Proyectos de Subversion Moodle

<?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/>.

/**

 * Question type class for the numerical question type.

 *

 * @package    qtype

 * @subpackage numerical

 * @copyright  1999 onwards Martin Dougiamas {@link http://moodle.com}

 * @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($CFG->dirroot . '/question/type/numerical/question.php');

/**

 * The numerical question type class.

 *

 * This class contains some special features in order to make the

 * question type embeddable within a multianswer (cloze) question

 *

 * @copyright  1999 onwards Martin Dougiamas {@link http://moodle.com}

 * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later

 */

class qtype_numerical extends question_type {

    const UNITINPUT = 0;

    const UNITRADIO = 1;

    const UNITSELECT = 2;

    const UNITNONE = 3;

    const UNITGRADED = 1;

    const UNITOPTIONAL = 0;

    const UNITGRADEDOUTOFMARK = 1;

    const UNITGRADEDOUTOFMAX = 2;

    /**

     * Validate that a string is a number formatted correctly for the current locale.

     * @param string $x a string

     * @return bool whether $x is a number that the numerical question type can interpret.

     */

    public static function is_valid_number(string $x): bool {

        $ap = new qtype_numerical_answer_processor(array());

        list($value, $unit) = $ap->apply_units($x);

        return !is_null($value) && !$unit;

    }

    public function get_question_options($question) {

        global $DB;

        parent::get_question_options($question);

        // Get the question answers and their respective tolerances

        // Note: question_numerical is an extension of the answer table rather than

        //       the question table as is usually the case for qtype

        //       specific tables.

        // If the numerical record is missing for some reason (e.g. MDL-85721), use a default tolerance.

        if (!$question->options->answers = $DB->get_records_sql(

            "

                SELECT a.*, COALESCE(n.tolerance, '0') AS tolerance

                  FROM {question_answers} a

             LEFT JOIN {question_numerical} n ON a.id = n.answer

                 WHERE a.question = ?

              ORDER BY a.id ASC

            ",

            [$question->id],

        )) {

            debugging('Error: Missing question answer for numerical question ' .

                    $question->id . '!');

        }

        $question->hints = $DB->get_records('question_hints',

                array('questionid' => $question->id), 'id ASC');

        $this->get_numerical_units($question);

        // Get_numerical_options() need to know if there are units

        // to set correctly default values.

        $this->get_numerical_options($question);

        // If units are defined we strip off the default unit from the answer, if

        // it is present. (Required for compatibility with the old code and DB).

        if ($defaultunit = $this->get_default_numerical_unit($question)) {

            foreach ($question->options->answers as $key => $val) {

                $answer = trim($val->answer);

                $length = strlen($defaultunit->unit);

                if ($length && substr($answer, -$length) == $defaultunit->unit) {

                    $question->options->answers[$key]->answer =

                            substr($answer, 0, strlen($answer)-$length);

                }

            }

        }

        return true;

    }

    public function get_numerical_units(&$question) {

        global $DB;

        if ($units = $DB->get_records('question_numerical_units',

                array('question' => $question->id), 'id ASC')) {

            $units = array_values($units);

        } else {

            $units = array();

        }

        foreach ($units as $key => $unit) {

            $units[$key]->multiplier = clean_param($unit->multiplier, PARAM_FLOAT);

        }

        $question->options->units = $units;

        return true;

    }

    public function get_default_numerical_unit($question) {

        if (isset($question->options->units[0])) {

            foreach ($question->options->units as $unit) {

                if (abs($unit->multiplier - 1.0) < '1.0e-' . ini_get('precision')) {

                    return $unit;

                }

            }

        }

        return false;

    }

    public function get_numerical_options($question) {

        global $DB;

        if (!$options = $DB->get_record('question_numerical_options',

                array('question' => $question->id))) {

            // Old question, set defaults.

