MDL-22151 assignment backup - added backup for assignment with subplugin support MDL-22245

mod/assignment/type/offline/backup/moodle2/backup_assignment_offline_subplugin.class.php

@@ -0,0 +1,112 @@
+<?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/>.
+
+/**
+ * @package moodlecore
+ * @subpackage backup-moodle2
+ * @copyright 2010 onwards Eloy Lafuente (stronk7) {@link http://stronk7.com}
+ * @license   http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
+ */
+
+/**
+ * backup subplugin class that provides the necessary information
+ * needed to backup one assignment->offline subplugin.
+ *
+ * Note: Offline assignments really haven't any special subplugin
+ * information to backup/restore, hence code below is skipped (return false)
+ * but it's a good example of sublugins supported at different
+ * elements (assignment and submission) and conditions
+ */
+class backup_assignment_offline_subplugin extends backup_subplugin {
+
+    /**
+     * Returns the subplugin information to attach at assignment element
+     */
+    protected function define_assignment_subplugin_structure($connectionpoint) {
+
+        return false; // This subplugin backup is only one example. Skip it.
+
+        /**
+         * Any activity sublugins is always rooted by one backup_subplugin_element()
+         * Those elements have some unique characteristics:
+         *  - They are, basically, backup_nested_elements
+         *  - They cannot have attributes
+         *  - They don't have XML representations (only their final/child elements have
+         *  - They are able to specify one condition in order to decide if the subplugin
+         *    must be processed or no (usually we'll put the "type" condition here, but some
+         *    activities, may prefer not to use any condition, see workshop)
+         */
+
+        /**
+         * Here we are defining the information that will be attached, within the "assignment" element
+         * when assignments of type "offline" are sent to backup, so we define the backup_subplugin_element
+         * as not having any final element (null) and with the condition of the '/assignment/assignmenttype'
+         * being 'offline' (that will be checked on execution)
+         *
+         * Note that, while, we allow direct "injection" of final_elements at the "assignment" level (without
+         * any nesting, we ususally pass 'null', and later enclose the real subplugin information into deeper
+         * levels (get_recommended_name() and 'config' in the example below). That will make things
+         * on restore easier, as far as subplugin information will be clearly separted from module information.
+         */
+        $subplugin = $this->get_subplugin_element($connectionpoint, null, '/assignment/assignmenttype', 'offline');
+
+        /**
+         * Here we define the real structure the subplugin is going to generate - see note above. Obviously the
+         * example below hasn't sense at all, we are exporting the whole config table that is 100% unrelated
+         * with assignments. Take it as just one example. The only important bit is that it's highly recommened to
+         * use some exclusive name in the main nested element (something that won't conflict with other subplugins/parts).
+         * So we are using 'assignment_assignment_offline' as name here (the type of the subplugin, the name of the
+         * subplugin and the name of the connection point). get_recommended_name() will help, in any case ;-)
+         *
+         * All the code below is 100% standard backup structure code, so you define the structure, the sources,
+         * annotations... whatever you need
+         */
+        $assassoff = new backup_nested_element($this->get_recommended_name($connectionpoint));
+        $config = new backup_nested_element('config', null, array('name', 'value'));
+
+        $subplugin->add_child($assassoff);
+        $assassoff->add_child($config);
+
+        $config->set_source_table('config', array());
+
+        return $subplugin; // And we return the root subplugin element
+    }
+
+    /**
+     * Returns the subplugin information to attach at submission element
+     */
+    protected function define_submission_subplugin_structure($connectionpoint) {
+
+        return false; // This subplugin backup is only one example. Skip it.
+
+        // remember this has not XML representation
+        $subplugin = $this->get_subplugin_element($connectionpoint, null, '/assignment/assignmenttype', 'offline');
+
+        // type of the subplugin, name of the subplugin and name of the connection point (recommended)
+        $asssuboff = new backup_nested_element($this->get_recommended_name($connectionpoint));
+        // Why 'submission_config' name? Because it must be unique in the hierharchy and we
+        // already are using 'config' above withing the same file
+        $config = new backup_nested_element('submission_config', null, array('name', 'value'));
+
+        $subplugin->add_child($asssuboff);
+        $asssuboff->add_child($config);
+
+        $config->set_source_table('config', array());
+
+        return $subplugin; // And we return the root subplugin element
+    }
+}