tagid AND t.tagcollid <> :tagcollid1 ". // Tags that need moving.

                "JOIN {tag_instance} tr ON t.id = tr.tagid AND tr.itemtype = 'tag' and tr.component = 'core' ".

                "JOIN {tag} r ON r.id = tr.itemid ". // Tags related to the tags that need moving.

                "WHERE ti.itemtype = :itemtype2 AND ti.component = :component2 ".

                "ORDER BY t.id, tr.ordering ";

        $relatedtags = array();

        $result = $DB->get_recordset_sql($sql, $params);

        foreach ($result as $record) {

            $relatedtags[$record->tagname][] = $record->relatedtag;

        }

        $result->close();

        // Find all tags that are used for this itemtype/component and are not present in the target tag collection.

        // This query is a little complicated because Oracle does not allow to run SELECT DISTINCT on CLOB fields.

        $sql = "SELECT id, name, rawname, description, descriptionformat, userid, isstandard, flag, timemodified

                FROM {tag} WHERE id IN

                (SELECT t.id

                FROM {tag_instance} ti

                JOIN {tag} t ON t.id = ti.tagid AND t.tagcollid <> :tagcollid1

                LEFT JOIN {tag} tt ON tt.name = t.name AND tt.tagcollid = :tagcollid2

                WHERE ti.itemtype = :itemtype2 AND ti.component = :component2

                    AND tt.id IS NULL)";

        $movedtags = array(); // Keep track of moved tags so we don't hit DB index violation.

        $result = $DB->get_records_sql($sql, $params);

        foreach ($result as $tag) {

            $originaltagid = $tag->id;

            if (array_key_exists($tag->name, $movedtags)) {

                // Case of corrupted data when the same tag was in several collections.

                $tag->id = $movedtags[$tag->name];

            } else {

                // Copy the tag into the new collection.

                unset($tag->id);

                $tag->tagcollid = $tagcollid;

                $tag->id = $DB->insert_record('tag', $tag);

                \core\event\tag_created::create_from_tag($tag);

                $movedtags[$tag->name] = $tag->id;

            }

            $DB->execute("UPDATE {tag_instance} SET tagid = ? WHERE tagid = ? AND itemtype = ? AND component = ?",

                    array($tag->id, $originaltagid, $itemtype, $component));

        }

        // Find all tags that are used for this itemtype/component and are already present in the target tag collection.

        $sql = "SELECT DISTINCT t.id, tt.id AS targettagid

                FROM {tag_instance} ti

                JOIN {tag} t ON t.id = ti.tagid AND t.tagcollid <> :tagcollid1

                JOIN {tag} tt ON tt.name = t.name AND tt.tagcollid = :tagcollid2

                WHERE ti.itemtype = :itemtype2 AND ti.component = :component2";

        $result = $DB->get_records_sql($sql, $params);

        foreach ($result as $tag) {

            $DB->execute("UPDATE {tag_instance} SET tagid = ? WHERE tagid = ? AND itemtype = ? AND component = ?",

                    array($tag->targettagid, $tag->id, $itemtype, $component));

        }

        // Add related tags to the moved tags.

        if ($relatedtags) {

            $tags = core_tag_tag::get_by_name_bulk($tagcollid, array_keys($relatedtags));

            foreach ($tags as $tag) {

                $tag->add_related_tags($relatedtags[$tag->name]);

            }

        }

        if ($cleanupcollections) {

            core_tag_collection::cleanup_unused_tags($cleanupcollections);

        }

        // Reset caches.

        cache::make('core', 'tags')->delete('tag_area');

    }

}