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/>.

/**

 * Privacy Subsystem implementation for mod_choice.

 *

 * @package    mod_choice

 * @category   privacy

 * @copyright  2018 Jun Pataleta

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

 */

namespace mod_choice\privacy;

use core_privacy\local\metadata\collection;

use core_privacy\local\request\approved_contextlist;

use core_privacy\local\request\approved_userlist;

use core_privacy\local\request\contextlist;

use core_privacy\local\request\deletion_criteria;

use core_privacy\local\request\helper;

use core_privacy\local\request\userlist;

use core_privacy\local\request\writer;

defined('MOODLE_INTERNAL') || die();

/**

 * Implementation of the privacy subsystem plugin provider for the choice activity module.

 *

 * @copyright  2018 Jun Pataleta

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

 */

class provider implements

        // This plugin stores personal data.

        \core_privacy\local\metadata\provider,

        // This plugin is a core_user_data_provider.

        \core_privacy\local\request\plugin\provider,

        // This plugin is capable of determining which users have data within it.

        \core_privacy\local\request\core_userlist_provider {

    /**

     * Return the fields which contain personal data.

     *

     * @param collection $items a reference to the collection to use to store the metadata.

     * @return collection the updated collection of metadata items.

     */

    public static function get_metadata(collection $items): collection {

        $items->add_database_table(

            'choice_answers',

            [

                'choiceid' => 'privacy:metadata:choice_answers:choiceid',

                'optionid' => 'privacy:metadata:choice_answers:optionid',

                'userid' => 'privacy:metadata:choice_answers:userid',

                'timemodified' => 'privacy:metadata:choice_answers:timemodified',

            ],

            'privacy:metadata:choice_answers'

        );

        return $items;

    }

    /**

     * Get the list of contexts that contain user information for the specified user.

     *

     * @param int $userid the userid.

     * @return contextlist the list of contexts containing user info for the user.

     */

    public static function get_contexts_for_userid(int $userid): contextlist {

        // Fetch all choice answers.

        $sql = "SELECT c.id

                  FROM {context} c

            INNER JOIN {course_modules} cm ON cm.id = c.instanceid AND c.contextlevel = :contextlevel

            INNER JOIN {modules} m ON m.id = cm.module AND m.name = :modname

            INNER JOIN {choice} ch ON ch.id = cm.instance

            INNER JOIN {choice_options} co ON co.choiceid = ch.id

            INNER JOIN {choice_answers} ca ON ca.optionid = co.id AND ca.choiceid = ch.id

                 WHERE ca.userid = :userid";

        $params = [

            'modname'       => 'choice',

            'contextlevel'  => CONTEXT_MODULE,

            'userid'        => $userid,

        ];

        $contextlist = new contextlist();

        $contextlist->add_from_sql($sql, $params);

        return $contextlist;

    }

    /**

     * Get the list of users who have data within a context.

     *

     * @param   userlist    $userlist   The userlist containing the list of users who have data in this context/plugin combination.

     */

    public static function get_users_in_context(userlist $userlist) {

        $context = $userlist->get_context();

        if (!$context instanceof \context_module) {

            return;

        }

        // Fetch all choice answers.

        $sql = "SELECT ca.userid

                  FROM {course_modules} cm

                  JOIN {modules} m ON m.id = cm.module AND m.name = :modname

                  JOIN {choice} ch ON ch.id = cm.instance

                  JOIN {choice_options} co ON co.choiceid = ch.id

                  JOIN {choice_answers} ca ON ca.optionid = co.id AND ca.choiceid = ch.id

                 WHERE cm.id = :cmid";

        $params = [

            'cmid'      => $context->instanceid,

            'modname'   => 'choice',

        ];

        $userlist->add_from_sql('userid', $sql, $params);

    }

    /**

     * Export personal data for the given approved_contextlist. User and context information is contained within the contextlist.

     *

     * @param approved_contextlist $contextlist a list of contexts approved for export.

