MDL-61307 core_privacy: Add legacy polyfill for contrib plugins

This legacy polyfill allows plugin developers who release a single
branch to work with multiple versions of Moodle to support the API in
both Moodle 3.3 with PHP 5.6, and later versions.

privacy/classes/local/legacy_polyfill.php

@@ -0,0 +1,106 @@
+<?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/>.
+
+/**
+ * This file contains the polyfill to allow a plugin to operate with Moodle 3.3 up.
+ *
+ * @package core_privacy
+ * @copyright 2018 Andrew Nicols <[email protected]>
+ * @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
+ */
+namespace core_privacy\local;
+
+use \core_privacy\local\metadata\collection;
+use \core_privacy\local\request\contextlist;
+use \core_privacy\local\request\approved_contextlist;
+use \core_privacy\local\request\deletion_criteria;
+
+defined('MOODLE_INTERNAL') || die();
+
+/**
+ * The trait used to provide a backwards compatability for third-party plugins.
+ *
+ * @copyright 2018 Andrew Nicols <[email protected]>
+ * @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
+ */
+trait legacy_polyfill {
+
+    /**
+     * Get the language string identifier with the component's language
+     * file to explain why this plugin stores no data.
+     *
+     * @return  string
+     */
+    public static function get_reason() : string {
+        return static::_get_reason();
+    }
+
+    /**
+     * Get the list of items.
+     *
+     * @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 $collection) : collection  {
+        return static::_get_metadata($collection);
+    }
+
+    /**
+     * Export all user preferences for the plugin.
+     *
+     * @param   int         $userid The userid of the user whose data is to be exported.
+     */
+    public static function export_user_preferences(int $userid) {
+        return static::_export_user_preferences($userid);
+    }
+
+    /**
+     * 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 $userid) : contextlist {
+        return static::_get_contexts_for_userid($userid);
+    }
+
+    /**
+     * 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 $contextlist) {
+        return static::_export_user_data($contextlist);
+    }
+
+    /**
+     * Delete all use data which matches the specified deletion_criteria.
+     *
+     * @param   deletion_criteria       $criteria   An object containing specific deletion criteria to delete for.
+     */
+    public static function delete_for_context(deletion_criteria $criteria) {
+        return static::_delete_for_context($criteria);
+    }
+
+    /**
+     * 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_user_data(approved_contextlist $contextlist) {
+        return static::_delete_user_data($contextlist);
+    }
+}

