MDL-61998 cohort: Implement privacy API

cohort/classes/privacy/provider.php

@@ -0,0 +1,194 @@
+<?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 class for requesting user data.
+ *
+ * @package    core_cohort
+ * @copyright  2018 Sara Arjona <sara@moodle.com>
+ * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
+ */
+
+namespace core_cohort\privacy;
+
+defined('MOODLE_INTERNAL') || die();
+
+use core_privacy\local\metadata\collection;
+use core_privacy\local\request\contextlist;
+use core_privacy\local\request\approved_contextlist;
+use core_privacy\local\request\transform;
+use core_privacy\local\request\writer;
+
+/**
+ * Privacy class for requesting user data.
+ *
+ * @copyright  2018 Sara Arjona <sara@moodle.com>
+ * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
+ */
+class provider implements
+        \core_privacy\local\metadata\provider,
+        \core_privacy\local\request\plugin\provider {
+
+    /**
+     * Return the fields which contain personal data.
+     *
+     * @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('cohort_members', [
+                'cohortid' => 'privacy:metadata:cohort_members:cohortid',
+                'userid' => 'privacy:metadata:cohort_members:userid',
+                'timeadded' => 'privacy:metadata:cohort_members:timeadded'
+            ], 'privacy:metadata:cohort_members');
+        return $collection;
+    }
+
+    /**
+     * Get the list of contexts that contain user information for the specified user.
+     *
+     * @param int $userid The user to search.
+     * @return contextlist $contextlist The contextlist containing the list of contexts used in this plugin.
+     */
+    public static function get_contexts_for_userid(int $userid) : contextlist {
+        $sql = "SELECT ctx.id
+                  FROM {context} ctx
+            INNER JOIN {cohort} c ON c.contextid = ctx.id
+            INNER JOIN {cohort_members} cm ON cm.cohortid = c.id
+                 WHERE cm.userid = :userid AND (ctx.contextlevel = :contextlevel1 OR ctx.contextlevel = :contextlevel2)";
+        $params = [
+            'userid'        => $userid,
+            'contextlevel1' => CONTEXT_SYSTEM,
+            'contextlevel2' => CONTEXT_COURSECAT,
+        ];
+        $contextlist = new contextlist();
+        $contextlist->add_from_sql($sql, $params);
+
+        return $contextlist;
+    }
+
+    /**
+     * 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) {
+        global $DB;
+
+        // Remove contexts different from SYSTEM or COURSECAT.
+        $contexts = array_reduce($contextlist->get_contexts(), function($carry, $context) {
+            if ($context->contextlevel == CONTEXT_SYSTEM || $context->contextlevel == CONTEXT_COURSECAT) {
+                $carry[] = $context->id;
+            }
+            return $carry;
+        }, []);
+
+        if (empty($contexts)) {
+            return;
+        }
+
+        // Get cohort data.
+        $userid = $contextlist->get_user()->id;
+        list($contextsql, $contextparams) = $DB->get_in_or_equal($contexts, SQL_PARAMS_NAMED);
+        $sql = "SELECT c.name,
+                       c.idnumber,
+                       c.description,
+                       c.visible,
+                       cm.timeadded,
+                       ctx.id as contextid
+                  FROM {context} ctx
+            INNER JOIN {cohort} c ON c.contextid = ctx.id
+            INNER JOIN {cohort_members} cm ON cm.cohortid = c.id
+                 WHERE ctx.id {$contextsql}
+                       AND cm.userid = :userid";
+        $params = [
+                'userid'        => $userid
+            ] + $contextparams;
+
+        $cohorts = $DB->get_recordset_sql($sql, $params);
+        foreach ($cohorts as $cohort) {
+            $alldata[$cohort->contextid][] = (object)[
+                    'name' => $cohort->name,
+                    'idnumber' => $cohort->idnumber,
+                    'visible' => transform::yesno($cohort->visible),
+                    'timeadded' => transform::datetime($cohort->timeadded),
+                ];
+        }
+        $cohorts->close();
+
+        // Export cohort data.
+        array_walk($alldata, function($data, $contextid) {
+            $context = \context::instance_by_id($contextid);
+            writer::with_context($context)->export_related_data([], 'cohort', $data);
+        });
+
+    }
+
+    /**
+     * Delete all use data which matches the specified context.
+     *
+     * @param context $context A user context.
+     */
+    public static function delete_data_for_all_users_in_context(\context $context) {
+        if (empty($context)) {
+            return;
+        }
+
+        if (!$context instanceof \context_system && !$context instanceof \context_coursecat) {
+            return;
+        }
+
+        static::delete_data($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 $contextlist) {
+        if (empty($contextlist->count())) {
+            return;
+        }
+
+        $userid = $contextlist->get_user()->id;
+        foreach ($contextlist->get_contexts() as $context) {
+            if (!$context instanceof \context_system && !$context instanceof \context_coursecat) {
+                return;
+            }
+            static::delete_data($context, $userid);
+        }
+    }
+
+    /**
+     * Delete data related to a context and user (if defined).
+     *
+     * @param context $context A context.
+     * @param int $userid The user ID.
+     */
+    protected static function delete_data(\context $context, int $userid = null) {
+        global $DB;
+
+        $cohortids = $DB->get_fieldset_select('cohort', 'id', 'contextid = :contextid', ['contextid' => $context->id]);
+        foreach ($cohortids as $cohortid) {
+            $params = ['cohortid' => $cohortid];
+            if (!empty($userid)) {
+                $params['userid'] = $userid;
+            }
+            $DB->delete_records('cohort_members', $params);
+        }
+    }
+}