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See Release Notes

  • Bug fixes for general core bugs in 4.2.x will end 22 April 2024 (12 months).
  • Bug fixes for security issues in 4.2.x will end 7 October 2024 (18 months).
  • PHP version: minimum PHP 8.0.0 Note: minimum PHP version has increased since Moodle 4.1. PHP 8.1.x is supported too.
<?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/>.

/**
< * Upgrade library code for the calculated question type. < * < * @package qtype < * @subpackage calculated < * @copyright 2011 The Open University < * @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later < */ < < < defined('MOODLE_INTERNAL') || die(); < < < /**
* Class for converting attempt data for calculated questions when upgrading * attempts to the new question engine. * * This class is used by the code in question/engine/upgrade/upgradelib.php. *
> * @package qtype_calculated
* @copyright 2011 The Open University * @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later */ class qtype_calculated_qe2_attempt_updater extends question_qtype_attempt_updater { protected $selecteditem = null; /** @var array variable name => value */
< protected $values;
> protected $values = [];
/** @var array variable names wrapped in {...}. Used by {@link substitute_values()}. */
< protected $search;
> protected $search = [];
/** * @var array variable values, with negative numbers wrapped in (...). * Used by {@link substitute_values()}. */
< protected $safevalue;
> protected $safevalue = [];
/** * @var array variable values, with negative numbers wrapped in (...). * Used by {@link substitute_values()}. */
< protected $prettyvalue;
> protected $prettyvalue = [];
public function question_summary() { return ''; // Done later, after we know which dataset is used. } public function right_answer() { foreach ($this->question->options->answers as $ans) { if ($ans->fraction > 0.999) { $right = $this->calculate($ans->answer); if (empty($this->question->options->units)) { return $right; } $unit = reset($this->question->options->units); $unit = $unit->unit; if (!empty($this->question->options->unitsleft)) { return $unit . ' ' . $right; } else { return $right . ' ' . $unit; } } } } protected function parse_response($state) { if (strpos($state->answer, '-') < 7) { // Broken state, skip it. throw new coding_exception("Brokes state {$state->id} for calculated question {$state->question}. (It did not specify a dataset."); }
< list($datasetbit, $realanswer) = explode('-', $state->answer, 2);
> [$datasetbit, $realanswer] = explode('-', $state->answer, 2);
$selecteditem = substr($datasetbit, 7); if (is_null($this->selecteditem)) { $this->load_dataset($selecteditem); } else if ($this->selecteditem != $selecteditem) { $this->logger->log_assumption("Different states for calculated question {$state->question} used different dataset items. Ignoring the change in state {$state->id} and coninuting to use item {$this->selecteditem}."); } if (!$realanswer) {
< return array('', '');
> return ['', ''];
} if (strpos($realanswer, '|||||') === false) { $answer = $realanswer; $unit = ''; } else {
< list($answer, $unit) = explode('|||||', $realanswer, 2);
> [$answer, $unit] = explode('|||||', $realanswer, 2);
}
< return array($answer, $unit);
> return [$answer, $unit];
} public function response_summary($state) {
< list($answer, $unit) = $this->parse_response($state);
> [$answer, $unit] = $this->parse_response($state);
if (empty($answer) && empty($unit)) { $resp = null; } else { $resp = $answer; } if (!empty($unit)) { if (!empty($this->question->options->unitsleft)) { $resp = trim($unit . ' ' . $resp); } else { $resp = trim($resp . ' ' . $unit); } } return $resp; } public function was_answered($state) { return !empty($state->answer); } public function set_first_step_data_elements($state, &$data) { $this->parse_response($state); $this->updater->qa->questionsummary = $this->to_text( $this->replace_expressions_in_text($this->question->questiontext)); $this->updater->qa->rightanswer = $this->right_answer($this->question); foreach ($this->values as $name => $value) { $data['_var_' . $name] = $value; } $data['_separators'] = '.$,'; } public function supply_missing_first_step_data(&$data) { $data['_separators'] = '.$,'; } public function set_data_elements_for_step($state, &$data) { if (empty($state->answer)) { return; }
< list($answer, $unit) = $this->parse_response($state); < if (!empty($this->question->options->showunits) && < $this->question->options->showunits == 1) {
> [$answer, $unit] = $this->parse_response($state); > if ( > !empty($this->question->options->showunits) && > $this->question->options->showunits == 1 > ) {
// Multichoice units. $data['answer'] = $answer; $data['unit'] = $unit; } else if (!empty($this->question->options->unitsleft)) { if (!empty($unit)) { $data['answer'] = $unit . ' ' . $answer; } else { $data['answer'] = $answer; } } else { if (!empty($unit)) { $data['answer'] = $answer . ' ' . $unit; } else { $data['answer'] = $answer; } } } public function load_dataset($selecteditem) { $this->selecteditem = $selecteditem; $this->updater->qa->variant = $selecteditem; $this->values = $this->qeupdater->load_dataset( $this->question->id, $selecteditem); // Prepare an array for {@link substitute_values()}.