privacy/tests/legacy_polyfill_test.php

@@ -0,0 +1,268 @@
+<?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/>.
+
+/**
+ * Unit tests for the privacy legacy polyfill.
+ *
+ * @package     core_privacy
+ * @category    test
+ * @copyright   2018 Andrew Nicols <[email protected]>
+ * @license     http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
+ */
+
+defined('MOODLE_INTERNAL') || die();
+
+global $CFG;
+
+use \core_privacy\local\metadata\collection;
+use \core_privacy\local\request\contextlist;
+use \core_privacy\local\request\deletion_criteria;
+use \core_privacy\local\request\approved_contextlist;
+
+/**
+ * Tests for the \core_privacy API's types\user_preference functionality.
+ * Unit tests for the Privacy API's legacy_polyfill.
+ *
+ * @copyright   2018 Andrew Nicols <[email protected]>
+ * @license     http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
+ */
+class core_privacy_legacy_polyfill_test extends advanced_testcase {
+    /**
+     * Test that the null_provider polyfill works and that the static _get_reason can be
+     * successfully called.
+     */
+    public function test_null_provider() {
+        $this->assertEquals('thisisareason', test_legacy_polyfill_null_provider::get_reason());
+    }
+
+    /**
+     * Test that the metdata\provider polyfill works and that the static _get_metadata can be
+     * successfully called.
+     */
+    public function test_metadata_provider() {
+        $collection = new collection('core_privacy');
+        $this->assertSame($collection, test_legacy_polyfill_metadata_provider::get_metadata($collection));
+    }
+
+    /**
+     * Test that the local\request\user_preference_provider polyfill works and that the static
+     * _export_user_preferences can be successfully called.
+     */
+    public function test_user_preference_provider() {
+        $userid = 417;
+
+        $mock = $this->createMock(test_legacy_polyfill_mock_wrapper::class);
+        $mock->expects($this->once())
+            ->method('get_return_value')
+            ->with('_export_user_preferences', [$userid])
+            ->willReturn(null);
+
+        test_legacy_polyfill_user_preference_provider::$mock = $mock;
+        test_legacy_polyfill_user_preference_provider::export_user_preferences($userid);
+    }
+
+    /**
+     * Test that the local\request\core_user_preference_provider polyfill works and that the static
+     * _get_contexts_for_userid can be successfully called.
+     */
+    public function test_get_contexts_for_userid() {
+        $userid = 417;
+        $contextlist = new contextlist('core_privacy');
+
+        $mock = $this->createMock(test_legacy_polyfill_mock_wrapper::class);
+        $mock->expects($this->once())
+            ->method('get_return_value')
+            ->with('_get_contexts_for_userid', [$userid])
+            ->willReturn($contextlist);
+
+        test_legacy_polyfill_request_provider::$mock = $mock;
+        $result = test_legacy_polyfill_request_provider::get_contexts_for_userid($userid);
+        $this->assertSame($contextlist, $result);
+    }
+
+    /**
+     * Test that the local\request\core_user_preference_provider polyfill works and that the static
+     * _export_user_data can be successfully called.
+     */
+    public function test_export_user_data() {
+        $contextlist = new approved_contextlist(\core_user::get_user_by_username('admin'), 'core_privacy', [98]);
+
+        $mock = $this->createMock(test_legacy_polyfill_mock_wrapper::class);
+        $mock->expects($this->once())
+            ->method('get_return_value')
+            ->with('_export_user_data', [$contextlist]);
+
+        test_legacy_polyfill_request_provider::$mock = $mock;
+        test_legacy_polyfill_request_provider::export_user_data($contextlist);
+    }
+
+    /**
+     * Test that the local\request\core_user_preference_provider polyfill works and that the static
+     * _delete_for_context can be successfully called.
+     */
+    public function test_delete_for_context() {
+        $criteria = new deletion_criteria(\context_system::instance());
+
+        $mock = $this->createMock(test_legacy_polyfill_mock_wrapper::class);
+        $mock->expects($this->once())
+            ->method('get_return_value')
+            ->with('_delete_for_context', [$criteria]);
+
+        test_legacy_polyfill_request_provider::$mock = $mock;
+        test_legacy_polyfill_request_provider::delete_for_context($criteria);
+    }
+
+    /**
+     * Test that the local\request\core_user_preference_provider polyfill works and that the static
+     * _delete_user_data can be successfully called.
+     */
+    public function test_delete_user_data() {
+        $contextlist = new approved_contextlist(\core_user::get_user_by_username('admin'), 'core_privacy', [98]);
+
+        $mock = $this->createMock(test_legacy_polyfill_mock_wrapper::class);
+        $mock->expects($this->once())
+            ->method('get_return_value')
+            ->with('_delete_user_data', [$contextlist]);
+
+        test_legacy_polyfill_request_provider::$mock = $mock;
+        test_legacy_polyfill_request_provider::delete_user_data($contextlist);
+    }
+}
+
+/**
+ * Legacy polyfill test for the null provider.
+ *
+ * @copyright   2018 Andrew Nicols <[email protected]>
+ * @license     http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
+ */
+class test_legacy_polyfill_null_provider implements \core_privacy\local\metadata\null_provider {
+
+    use \core_privacy\local\legacy_polyfill;
+
+    /**
+     * Test for get_reason
+     */
+    protected static function _get_reason() {
+        return 'thisisareason';
+    }
+}
+
+/**
+ * Legacy polyfill test for the metadata provider.
+ *
+ * @copyright   2018 Andrew Nicols <[email protected]>
+ * @license     http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
+ */
+class test_legacy_polyfill_metadata_provider implements \core_privacy\local\metadata\provider {
+
+    use \core_privacy\local\legacy_polyfill;
+
+    /**
+     * Test for get_metadata.
+     *
+     * @param   collection     $collection The initialised collection to add items to.
+     * @return  collection     A listing of user data stored through this system.
+     */
+    protected static function _get_metadata(collection $collection) {
+        return $collection;
+    }
+}
+
+/**
+ * Legacy polyfill test for the metadata provider.
+ *
+ * @copyright   2018 Andrew Nicols <[email protected]>
+ * @license     http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
+ */
+class test_legacy_polyfill_user_preference_provider implements \core_privacy\local\request\user_preference_provider {
+
+    use \core_privacy\local\legacy_polyfill;
+
+    /**
+     * @var test_legacy_polyfill_request_provider $mock
+     */
+    public static $mock = null;
+
+    /**
+     * Export all user preferences for the plugin.
+     *
+     * @param   int         $userid The userid of the user whose data is to be exported.
+     */
+    protected static function _export_user_preferences($userid) {
+        return static::$mock->get_return_value(__FUNCTION__, func_get_args());
+    }
+}
+
+/**
+ * Legacy polyfill test for the request provider.
+ *
+ * @copyright   2018 Andrew Nicols <[email protected]>
+ * @license     http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
+ */
+class test_legacy_polyfill_request_provider implements \core_privacy\local\request\core_user_data_provider {
+
+    use \core_privacy\local\legacy_polyfill;
+
+    /**
+     * @var test_legacy_polyfill_request_provider $mock
+     */
+    public static $mock = null;
+
+    /**
+     * Test for get_contexts_for_userid.
+     *
+     * @param   int         $userid     The user to search.
+     * @return  contextlist   $contextlist  The contextlist containing the list of contexts used in this plugin.
+     */
+    protected static function _get_contexts_for_userid($userid) {
+        return static::$mock->get_return_value(__FUNCTION__, func_get_args());
+    }
+
+    /**
+     * Test for export_user_data.
+     *
+     * @param   approved_contextlist    $contextlist    The approved contexts to export information for.
+     */
+    protected static function _export_user_data(approved_contextlist $contextlist) {
+        return static::$mock->get_return_value(__FUNCTION__, func_get_args());
+    }
+
+
+    /**
+     * Delete all use data which matches the specified deletion_criteria.
+     *
+     * @param   deletion_criteria       $criteria   An object containing specific deletion criteria to delete for.
+     */
+    public static function _delete_for_context(deletion_criteria $criteria) {
+        return static::$mock->get_return_value(__FUNCTION__, func_get_args());
+    }
+
+    /**
+     * 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_user_data(approved_contextlist $contextlist) {
+        return static::$mock->get_return_value(__FUNCTION__, func_get_args());
+    }
+}
+
+class test_legacy_polyfill_mock_wrapper {
+    /**
+     * Get the return value for the specified item.
+     */
+    public function get_return_value() {}
+}