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See Release Notes

  • Bug fixes for general core bugs in 3.10.x will end 8 November 2021 (12 months).
  • Bug fixes for security issues in 3.10.x will end 9 May 2022 (18 months).
  • PHP version: minimum PHP 7.2.0 Note: minimum PHP version has increased since Moodle 3.8. PHP 7.3.x and 7.4.x are 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/>.

/**
 * Numerical question definition class.
 *
 * @package    qtype
 * @subpackage numerical
 * @copyright  2009 The Open University
 * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
 */


defined('MOODLE_INTERNAL') || die();

require_once($CFG->dirroot . '/question/type/questionbase.php');

/**
 * Represents a numerical question.
 *
 * @copyright  2009 The Open University
 * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
 */
class qtype_numerical_question extends question_graded_automatically {
    /** @var array of question_answer. */
    public $answers = array();

    /** @var int one of the constants UNITNONE, UNITRADIO, UNITSELECT or UNITINPUT. */
    public $unitdisplay;
    /** @var int one of the constants UNITGRADEDOUTOFMARK or UNITGRADEDOUTOFMAX. */
    public $unitgradingtype;
    /** @var number the penalty for a missing or unrecognised unit. */
    public $unitpenalty;
    /** @var boolean whether the units come before or after the number */
    public $unitsleft;
    /** @var qtype_numerical_answer_processor */
    public $ap;

    public function get_expected_data() {
        $expected = array('answer' => PARAM_RAW_TRIMMED);
        if ($this->has_separate_unit_field()) {
            $expected['unit'] = PARAM_RAW_TRIMMED;
        }
        return $expected;
    }

    public function has_separate_unit_field() {
        return $this->unitdisplay == qtype_numerical::UNITRADIO ||
                $this->unitdisplay == qtype_numerical::UNITSELECT;
    }

    public function start_attempt(question_attempt_step $step, $variant) {
        $step->set_qt_var('_separators',
                $this->ap->get_point() . '$' . $this->ap->get_separator());
    }

    public function apply_attempt_state(question_attempt_step $step) {
        list($point, $separator) = explode('$', $step->get_qt_var('_separators'));
                $this->ap->set_characters($point, $separator);
    }

    public function summarise_response(array $response) {
        if (isset($response['answer'])) {
            $resp = $response['answer'];
        } else {
            $resp = null;
        }

        if ($this->has_separate_unit_field() && !empty($response['unit'])) {
            $resp = $this->ap->add_unit($resp, $response['unit']);
        }

        return $resp;
    }

    public function un_summarise_response(string $summary) {
        if ($this->has_separate_unit_field()) {
            throw new coding_exception('Sorry, but at the moment un_summarise_response cannot handle the
                has_separate_unit_field case for numerical questions.
                    If you need this, you will have to implement it yourself.');
        }

        if (!empty($summary)) {
            return ['answer' => $summary];
        } else {
            return [];
        }
    }

    public function is_gradable_response(array $response) {
        return array_key_exists('answer', $response) &&
                ($response['answer'] || $response['answer'] === '0' || $response['answer'] === 0);
    }

    public function is_complete_response(array $response) {
        if (!$this->is_gradable_response($response)) {
            return false;
        }

        list($value, $unit) = $this->ap->apply_units($response['answer']);
        if (is_null($value)) {
            return false;
        }

        if ($this->unitdisplay != qtype_numerical::UNITINPUT && $unit) {
            return false;
        }

        if ($this->has_separate_unit_field() && empty($response['unit'])) {
            return false;
        }

        if ($this->ap->contains_thousands_seaparator($response['answer'])) {
            return false;
        }

        return true;
    }

    public function get_validation_error(array $response) {
        if (!$this->is_gradable_response($response)) {
            return get_string('pleaseenterananswer', 'qtype_numerical');
        }

        list($value, $unit) = $this->ap->apply_units($response['answer']);
        if (is_null($value)) {
            return get_string('invalidnumber', 'qtype_numerical');
        }

        if ($this->unitdisplay != qtype_numerical::UNITINPUT && $unit) {
            return get_string('invalidnumbernounit', 'qtype_numerical');
        }

        if ($this->has_separate_unit_field() && empty($response['unit'])) {
            return get_string('unitnotselected', 'qtype_numerical');
        }