            $question->options->unitgradingtype = 0;

            $question->options->unitpenalty = 0.1;

            if ($defaultunit = $this->get_default_numerical_unit($question)) {

                $question->options->showunits = self::UNITINPUT;

            } else {

                $question->options->showunits = self::UNITNONE;

            }

            $question->options->unitsleft = 0;

        } else {

            $question->options->unitgradingtype = $options->unitgradingtype;

            $question->options->unitpenalty = $options->unitpenalty;

            $question->options->showunits = $options->showunits;

            $question->options->unitsleft = $options->unitsleft;

        }

        return true;

    }

    public function save_defaults_for_new_questions(stdClass $fromform): void {

        parent::save_defaults_for_new_questions($fromform);

        $this->set_default_value('unitrole', $fromform->unitrole);

        $this->set_default_value('unitpenalty', $fromform->unitpenalty);

        $this->set_default_value('unitgradingtypes', $fromform->unitgradingtypes);

        $this->set_default_value('multichoicedisplay', $fromform->multichoicedisplay);

        $this->set_default_value('unitsleft', $fromform->unitsleft);

    }

    /**

     * Save the units and the answers associated with this question.

     */

    public function save_question_options($question) {

        global $DB;

        $context = $question->context;

        // Get old versions of the objects.

        $oldanswers = $DB->get_records('question_answers',

                array('question' => $question->id), 'id ASC');

        $oldoptions = $DB->get_records('question_numerical',

                array('question' => $question->id), 'answer ASC');

        // Save the units.

        $result = $this->save_units($question);

        if (isset($result->error)) {

            return $result;

        } else {

            $units = $result->units;

        }

        // Insert all the new answers.

        foreach ($question->answer as $key => $answerdata) {

            // Check for, and ingore, completely blank answer from the form.

            if (trim($answerdata) == '' && $question->fraction[$key] == 0 &&

                    html_is_blank($question->feedback[$key]['text'])) {

                continue;

            }

            // Update an existing answer if possible.

            $answer = array_shift($oldanswers);

            if (!$answer) {

                $answer = new stdClass();

                $answer->question = $question->id;

                $answer->answer = '';

                $answer->feedback = '';

                $answer->id = $DB->insert_record('question_answers', $answer);

            }

            if (trim($answerdata) === '*') {

                $answer->answer = '*';

            } else {

                $answer->answer = $this->apply_unit($answerdata, $units,

                        !empty($question->unitsleft));

                if ($answer->answer === false) {

                    $result->notice = get_string('invalidnumericanswer', 'qtype_numerical');

                }

            }

            $answer->fraction = $question->fraction[$key];

            $answer->feedback = $this->import_or_save_files($question->feedback[$key],

                    $context, 'question', 'answerfeedback', $answer->id);

            $answer->feedbackformat = $question->feedback[$key]['format'];

            $DB->update_record('question_answers', $answer);

            // Set up the options object.

            if (!$options = array_shift($oldoptions)) {

                $options = new stdClass();

            }

            $options->question = $question->id;

            $options->answer   = $answer->id;

            if (trim($question->tolerance[$key]) == '') {

                $options->tolerance = '';

            } else {

                $options->tolerance = $this->apply_unit($question->tolerance[$key],

                        $units, !empty($question->unitsleft));

                if ($options->tolerance === false) {

                    $result->notice = get_string('invalidnumerictolerance', 'qtype_numerical');

                }

                $options->tolerance = (string)$options->tolerance;

            }

            if (isset($options->id)) {

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

            } else {

                $DB->insert_record('question_numerical', $options);

            }

        }

        // Delete any left over old answer records.

        $fs = get_file_storage();

        foreach ($oldanswers as $oldanswer) {

            $fs->delete_area_files($context->id, 'question', 'answerfeedback', $oldanswer->id);

            $DB->delete_records('question_answers', array('id' => $oldanswer->id));

        }

        foreach ($oldoptions as $oldoption) {

            $DB->delete_records('question_numerical', array('id' => $oldoption->id));

        }

        $result = $this->save_unit_options($question);

        if (!empty($result->error) || !empty($result->notice)) {

            return $result;

        }

        $this->save_hints($question);

        return true;

    }

    /**

     * The numerical options control the display and the grading of the unit

     * part of the numerical question and related types (calculateds)

     * Questions previous to 2.0 do not have this table as multianswer questions

     * in all versions including 2.0. The default values are set to give the same grade

     * as old question.

     *

     */

    public function save_unit_options($question) {

        global $DB;

        $result = new stdClass();

        $update = true;

        $options = $DB->get_record('question_numerical_options',

                array('question' => $question->id));

        if (!$options) {

            $options = new stdClass();

            $options->question = $question->id;

            $options->id = $DB->insert_record('question_numerical_options', $options);

        }

        if (isset($question->unitpenalty)) {

            $options->unitpenalty = $question->unitpenalty;

        } else {

            // Either an old question or a close question type.

