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/>.

/**

 * @package    moodlecore

 * @subpackage backup-dbops

 * @copyright  2010 onwards Eloy Lafuente (stronk7) {@link http://stronk7.com}

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

 */

/**

 * Non instantiable helper class providing DB support to the questions backup stuff

 *

 * This class contains various static methods available for all the DB operations

 * performed by questions stuff

 *

 * TODO: Finish phpdocs

 */

abstract class backup_question_dbops extends backup_dbops {

    /**

     * Calculates all the question_categories to be included

     * in backup, based in a given context (course/module) and

     * the already annotated questions present in backup_ids_temp

     */

    public static function calculate_question_categories($backupid, $contextid) {

        global $DB;

        // First step, get all the categories for the given context (course/module)

        // i.e. the whole context questions bank

        $contextcategories = $DB->get_records_menu('question_categories', ['contextid' => $contextid], '', 'id, parent');

        // Now, based in the annotated question bank entries, get all the categories they

        // belong to.

        $questioncategories = $DB->get_records_sql_menu(

            "SELECT DISTINCT qc2.id, qc2.parent

               FROM {question_categories} qc2

                    JOIN {question_bank_entries} qbe ON qbe.questioncategoryid = qc2.id

                    JOIN {backup_ids_temp} bi ON bi.itemid = qbe.id

              WHERE bi.backupid = ?

                    AND bi.itemname = 'question_bank_entry'

                    AND qc2.contextid != ?",

            [$backupid, $contextid]

        );

        // These are all the question categories we want to include in the backup.

        $categories = $contextcategories + $questioncategories;

        // If we're not already including the parents of a category, add them in.

        foreach ($categories as $parentid) {

            if (!array_key_exists($parentid, $categories)) {

                $categories += self::get_parent_categories($parentid);

            }

        }

        // Insert annotations of the found categories.

        foreach (array_keys($categories) as $categoryid) {

            backup_structure_dbops::insert_backup_ids_record($backupid, 'question_category', $categoryid);

        }

        // For these categories, we want to include all questions.

        foreach (array_keys($contextcategories) as $categoryid) {

            backup_structure_dbops::insert_backup_ids_record($backupid, 'question_category_complete', $categoryid);

        }

        // For these categories, we only want to include the questions that have been annotated.

        // Exclude those where we're already including all questions.

        $partialcategories = array_diff(

            array_keys($questioncategories),

            array_keys($contextcategories),

        );

        foreach ($partialcategories as $categoryid) {

            backup_structure_dbops::insert_backup_ids_record($backupid, 'question_category_partial', $categoryid);

        }

    }

    /**

     * Recursively find the parents and ancestors of the given category

     *

     * @param int $categoryid The category we want to find parents for.

     * @return array id => parentid for each category

     */

    protected static function get_parent_categories(int $categoryid): array {

        global $DB;

        $parentcategories = [];

        $parentid = $DB->get_field('question_categories', 'parent', ['id' => $categoryid]);

        $parentcategories[$categoryid] = $parentid;

        // If this is not a top category, keep going.

        if ($parentid > 0) {

            array_merge($parentcategories, self::get_parent_categories($parentid));

        }

        return $parentcategories;

    }

    /**

     * Delete all the annotated questions present in backup_ids_temp

     */

    public static function delete_temp_questions($backupid) {

        global $DB;

        $DB->delete_records('backup_ids_temp', array('backupid' => $backupid, 'itemname' => 'question'));

    }

}