        if ($this->ap->contains_thousands_seaparator($response['answer'])) {
            return get_string('pleaseenteranswerwithoutthousandssep', 'qtype_numerical',
                    $this->ap->get_separator());
        }

        return '';
    }

    public function is_same_response(array $prevresponse, array $newresponse) {
        if (!question_utils::arrays_same_at_key_missing_is_blank(
                $prevresponse, $newresponse, 'answer')) {
            return false;
        }

        if ($this->has_separate_unit_field()) {
            return question_utils::arrays_same_at_key_missing_is_blank(
                $prevresponse, $newresponse, 'unit');
        }

        return true;
    }

    public function get_correct_response() {
        $answer = $this->get_correct_answer();
        if (!$answer) {
            return array();
        }

        $response = array('answer' => str_replace('.', $this->ap->get_point(), $answer->answer));

        if ($this->has_separate_unit_field()) {
            $response['unit'] = $this->ap->get_default_unit();
        } else if ($this->unitdisplay == qtype_numerical::UNITINPUT) {
            $response['answer'] = $this->ap->add_unit($answer->answer);
        }

        return $response;
    }

    /**
     * Get an answer that contains the feedback and fraction that should be
     * awarded for this response.
     * @param number $value the numerical value of a response.
     * @param number $multiplier for the unit the student gave, if any. When no
     *      unit was given, or an unrecognised unit was given, $multiplier will be null.
     * @return question_answer the matching answer.
     */
    public function get_matching_answer($value, $multiplier) {
        if (is_null($value) || $value === '') {
            return null;
        }