< $this->search = array(); < $this->safevalue = array(); < $this->prettyvalue = array();
> $this->search = []; > $this->safevalue = []; > $this->prettyvalue = [];
foreach ($this->values as $name => $value) { if (!is_numeric($value)) { $a = new stdClass(); $a->name = '{' . $name . '}'; $a->value = $value; throw new moodle_exception('notvalidnumber', 'qtype_calculated', '', $a); } $this->search[] = '{' . $name . '}'; $this->safevalue[] = '(' . $value . ')'; $this->prettyvalue[] = $this->format_float($value); } } /** * This function should be identical to * {@link qtype_calculated_variable_substituter::format_float()}. Except that * we do not try to do locale-aware replacement of the decimal point. * * Having to copy it here is a pain, but it is the standard rule about not * using library code (which may change in future) in upgrade code, which * exists at a point in time. * * Display a float properly formatted with a certain number of decimal places. * @param number $x the number to format * @param int $length restrict to this many decimal places or significant * figures. If null, the number is not rounded. * @param int format 1 => decimalformat, 2 => significantfigures. * @return string formtted number. */ public function format_float($x, $length = null, $format = null) { if (!is_null($length) && !is_null($format)) { if ($format == 1) { // Decimal places. $x = sprintf('%.' . $length . 'F', $x); } else if ($format == 2) { // Significant figures. $x = sprintf('%.' . $length . 'g', $x); } } return $x; } /** * Evaluate an expression using the variable values. * @param string $expression the expression. A PHP expression with placeholders * like {a} for where the variables need to go. * @return float the computed result. */ public function calculate($expression) { return $this->calculate_raw($this->substitute_values_for_eval($expression)); } /** * Evaluate an expression after the variable values have been substituted. * @param string $expression the expression. A PHP expression with placeholders * like {a} for where the variables need to go. * @return float the computed result. */ protected function calculate_raw($expression) { try { // In older PHP versions this this is a way to validate code passed to eval. // The trick came from http://php.net/manual/en/function.eval.php. if (@eval('return true; $result = ' . $expression . ';')) { return eval('return ' . $expression . ';'); } } catch (Throwable $e) { // PHP7 and later now throws ParseException and friends from eval(), // which is much better. } // In either case of an invalid $expression, we end here. return '[Invalid expression ' . $expression . ']'; } /** * Substitute variable placehodlers like {a} with their value wrapped in (). * @param string $expression the expression. A PHP expression with placeholders * like {a} for where the variables need to go. * @return string the expression with each placeholder replaced by the * corresponding value. */ protected function substitute_values_for_eval($expression) {
< return str_replace($this->search, $this->safevalue, $expression);
> return str_replace($this->search, $this->safevalue, $expression ?? '');
} /** * Substitute variable placehodlers like {a} with their value without wrapping * the value in anything. * @param string $text some content with placeholders * like {a} for where the variables need to go. * @return string the expression with each placeholder replaced by the * corresponding value. */ protected function substitute_values_pretty($text) {
< return str_replace($this->search, $this->prettyvalue, $text);
> return str_replace($this->search, $this->prettyvalue, $text ?? '');
} /** * Replace any embedded variables (like {a}) or formulae (like {={a} + {b}}) * in some text with the corresponding values. * @param string $text the text to process. * @return string the text with values substituted. */ public function replace_expressions_in_text($text, $length = null, $format = null) {
> if ($text === null || $text === '') { $vs = $this; // Can't see to use $this in a PHP closure. > return $text; $text = preg_replace_callback('~\{=([^{}]*(?:\{[^{}]+}[^{}]*)*)}~', > }
< $text = preg_replace_callback('~\{=([^{}]*(?:\{[^{}]+}[^{}]*)*)}~',
> $text = preg_replace_callback( > '~\{=([^{}]*(?:\{[^{}]+}[^{}]*)*)}~',
return $vs->format_float($vs->calculate($matches[1]), $length, $format);
< }, $text);
> }, > $text > );
return $this->substitute_values_pretty($text); } }