     */

    public static function export_user_data(approved_contextlist $contextlist) {

        global $DB;

        if (empty($contextlist->count())) {

            return;

        }

        $user = $contextlist->get_user();

        list($contextsql, $contextparams) = $DB->get_in_or_equal($contextlist->get_contextids(), SQL_PARAMS_NAMED);

        $sql = "SELECT cm.id AS cmid,

                       co.text as answer,

                       ca.timemodified

                  FROM {context} c

            INNER JOIN {course_modules} cm ON cm.id = c.instanceid AND c.contextlevel = :contextlevel

            INNER JOIN {modules} m ON m.id = cm.module AND m.name = :modname

            INNER JOIN {choice} ch ON ch.id = cm.instance

            INNER JOIN {choice_options} co ON co.choiceid = ch.id

            INNER JOIN {choice_answers} ca ON ca.optionid = co.id AND ca.choiceid = ch.id

                 WHERE c.id {$contextsql}

                       AND ca.userid = :userid

              ORDER BY cm.id";

        $params = ['modname' => 'choice', 'contextlevel' => CONTEXT_MODULE, 'userid' => $user->id] + $contextparams;

        // Reference to the choice activity seen in the last iteration of the loop. By comparing this with the current record, and

        // because we know the results are ordered, we know when we've moved to the answers for a new choice activity and therefore

        // when we can export the complete data for the last activity.

        $lastcmid = null;

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

        foreach ($choiceanswers as $choiceanswer) {

            // If we've moved to a new choice, then write the last choice data and reinit the choice data array.

            if ($lastcmid != $choiceanswer->cmid) {

                if (!empty($choicedata)) {

                    $context = \context_module::instance($lastcmid);

                    self::export_choice_data_for_user($choicedata, $context, $user);

                }

                $choicedata = [

                    'answer' => [],

                    'timemodified' => \core_privacy\local\request\transform::datetime($choiceanswer->timemodified),

                ];

            }

            $choicedata['answer'][] = $choiceanswer->answer;

            $lastcmid = $choiceanswer->cmid;

        }

        $choiceanswers->close();

        // The data for the last activity won't have been written yet, so make sure to write it now!

        if (!empty($choicedata)) {

            $context = \context_module::instance($lastcmid);

            self::export_choice_data_for_user($choicedata, $context, $user);

        }

    }

    /**

     * Export the supplied personal data for a single choice activity, along with any generic data or area files.

     *

     * @param array $choicedata the personal data to export for the choice.

     * @param \context_module $context the context of the choice.

     * @param \stdClass $user the user record

     */

    protected static function export_choice_data_for_user(array $choicedata, \context_module $context, \stdClass $user) {

        // Fetch the generic module data for the choice.

        $contextdata = helper::get_context_data($context, $user);

        // Merge with choice data and write it.

        $contextdata = (object)array_merge((array)$contextdata, $choicedata);

        writer::with_context($context)->export_data([], $contextdata);

        // Write generic module intro files.

        helper::export_context_files($context, $user);

    }

    /**

     * Delete all data for all users in the specified context.

     *

     * @param \context $context the context to delete in.

     */

    public static function delete_data_for_all_users_in_context(\context $context) {

        global $DB;

        if (!$context instanceof \context_module) {

            return;

        }

        if ($cm = get_coursemodule_from_id('choice', $context->instanceid)) {

            $DB->delete_records('choice_answers', ['choiceid' => $cm->instance]);

        }

    }

    /**

     * Delete all user data for the specified user, in the specified contexts.

     *

     * @param approved_contextlist $contextlist a list of contexts approved for deletion.

     */

    public static function delete_data_for_user(approved_contextlist $contextlist) {

        global $DB;

        if (empty($contextlist->count())) {

            return;

        }

        $userid = $contextlist->get_user()->id;

        foreach ($contextlist->get_contexts() as $context) {

            if (!$context instanceof \context_module) {

                continue;

            }

            $instanceid = $DB->get_field('course_modules', 'instance', ['id' => $context->instanceid]);

            if (!$instanceid) {

                continue;

            }

            $DB->delete_records('choice_answers', ['choiceid' => $instanceid, 'userid' => $userid]);

        }

    }

    /**

     * Delete multiple users within a single context.

     *

     * @param   approved_userlist       $userlist The approved context and user information to delete information for.

     */

    public static function delete_data_for_users(approved_userlist $userlist) {

        global $DB;

        $context = $userlist->get_context();

        if (!$context instanceof \context_module) {

            return;

        }

        $cm = get_coursemodule_from_id('choice', $context->instanceid);

        if (!$cm) {

            // Only choice module will be handled.

            return;

        }

        $userids = $userlist->get_userids();

        list($usersql, $userparams) = $DB->get_in_or_equal($userids, SQL_PARAMS_NAMED);

        $select = "choiceid = :choiceid AND userid $usersql";

        $params = ['choiceid' => $cm->instance] + $userparams;

        $DB->delete_records_select('choice_answers', $select, $params);

    }

}