            $options->unitpenalty = 1;

        }

        $options->unitgradingtype = 0;

        if (isset($question->unitrole)) {

            // Saving the editing form.

            $options->showunits = $question->unitrole;

            if ($question->unitrole == self::UNITGRADED) {

                $options->unitgradingtype = $question->unitgradingtypes;

                $options->showunits = $question->multichoicedisplay;

            }

        } else if (isset($question->showunits)) {

            // Updated import, e.g. Moodle XML.

            $options->showunits = $question->showunits;

            if (isset($question->unitgradingtype)) {

                $options->unitgradingtype = $question->unitgradingtype;

            }

        } else {

            // Legacy import.

            if ($defaultunit = $this->get_default_numerical_unit($question)) {

                $options->showunits = self::UNITINPUT;

            } else {

                $options->showunits = self::UNITNONE;

            }

        }

        $options->unitsleft = !empty($question->unitsleft);

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

        // Report any problems.

        if (!empty($result->notice)) {

            return $result;

        }

        return true;

    }

    public function save_units($question) {

        global $DB;

        $result = new stdClass();

        // Delete the units previously saved for this question.

        $DB->delete_records('question_numerical_units', array('question' => $question->id));

        // Nothing to do.

        if (!isset($question->multiplier)) {

            $result->units = array();

            return $result;

        }

        // Save the new units.

        $units = array();

        $unitalreadyinsert = array();

        foreach ($question->multiplier as $i => $multiplier) {

            // Discard any unit which doesn't specify the unit or the multiplier.

            if (!empty($question->multiplier[$i]) && !empty($question->unit[$i]) &&

                    !array_key_exists($question->unit[$i], $unitalreadyinsert)) {

                $unitalreadyinsert[$question->unit[$i]] = 1;

                $units[$i] = new stdClass();

                $units[$i]->question = $question->id;

                $units[$i]->multiplier = $this->apply_unit($question->multiplier[$i],

                        array(), false);

                $units[$i]->unit = $question->unit[$i];

                $DB->insert_record('question_numerical_units', $units[$i]);

            }

        }

        unset($question->multiplier, $question->unit);

        $result->units = &$units;

        return $result;

    }

    protected function initialise_question_instance(question_definition $question, $questiondata) {

        parent::initialise_question_instance($question, $questiondata);

        $this->initialise_numerical_answers($question, $questiondata);

        $question->unitdisplay = $questiondata->options->showunits;

        $question->unitgradingtype = $questiondata->options->unitgradingtype;

        $question->unitpenalty = $questiondata->options->unitpenalty;

        $question->unitsleft = $questiondata->options->unitsleft;

        $question->ap = $this->make_answer_processor($questiondata->options->units,

                $questiondata->options->unitsleft);

    }

    public function initialise_numerical_answers(question_definition $question, $questiondata) {

        $question->answers = array();

        if (empty($questiondata->options->answers)) {

            return;

        }

        foreach ($questiondata->options->answers as $a) {

            $question->answers[$a->id] = new qtype_numerical_answer($a->id, $a->answer,

                    $a->fraction, $a->feedback, $a->feedbackformat, $a->tolerance);

        }

    }

    public function make_answer_processor($units, $unitsleft) {

        if (empty($units)) {

            return new qtype_numerical_answer_processor(array());

        }

        $cleanedunits = array();

        foreach ($units as $unit) {

            $cleanedunits[$unit->unit] = $unit->multiplier;

        }

        return new qtype_numerical_answer_processor($cleanedunits, $unitsleft);

    }

    public function delete_question($questionid, $contextid) {

        global $DB;

        $DB->delete_records('question_numerical', array('question' => $questionid));

        $DB->delete_records('question_numerical_options', array('question' => $questionid));

        $DB->delete_records('question_numerical_units', array('question' => $questionid));

        parent::delete_question($questionid, $contextid);

    }

    public function get_random_guess_score($questiondata) {

        foreach ($questiondata->options->answers as $aid => $answer) {

            if ('*' == trim($answer->answer)) {

                return max($answer->fraction - $questiondata->options->unitpenalty, 0);

            }

        }

        return 0;

    }

    /**

     * Add a unit to a response for display.

