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 core_group.

 *

 * @package    core_group

 * @category   privacy

 * @copyright  2018 Shamim Rezaie <shamim@moodle.com>

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

 */

namespace core_group\privacy;

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

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\transform;

use core_privacy\local\request\userlist;

/**

 * Privacy Subsystem implementation for core_group.

 *

 * @copyright  2018 Shamim Rezaie <shamim@moodle.com>

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

 */

class provider implements

        // Groups store user data.

        \core_privacy\local\metadata\provider,

        // The group subsystem contains user's group memberships.

        \core_privacy\local\request\subsystem\provider,

        // The group subsystem can provide information to other plugins.

        \core_privacy\local\request\subsystem\plugin_provider,

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

        \core_privacy\local\request\core_userlist_provider,

        \core_privacy\local\request\shared_userlist_provider

    {

    /**

     * Returns meta data about this system.

     *

     * @param   collection $collection The initialised collection to add items to.

     * @return  collection A listing of user data stored through this system.

     */

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

        $collection->add_database_table('groups_members', [

            'groupid' => 'privacy:metadata:groups:groupid',

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

            'timeadded' => 'privacy:metadata:groups:timeadded',

        ], 'privacy:metadata:groups');

        $collection->link_subsystem('core_message', 'privacy:metadata:core_message');

        return $collection;

    }

    /**

     * Writes user data to the writer for the user to download.

     *

     * @param \context  $context    The context to export data for.

     * @param string    $component  The component that is calling this function. Empty string means no component.

     * @param array     $subcontext The sub-context in which to export this data.

     * @param int       $itemid     Optional itemid associated with component.

     */

    public static function export_groups(\context $context, string $component, array $subcontext = [], int $itemid = 0) {

        global $DB, $USER;

        if (!$context instanceof \context_course) {

            return;

        }

        $subcontext[] = get_string('groups', 'core_group');

        $sql = "SELECT gm.id, gm.timeadded, gm.userid, g.name, gm.groupid

                  FROM {groups_members} gm

                  JOIN {groups} g ON gm.groupid = g.id

                 WHERE g.courseid = :courseid

                       AND gm.component = :component

                       AND gm.userid = :userid";

        $params = [

            'courseid'  => $context->instanceid,

            'component' => $component,

            'userid'    => $USER->id

        ];

        if ($itemid) {

            $sql .= ' AND gm.itemid = :itemid';

            $params['itemid'] = $itemid;

        }

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

        $groupstoexport = array_map(function($group) {

            return (object) [

                'name' => format_string($group->name),

                'timeadded' => transform::datetime($group->timeadded),

            ];

        }, $groups);

        if (!empty($groups)) {

            \core_privacy\local\request\writer::with_context($context)

                    ->export_data($subcontext, (object) [

                        'groups' => $groupstoexport,

                    ]);

            foreach ($groups as $group) {

                // Export associated conversations to this group.

                \core_message\privacy\provider::export_conversations($USER->id, 'core_group', 'groups',

                    $context, [], $group->groupid);

            }

        }

    }

    /**

     * Deletes all group memberships for a specified context and component.

     *

     * @param \context  $context    Details about which context to delete group memberships for.

     * @param string    $component  Component to delete. Empty string means no component (manual group memberships).

     * @param int       $itemid     Optional itemid associated with component.

     */

    public static function delete_groups_for_all_users(\context $context, string $component, int $itemid = 0) {

        global $DB;

        if (!$context instanceof \context_course) {

            return;

        }

        if (!$DB->record_exists('groups', ['courseid' => $context->instanceid])) {

            return;

        }

        $select = "component = :component AND groupid IN (SELECT g.id FROM {groups} g WHERE courseid = :courseid)";

        $params = ['component' => $component, 'courseid' => $context->instanceid];

        if ($itemid) {

            $select .= ' AND itemid = :itemid';

            $params['itemid'] = $itemid;

        }

        // Delete the group conversations.

        $groups = $DB->get_records_select('groups_members', $select, $params);

        foreach ($groups as $group) {

            \core_message\privacy\provider::delete_conversations_for_all_users($context, 'core_group', 'groups', $group->groupid);

        }

        // Remove members from the group.

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

        // Purge the group and grouping cache for users.

        \cache_helper::purge_by_definition('core', 'user_group_groupings');

    }

    /**

     * Deletes all records for a user from a list of approved contexts.

     *

     * @param approved_contextlist  $contextlist    Contains the user ID and a list of contexts to be deleted from.

     * @param string                $component      Component to delete from. Empty string means no component (manual memberships).

     * @param int                   $itemid         Optional itemid associated with component.

     */

    public static function delete_groups_for_user(approved_contextlist $contextlist, string $component, int $itemid = 0) {

        global $DB;

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

        $contextids = $contextlist->get_contextids();

        if (!$contextids) {

            return;

        }

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

        $contextparams += ['contextcourse' => CONTEXT_COURSE];

        $groupselect = "SELECT g.id

                          FROM {groups} g

                          JOIN {context} ctx ON g.courseid = ctx.instanceid AND ctx.contextlevel = :contextcourse

                         WHERE ctx.id $contextsql";

        if (!$DB->record_exists_sql($groupselect, $contextparams)) {

            return;

        }

        $select = "userid = :userid AND component = :component AND groupid IN ({$groupselect})";

        $params = ['userid' => $userid, 'component' => $component] + $contextparams;

        if ($itemid) {

            $select .= ' AND itemid = :itemid';

            $params['itemid'] = $itemid;

        }

        // Delete the group conversations.

