Moodle backup code for stack questions.

Without the corresonding restore code, it is impossible to know if this
is really right, but the XML generated looks complete and plausible.

backup/moodle2/backup_qtype_stack_plugin.class.php

+<?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/>.
+
+/**
+ * STACK question type backup code.
+ * @package   qtype_stack
+ * @copyright 2012 The Open University
+ * @license   http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
+ */
+
+
+defined('MOODLE_INTERNAL') || die();
+
+
+/**
+ * Provides the information to backup STACK questions
+ *
+ * @copyright 2012 The Open University
+ * @license   http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
+ */
+class backup_qtype_stack_plugin extends backup_qtype_plugin {
+
+    /**
+     * @return backup_plugin_element the qtype information to attach to question element.
+     */
+    protected function define_question_plugin_structure() {
+
+        // Define the virtual plugin element with the condition to fulfill
+        $plugin = $this->get_plugin_element(null, '../../qtype', 'stack');
+
+        // Create one standard named plugin element (the visible container)
+        $pluginwrapper = new backup_nested_element($this->get_recommended_name());
+
+        // Connect the visible container ASAP
+        $plugin->add_child($pluginwrapper);
+
+        // Now create the necessary elements
+        $stackoptions = new backup_nested_element('stackoptions', array('id'),
+                array('questionvariables', 'specificfeedback', 'specificfeedbackformat',
+                      'questionnote', 'questionsimplify', 'assumepositive', 'markmode',
+                      'prtcorrect', 'prtcorrectformat', 'prtpartiallycorrect', 'prtpartiallycorrectformat',
+                      'prtincorrect', 'prtincorrectformat', 'multiplicationsign', 'sqrtsign', 'complexno'));
+
+        $stackinputs = new backup_nested_element('stackinputs');
+        $stackinput = new backup_nested_element('stackinput', array('id'),
+                array('name', 'type', 'tans', 'boxsize', 'strictsyntax', 'insertstars',
+                       'syntaxhint', 'forbidwords', 'forbidfloat', 'requirelowestterms',
+                       'checkanswertype', 'mustverify', 'showvalidation'));
+
+        $stackprts = new backup_nested_element('stackprts');
+        $stackprt = new backup_nested_element('stackprt', array('id'),
+                array('name', 'value', 'autosimplify', 'feedbackvariables'));
+
+        $stackprtnodes = new backup_nested_element('stackprtnodes');
+        $stackprtnode = new backup_nested_element('stackprtnode', array('id'),
+                array('nodename', 'answertest', 'sans', 'tans', 'testoptions', 'quiet',
+                      'truescoremode', 'truescore', 'truepenalty', 'truenextnode',
+                      'trueanswernote', 'truefeedback', 'truefeedbackformat',
+                      'falsescoremode', 'falsescore', 'falsepenalty', 'falsenextnode',
+                      'falseanswernote', 'falsefeedback', 'falsefeedbackformat'));
+
+        $stackqtests = new backup_nested_element('stackqtests');
+        $stackqtest = new backup_nested_element('stackqtest', array('id'), array('testcase'));
+
+        $stackqtestinputs = new backup_nested_element('stackqtestinputs');
+        $stackqtestinput = new backup_nested_element('stackqtestinput', array('id'),
+                array('inputname', 'value'));
+
+        $stackqtestexpecteds = new backup_nested_element('stackqtestexpecteds');
+        $stackqtestexpected = new backup_nested_element('stackqtestexpected', array('id'),
+                array('prtname', 'expectedscore', 'expectedpenalty', 'expectedanswernote'));
+
+        $stackdeployedseeds = new backup_nested_element('stackdeployedseeds');
+        $stackdeployedseed = new backup_nested_element('stackdeployedseed', array('id'), array('seed'));
+
+        // Build the tree
+        $pluginwrapper->add_child($stackoptions);
+
+        $pluginwrapper->add_child($stackinputs);
+        $stackinputs->add_child($stackinput);
+
+        $pluginwrapper->add_child($stackprts);
+        $stackprts->add_child($stackprt);
+        $stackprt->add_child($stackprtnodes);
+        $stackprtnodes->add_child($stackprtnode);
+
+        $pluginwrapper->add_child($stackqtests);
+        $stackqtests->add_child($stackqtest);
+        $stackqtest->add_child($stackqtestinputs);
+        $stackqtestinputs->add_child($stackqtestinput);
+        $stackqtest->add_child($stackqtestexpecteds);
+        $stackqtestexpecteds->add_child($stackqtestexpected);
+
+        $pluginwrapper->add_child($stackdeployedseeds);
+        $stackdeployedseeds->add_child($stackdeployedseed);
+
+        // set source to populate the data
+        $stackoptions->set_source_table('qtype_stack', array('questionid' => backup::VAR_PARENTID));
+        $stackinput->set_source_table('qtype_stack_inputs', array('questionid' => backup::VAR_PARENTID));
+        $stackprt->set_source_table('qtype_stack_prts', array('questionid' => backup::VAR_PARENTID));
+        $stackprtnode->set_source_table('qtype_stack_prt_nodes',
+                array('questionid' => '../../../../../../../id', 'prtname' => '../../name'));
+        $stackqtest->set_source_sql(
+                'SELECT * FROM {qtype_stack_qtests} WHERE questionid = ? ORDER BY testcase',
+                array(backup::VAR_PARENTID));
+        $stackqtestinput->set_source_table('qtype_stack_qtest_inputs',
+                array('questionid' => '../../../../../../../id', 'testcase' => '../../testcase'));
+        $stackqtestexpected->set_source_table('qtype_stack_qtest_expected',
+                array('questionid' => '../../../../../../../id', 'testcase' => '../../testcase'));
+        $stackdeployedseed->set_source_sql(
+                'SELECT * FROM {qtype_stack_deployed_seeds} WHERE questionid = ? ORDER BY id',
+                array(backup::VAR_PARENTID));
+
+        return $plugin;
+    }
+
+    /**
+     * Returns one array with filearea => mappingname elements for the qtype
+     *
+     * Used by {@link get_components_and_fileareas} to know about all the qtype
+     * files to be processed both in backup and restore.
+     */
+    public static function get_qtype_fileareas() {
+        return array(
+            'specificfeedback'    => 'qtype_stack',
+            'prtcorrect'          => 'qtype_stack',
+            'prtpartiallycorrect' => 'qtype_stack',
+            'prtincorrect'        => 'qtype_stack',
+        );
+    }
+}