        if (!is_null($multiplier)) {
            $scaledvalue = $value * $multiplier;
        } else {
            $scaledvalue = $value;
        }
        foreach ($this->answers as $answer) {
            if ($answer->within_tolerance($scaledvalue)) {
< $answer->unitisright = !is_null($multiplier);
return $answer; } else if ($answer->within_tolerance($value)) {
< $answer->unitisright = false;
return $answer; } } return null; }
> /** public function get_correct_answer() { > * Checks if the provided $multiplier is appropriate for the unit of the given $value, foreach ($this->answers as $answer) { > * ensuring that multiplying $value by the $multiplier yields the expected $answer. $state = question_state::graded_state_for_fraction($answer->fraction); > * if ($state == question_state::$gradedright) { > * @param qtype_numerical_answer $answer The expected result when multiplying $value by the appropriate $multiplier. return $answer; > * @param float $value The provided value } > * @param float|null $multiplier The multiplier value for the unit of $value. } > * @return bool Returns true if the $multiplier is correct for the unit of $value, false otherwise. return null; > */ } > public function is_unit_right(qtype_numerical_answer $answer, float $value, ?float $multiplier): bool { > if (is_null($multiplier)) { /** > return false; * Adjust the fraction based on whether the unit was correct. > } * @param number $fraction > * @param bool $unitisright > return $answer->within_tolerance($multiplier * $value); * @return number > } */ >
public function apply_unit_penalty($fraction, $unitisright) { if ($unitisright) { return $fraction; } if ($this->unitgradingtype == qtype_numerical::UNITGRADEDOUTOFMARK) { $fraction -= $this->unitpenalty * $fraction; } else if ($this->unitgradingtype == qtype_numerical::UNITGRADEDOUTOFMAX) { $fraction -= $this->unitpenalty; } return max($fraction, 0); } public function grade_response(array $response) { if ($this->has_separate_unit_field()) { $selectedunit = $response['unit']; } else { $selectedunit = null; } list($value, $unit, $multiplier) = $this->ap->apply_units( $response['answer'], $selectedunit);
> /** @var qtype_numerical_answer $answer */
$answer = $this->get_matching_answer($value, $multiplier); if (!$answer) { return array(0, question_state::$gradedwrong); }
< $fraction = $this->apply_unit_penalty($answer->fraction, $answer->unitisright);
> $unitisright = $this->is_unit_right($answer, $value, $multiplier); > $fraction = $this->apply_unit_penalty($answer->fraction, $unitisright);
return array($fraction, question_state::graded_state_for_fraction($fraction)); } public function classify_response(array $response) { if (!$this->is_gradable_response($response)) { return array($this->id => question_classified_response::no_response()); } if ($this->has_separate_unit_field()) { $selectedunit = $response['unit']; } else { $selectedunit = null; } list($value, $unit, $multiplier) = $this->ap->apply_units($response['answer'], $selectedunit);
> /** @var qtype_numerical_answer $ans */
$ans = $this->get_matching_answer($value, $multiplier); $resp = $response['answer']; if ($this->has_separate_unit_field()) { $resp = $this->ap->add_unit($resp, $unit); } if ($value === null) { // Invalid response shown as no response (but show actual response). return array($this->id => new question_classified_response(null, $resp, 0)); } else if (!$ans) { // Does not match any answer. return array($this->id => new question_classified_response(0, $resp, 0)); }
< return array($this->id => new question_classified_response($ans->id, < $resp, < $this->apply_unit_penalty($ans->fraction, $ans->unitisright)));
> $unitisright = $this->is_unit_right($ans, $value, $multiplier); > return [ > $this->id => new question_classified_response($ans->id, $resp, $this->apply_unit_penalty($ans->fraction, $unitisright)) > ];
} public function check_file_access($qa, $options, $component, $filearea, $args, $forcedownload) { if ($component == 'question' && $filearea == 'answerfeedback') { $currentanswer = $qa->get_last_qt_var('answer'); if ($this->has_separate_unit_field()) { $selectedunit = $qa->get_last_qt_var('unit'); } else { $selectedunit = null; } list($value, $unit, $multiplier) = $this->ap->apply_units( $currentanswer, $selectedunit); $answer = $this->get_matching_answer($value, $multiplier); $answerid = reset($args); // Itemid is answer id. return $options->feedback && $answer && $answerid == $answer->id; } else if ($component == 'question' && $filearea == 'hint') { return $this->check_hint_file_access($qa, $options, $args); } else { return parent::check_file_access($qa, $options, $component, $filearea, $args, $forcedownload); } } /** * Return the question settings that define this question as structured data. * * @param question_attempt $qa the current attempt for which we are exporting the settings. * @param question_display_options $options the question display options which say which aspects of the question * should be visible. * @return mixed structure representing the question settings. In web services, this will be JSON-encoded. */ public function get_question_definition_for_external_rendering(question_attempt $qa, question_display_options $options) { // This is a partial implementation, returning only the most relevant question settings for now, // ideally, we should return as much as settings as possible (depending on the state and display options). return [ 'unitgradingtype' => $this->unitgradingtype, 'unitpenalty' => $this->unitpenalty, 'unitdisplay' => $this->unitdisplay, 'unitsleft' => $this->unitsleft, ]; } } /** * Subclass of {@link question_answer} with the extra information required by * the numerical question type. * * @copyright 2009 The Open University * @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later */ class qtype_numerical_answer extends question_answer { /** @var float allowable margin of error. */ public $tolerance; /** @var integer|string see {@link get_tolerance_interval()} for the meaning of this value. */ public $tolerancetype = 2; public function __construct($id, $answer, $fraction, $feedback, $feedbackformat, $tolerance) { parent::__construct($id, $answer, $fraction, $feedback, $feedbackformat);
< $this->tolerance = abs($tolerance);
> $this->tolerance = abs((float)$tolerance);
} public function get_tolerance_interval() { if ($this->answer === '*') { throw new coding_exception('Cannot work out tolerance interval for answer *.'); } // Smallest number that, when added to 1, is different from 1. $epsilon = pow(10, -1 * ini_get('precision')); // We need to add a tiny fraction depending on the set precision to make // the comparison work correctly, otherwise seemingly equal values can // yield false. See MDL-3225. $tolerance = abs($this->tolerance) + $epsilon; switch ($this->tolerancetype) { case 1: case 'relative': $range = abs($this->answer) * $tolerance; return array($this->answer - $range, $this->answer + $range); case 2: case 'nominal': $tolerance = $this->tolerance + $epsilon * max(abs($this->tolerance), abs($this->answer), $epsilon); return array($this->answer - $tolerance, $this->answer + $tolerance); case 3: case 'geometric': $quotient = 1 + abs($tolerance);
> if ($this->answer < 0) { return array($this->answer / $quotient, $this->answer * $quotient); > return array($this->answer * $quotient, $this->answer / $quotient); > }
default: throw new coding_exception('Unknown tolerance type ' . $this->tolerancetype); } } public function within_tolerance($value) { if ($this->answer === '*') { return true; } list($min, $max) = $this->get_tolerance_interval(); return $min <= $value && $value <= $max; } }