questiontype.php

<?php
// This file is part of Stack - http://stack.maths.ed.ac.uk/
//
// Stack 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.
//
// Stack 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 Stack.  If not, see <http://www.gnu.org/licenses/>.

/**
 * Question type class for the Stack question type.
 *
 * @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();

require_once($CFG->libdir . '/questionlib.php');
require_once(__DIR__ . '/stack/input/factory.class.php');
require_once(__DIR__ . '/stack/answertest/controller.class.php');
require_once(__DIR__ . '/stack/cas/keyval.class.php');
require_once(__DIR__ . '/stack/cas/castext2/castext2_evaluatable.class.php');
require_once(__DIR__ . '/stack/cas/castext2/castext2_static_replacer.class.php');
require_once(__DIR__ . '/stack/questiontest.php');
require_once(__DIR__ . '/stack/prt.class.php');
require_once(__DIR__ . '/stack/potentialresponsetreestate.class.php');
require_once(__DIR__ . '/stack/prt.class.php');
require_once(__DIR__ . '/stack/graphlayout/graph.php');
require_once(__DIR__ . '/lang/multilang.php');
require_once(__DIR__ . '/stack/prt.class.php');


/**
 * Stack question type class.
 *
 * @copyright  2012 The Open University
 * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
 */
class qtype_stack extends question_type {

    /** @var int array key into the results of get_input_names_from_question_text for the count of input placeholders. */
    const INPUTS = 0;
    /** @var int array key into the results of get_input_names_from_question_text for the count of validation placeholders. */
    const VALIDATIONS = 1;

    /** @var int the CAS seed using during validation. */
    protected $seed = 1;

    /** @var stack_options the CAS options using during validation. */
    protected $options;

    /**
     * @var array prt name => stack_abstract_graph caches the result of
     * {@link get_prt_graph()}.
     */
    protected $prtgraph = array();

    public function save_question($question, $fromform) {

        if (!empty($fromform->fixdollars)) {
            $this->fix_dollars_in_form_data($fromform);
        }

        $fromform->penalty = stack_utils::fix_approximate_thirds($fromform->penalty);

        // If this questions is being derived from another one (either duplicate in any
        // Moodle version, or editing making a new version in Moodle 4.0+) then we need
        // to get the deployed variants and question tests, so they can be copied too.
        // The property used seems to be the reliable way to get the old question id.
        if (isset($question->options->questionid) && $question->options->questionid) {
            $fromform->deployedseeds = $this->get_question_deployed_seeds($question->options->questionid);
            $fromform->testcases = $this->load_question_tests($question->options->questionid);
        }

        $new = parent::save_question($question, $fromform);

        return $new;
    }

    /**
     * Replace any $...$ and $$...$$ delimiters in the question text from the
     * form with the recommended delimiters.
     * @param object $fromform the data from the form.
     */
    protected function fix_dollars_in_form_data($fromform) {
        $questionfields = array('questiontext', 'generalfeedback', 'specificfeedback',
                'prtcorrect', 'prtpartiallycorrect', 'prtincorrect', 'questiondescription');
        foreach ($questionfields as $field) {
            $fromform->{$field}['text'] = stack_maths::replace_dollars($fromform->{$field}['text']);
        }
        $fromform->questionnote = stack_maths::replace_dollars($fromform->questionnote);

        $prtnames = array_keys($this->get_prt_names_from_question($fromform->questiontext['text'],
                $fromform->specificfeedback['text']));
        foreach ($prtnames as $prt) {
            foreach ($fromform->{$prt . 'truefeedback'} as &$feedback) {
                $feedback['text'] = stack_maths::replace_dollars($feedback['text']);
            }

            foreach ($fromform->{$prt . 'falsefeedback'} as &$feedback) {
                $feedback['text'] = stack_maths::replace_dollars($feedback['text']);
            }
        }

        foreach ($fromform->hint as &$hint) {
            $hint['text'] = stack_maths::replace_dollars($hint['text']);
        }
    }

    public function save_question_options($fromform) {
        global $DB;
        $context = $fromform->context;

        parent::save_question_options($fromform);

