MDL-61307 core_tag: Add implementation of privacy API

lang/en/tag.php

@@ -92,6 +92,19 @@
 $string['nothingtoupdate'] = 'Nothing to update';
 $string['owner'] = 'Owner';
 $string['prevpage'] = 'Back';
+$string['privacy:metadata:tag'] = 'The details of each unique tag are stored alongside their description and other related information';
+$string['privacy:metadataetag:name'] = 'The name of the tag - this is the normalised version of the name.';
+$string['privacy:metadata:tag:rawname'] = 'The name of the tag - this is the display name.';
+$string['privacy:metadata:tag:description'] = 'The description of the tag.';
+$string['privacy:metadata:tag:flag'] = 'Whether a tag has been flagged as inappropriate.';
+$string['privacy:metadata:tag:timemodified'] = 'The last time that the tag was last modified.';
+$string['privacy:metadata:tag:userid'] = 'The user who first created the tag.';
+$string['privacy:metadata:taginstance'] = 'The link between each tag and where it is used.';
+$string['privacy:metadata:taginstance:tagid'] = 'The link to the tag.';
+$string['privacy:metadata:taginstance:ordering'] = 'The relative order of this tag.';
+$string['privacy:metadata:taginstance:timecreated'] = 'The time that this tag was linked to the target.';
+$string['privacy:metadata:taginstance:timemodified'] = 'The time that this tag was last modified for the target.';
+$string['privacy:metadata:taginstance:tiuserid'] = 'Where shared content can be individually tagged by users, tThe owner of the tag instance is stored.';
 $string['ptags'] = 'User defined tags (Comma separated)';
 $string['relatedblogs'] = 'Most recent blog entries';
 $string['relatedtags'] = 'Related tags';

tag/classes/privacy/provider.php

@@ -0,0 +1,149 @@
+<?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_tag.
+ *
+ * @package    core_tag
+ * @copyright  2018 Zig Tan <zig@moodle.com>
+ * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
+ */
+
+namespace core_tag\privacy;
+
+defined('MOODLE_INTERNAL') || die();
+
+use \core_privacy\local\metadata\collection;
+
+/**
+ * Privacy Subsystem implementation for core_tag.
+ *
+ * @copyright  2018 Zig Tan <zig@moodle.com>
+ * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
+ */
+class provider implements
+        // Tags store user data.
+        \core_privacy\local\metadata\provider,
+
+        // The tag subsystem provides data to other components.
+        \core_privacy\local\request\subsystem\plugin_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 {
+        // The table 'tag' contains data that a user has entered.
+        // It is currently linked with a userid, but this field will hopefulyl go away.
+        // Note: The userid is not necessarily 100% accurate. See MDL-61555.
+        $collection->add_database_table('tag', [
+                'name' => 'privacy:metadata:tag:name',
+                'rawname' => 'privacy:metadata:tag:rawname',
+                'description' => 'privacy:metadata:tag:description',
+                'flag' => 'privacy:metadata:tag:flag',
+                'timemodified' => 'privacy:metadata:tag:timemodified',
+                'userid' => 'privacy:metadata:tag:userid',
+            ], 'privacy:metadata:tag');
+
+        // The table 'tag_instance' contains user data.
+        // It links the user of a specific tag, to the item which is tagged.
+        // In some cases the userid who 'owns' the tag is also stored.
+        $collection->add_database_table('tag_instance', [
+                'tagid' => 'privacy:metadata:taginstance:tagid',
+                'ordering' => 'privacy:metadata:taginstance:ordering',
+                'timecreated' => 'privacy:metadata:taginstance:timecreated',
+                'timemodified' => 'privacy:metadata:taginstance:timemodified',
+                'tiuserid' => 'privacy:metadata:taginstance:tiuserid',
+            ], 'privacy:metadata:taginstance');
+
+        // The table 'tag_area' does not contain any specific user data.
+        // It links components and item types to collections and describes how they can be associated.
+
+        // The table 'tag_coll' does not contain any specific user data.
+        // It describes a list of tag collections configured by the administrator.
+
+        // The table 'tag_correlation' does not contain any user data.
+        // It is a cache for other data already stored.
+
+        return $collection;
+    }
+
+    /**
+     * Store all tags which match the specified component, itemtype, and itemid.
+     *
+     * In most situations you will want to specify $onlyuser as false.
+     * This will fetch only tags where the user themselves set the tag, or where tags are a shared resource.
+     *
+     * If you specify $onlyuser as true, only the tags created by that user will be included.
+     *
+     * @param   int         $userid The user whose information is to be exported
+     * @param   \context    $context The context to export for
+     * @param   array       $subcontext The subcontext within the context to export this information
+     * @param   string      $component The component to fetch data from
+     * @param   string      $itemtype The itemtype that the data was exported in within the component
+     * @param   int         $itemid The itemid within that tag
+     * @param   bool        $onlyuser Whether to only export ratings that the current user has made, or all tags
+     */
+    public static function export_item_tags(
+        int $userid,
+        \context $context,
+        array $subcontext,
+        string $component,
+        string $itemtype,
+        int $itemid,
+        bool $onlyuser = false
+    ) {
+        global $DB;
+
+        // Do not include the mdl_tag userid data because of bug with re-using existing tags by other users.
+        $sql = "SELECT
+                    t.id,
+                    t.tagcollid,
+                    t.name,
+                    t.rawname,
+                    t.isstandard,
+                    t.description,
+                    t.descriptionformat,
+                    t.flag,
+                    t.timemodified
+                  FROM {tag} t
+            INNER JOIN {tag_instance} ti ON ti.tagid = t.id
+                 WHERE ti.component = :component
+                   AND ti.itemtype = :itemtype
+                   AND ti.itemid = :itemid
+                   ";
+
+        if ($onlyuser) {
+            $sql .= "AND ti.tiuserid = :userid";
+        } else {
+            $sql .= "AND (ti.tiuserid = 0 OR ti.tiuserid = :userid)";
+        }
+
+        $params = [
+            'component' => $component,
+            'itemtype' => $itemtype,
+            'itemid' => $itemid,
+            'userid' => $userid,
+        ];
+
+        if ($tags = $DB->get_records_sql($sql, $params)) {
+            $writer = \core_privacy\local\request\writer::with_context($context)
+                ->export_related_data($subcontext, 'tags', $tags);
+        }
+    }
+}