        $groups = $DB->get_records_select('groups_members', $select, $params);

        foreach ($groups as $group) {

            \core_message\privacy\provider::delete_conversations_for_user($contextlist, 'core_group', 'groups', $group->groupid);

        }

        // Remove members from the group.

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

        // Invalidate the group and grouping cache for the user.

        \cache_helper::invalidate_by_definition('core', 'user_group_groupings', array(), array($userid));

    }

    /**

     * Add the list of users who are members of some groups in the specified constraints.

     *

     * @param   userlist    $userlist   The userlist to add the users to.

     * @param   string      $component  The component to check.

     * @param   int         $itemid     Optional itemid associated with component.

     */

    public static function get_group_members_in_context(userlist $userlist, string $component, int $itemid = 0) {

        $context = $userlist->get_context();

        if (!$context instanceof \context_course) {

            return;

        }

        // Group members in the given context.

        $sql = "SELECT gm.userid

                  FROM {groups_members} gm

                  JOIN {groups} g ON gm.groupid = g.id

                 WHERE g.courseid = :courseid AND gm.component = :component";

        $params = [

            'courseid'      => $context->instanceid,

            'component'     => $component

        ];

        if ($itemid) {

            $sql .= ' AND gm.itemid = :itemid';

            $params['itemid'] = $itemid;

        }

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

        // Get the users with some group conversation in this context.

        \core_message\privacy\provider::add_conversations_in_context($userlist, 'core_group', 'groups', $itemid);

    }

    /**

     * Deletes all records for multiple users within a single context.

     *

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

     * @param string            $component  Component to delete from. Empty string means no component (manual memberships).

     * @param int               $itemid     Optional itemid associated with component.

     */

    public static function delete_groups_for_users(approved_userlist $userlist, string $component, int $itemid = 0) {

        global $DB;

        $context = $userlist->get_context();

        $userids = $userlist->get_userids();

        if (!$context instanceof \context_course) {

            return;

        }

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

        $groupselect = "SELECT id FROM {groups} WHERE courseid = :courseid";

        $groupparams = ['courseid' => $context->instanceid];

        $select = "component = :component AND userid {$usersql} AND groupid IN ({$groupselect})";

        $params = ['component' => $component] + $groupparams + $userparams;

        if ($itemid) {

            $select .= ' AND itemid = :itemid';

            $params['itemid'] = $itemid;

        }

        // Delete the group conversations for these users.

        $groups = $DB->get_records_select('groups_members', $select, $params);

        foreach ($groups as $group) {

            \core_message\privacy\provider::delete_conversations_for_users($userlist, 'core_group', 'groups', $group->groupid);

        }

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

        // Invalidate the group and grouping cache for the user.

        \cache_helper::invalidate_by_definition('core', 'user_group_groupings', array(), $userids);

    }

    /**

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

     *

     * @param   int     $userid     The user to search.

     * @param   string  $component  The component to check.

     * @param   int     $itemid     Optional itemid associated with component.

     * @return  contextlist         The contextlist containing the list of contexts.

     */

    public static function get_contexts_for_group_member(int $userid, string $component, int $itemid = 0) {

        $contextlist = new contextlist();

        $sql = "SELECT ctx.id

                  FROM {groups_members} gm

                  JOIN {groups} g ON gm.groupid = g.id

                  JOIN {context} ctx ON g.courseid = ctx.instanceid AND ctx.contextlevel = :contextcourse

                 WHERE gm.userid = :userid AND gm.component = :component";

        $params = [

            'contextcourse' => CONTEXT_COURSE,

            'userid'        => $userid,

            'component'     => $component

        ];

        if ($itemid) {

            $sql .= ' AND gm.itemid = :itemid';

            $params['itemid'] = $itemid;

        }

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

        // Get the contexts where the userid has group conversations.

        \core_message\privacy\provider::add_contexts_for_conversations($contextlist, $userid, 'core_group', 'groups', $itemid);

        return $contextlist;

    }

    /**

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

     *

     * @param   int $userid The user to search.

     * @return  contextlist The contextlist containing the list of contexts used in this plugin.

     */

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

        return static::get_contexts_for_group_member($userid, '');

    }

    /**

     * 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_course) {

            return;

        }

        static::get_group_members_in_context($userlist, '');

    }

    /**

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

     *

     * @param approved_contextlist $contextlist The approved contexts to export information for.

     */

    public static function export_user_data(approved_contextlist $contextlist) {

        $contexts = $contextlist->get_contexts();

        foreach ($contexts as $context) {

            static::export_groups($context, '');

        }

    }

    /**

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

     *

     * @param context $context The specific context to delete data for.

     */

    public static function delete_data_for_all_users_in_context(\context $context) {

        static::delete_groups_for_all_users($context, '');

    }

    /**

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

     *

     * @param approved_contextlist $contextlist The approved contexts and user information to delete information for.

     */

    public static function delete_data_for_user(approved_contextlist $contextlist) {

        static::delete_groups_for_user($contextlist, '');

    }

    /**

     * 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) {

        static::delete_groups_for_users($userlist, '');

    }

}