        $options = $DB->get_record('qtype_stack_options', array('questionid' => $fromform->id));
        if (!$options) {
            $options = new stdClass();
            $options->questionid = $fromform->id;
            $options->questionvariables = '';
            $options->questionnote = '';
            $options->questiondescription = '';
            $options->specificfeedback = '';
            $options->prtcorrect = '';
            $options->prtpartiallycorrect = '';
            $options->prtincorrect = '';
            $options->stackversion = get_config('qtype_stack', 'version');
            $options->id = $DB->insert_record('qtype_stack_options', $options);
        }

        $options->stackversion              = $fromform->stackversion;
        $options->questionvariables         = $fromform->questionvariables;
        $options->specificfeedback          = $this->import_or_save_files($fromform->specificfeedback,
                    $context, 'qtype_stack', 'specificfeedback', $fromform->id);
        $options->specificfeedbackformat    = $fromform->specificfeedback['format'];
        $options->questionnote              = $fromform->questionnote;
        $options->questiondescription       = $this->import_or_save_files($fromform->questiondescription,
            $context, 'qtype_stack', 'questiondescription', $fromform->id);
        $options->questiondescriptionformat = $fromform->questiondescription['format'];
        $options->questionsimplify          = $fromform->questionsimplify;
        $options->assumepositive            = $fromform->assumepositive;
        $options->assumereal                = $fromform->assumereal;
        $options->prtcorrect                = $this->import_or_save_files($fromform->prtcorrect,
                    $context, 'qtype_stack', 'prtcorrect', $fromform->id);
        $options->prtcorrectformat          = $fromform->prtcorrect['format'];
        $options->prtpartiallycorrect       = $this->import_or_save_files($fromform->prtpartiallycorrect,
                    $context, 'qtype_stack', 'prtpartiallycorrect', $fromform->id);
        $options->prtpartiallycorrectformat = $fromform->prtpartiallycorrect['format'];
        $options->prtincorrect              = $this->import_or_save_files($fromform->prtincorrect,
                    $context, 'qtype_stack', 'prtincorrect', $fromform->id);
        $options->prtincorrectformat        = $fromform->prtincorrect['format'];
        $options->decimals                  = $fromform->decimals;
        $options->multiplicationsign        = $fromform->multiplicationsign;
        $options->sqrtsign                  = $fromform->sqrtsign;
        $options->complexno                 = $fromform->complexno;
        $options->inversetrig               = $fromform->inversetrig;
        $options->logicsymbol               = $fromform->logicsymbol;
        $options->matrixparens              = $fromform->matrixparens;
        $options->variantsselectionseed     = $fromform->variantsselectionseed;

        // We will not have the values for this.
        $options->compiledcache             = '{}';

        $DB->update_record('qtype_stack_options', $options);

        $inputnames = array_keys($this->get_input_names_from_question_text_lang($fromform->questiontext));
        $inputs = $DB->get_records('qtype_stack_inputs',
                array('questionid' => $fromform->id), '', 'name, id, questionid');
        $questionhasinputs = false;
        foreach ($inputnames as $inputname) {
            if (array_key_exists($inputname, $inputs)) {
                $input = $inputs[$inputname];
                unset($inputs[$inputname]);
            } else {
                $input = new stdClass();
                $input->questionid = $fromform->id;
                $input->name       = $inputname;
                $input->options    = '';
                $input->id = $DB->insert_record('qtype_stack_inputs', $input);
            }

            $input->type               = $fromform->{$inputname . 'type'};
            $input->tans               = $fromform->{$inputname . 'modelans'};
            $input->boxsize            = $fromform->{$inputname . 'boxsize'};
            // TODO: remove this when we remove strictsyntax from the DB.
            $input->strictsyntax       = true;
            $input->insertstars        = $fromform->{$inputname . 'insertstars'};
            $input->syntaxhint         = $fromform->{$inputname . 'syntaxhint'};
            $input->syntaxattribute    = $fromform->{$inputname . 'syntaxattribute'};
            $input->forbidwords        = $fromform->{$inputname . 'forbidwords'};