     * @param object $questiondata the data defining the quetsion.

     * @param string $answer a response.

     * @param object $unit a unit. If null, {@link get_default_numerical_unit()}

     * is used.

     */

    public function add_unit($questiondata, $answer, $unit = null) {

        if (is_null($unit)) {

            $unit = $this->get_default_numerical_unit($questiondata);

        }

        if (!$unit) {

            return $answer;

        }

        if (!empty($questiondata->options->unitsleft)) {

            return $unit->unit . ' ' . $answer;

        } else {

            return $answer . ' ' . $unit->unit;

        }

    }

    public function get_possible_responses($questiondata) {

        $responses = array();

        $unit = $this->get_default_numerical_unit($questiondata);

        $starfound = false;

        foreach ($questiondata->options->answers as $aid => $answer) {

            $responseclass = $answer->answer;

            if ($responseclass === '*') {

                $starfound = true;

            } else {

                $responseclass = $this->add_unit($questiondata, $responseclass, $unit);

                $ans = new qtype_numerical_answer($answer->id, $answer->answer, $answer->fraction,

                        $answer->feedback, $answer->feedbackformat, $answer->tolerance);

                list($min, $max) = $ans->get_tolerance_interval();

                $responseclass .= " ({$min}..{$max})";

            }

            $responses[$aid] = new question_possible_response($responseclass,

                    $answer->fraction);

        }

        if (!$starfound) {

            $responses[0] = new question_possible_response(

                    get_string('didnotmatchanyanswer', 'question'), 0);

        }

        $responses[null] = question_possible_response::no_response();

        return array($questiondata->id => $responses);

    }

    /**

     * Checks if the $rawresponse has a unit and applys it if appropriate.

     *

     * @param string $rawresponse  The response string to be converted to a float.

     * @param array $units         An array with the defined units, where the

     *                             unit is the key and the multiplier the value.

     * @return float               The rawresponse with the unit taken into

     *                             account as a float.

     */

    public function apply_unit($rawresponse, $units, $unitsleft) {

        $ap = $this->make_answer_processor($units, $unitsleft);

        list($value, $unit, $multiplier) = $ap->apply_units($rawresponse);

        if (!is_null($multiplier)) {

            $value *= $multiplier;

        }

        return $value;

    }

    public function move_files($questionid, $oldcontextid, $newcontextid) {

        $fs = get_file_storage();

        parent::move_files($questionid, $oldcontextid, $newcontextid);

        $this->move_files_in_answers($questionid, $oldcontextid, $newcontextid);

        $this->move_files_in_hints($questionid, $oldcontextid, $newcontextid);

    }

    protected function delete_files($questionid, $contextid) {

        $fs = get_file_storage();

        parent::delete_files($questionid, $contextid);

        $this->delete_files_in_answers($questionid, $contextid);

        $this->delete_files_in_hints($questionid, $contextid);

    }

}

/**

 * This class processes numbers with units.

 *

 * @copyright 2010 The Open University

 * @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later

 */

class qtype_numerical_answer_processor {

    /** @var array unit name => multiplier. */

    protected $units;

    /** @var string character used as decimal point. */

    protected $decsep;

    /** @var string character used as thousands separator. */

    protected $thousandssep;

    /** @var boolean whether the units come before or after the number. */

    protected $unitsbefore;

    protected $regex = null;

    public function __construct($units, $unitsbefore = false, $decsep = null,

            $thousandssep = null) {

        if (is_null($decsep)) {

            $decsep = get_string('decsep', 'langconfig');

        }

        $this->decsep = $decsep;

        if (is_null($thousandssep)) {

            $thousandssep = get_string('thousandssep', 'langconfig');

        }

        $this->thousandssep = $thousandssep;

        $this->units = $units;

        $this->unitsbefore = $unitsbefore;

    }

    /**

     * Set the decimal point and thousands separator character that should be used.

     * @param string $decsep

     * @param string $thousandssep

     */

    public function set_characters($decsep, $thousandssep) {

        $this->decsep = $decsep;

        $this->thousandssep = $thousandssep;

        $this->regex = null;

    }

    /** @return string the decimal point character used. */

    public function get_point() {

        return $this->decsep;

    }

    /** @return string the thousands separator character used. */

    public function get_separator() {

        return $this->thousandssep;

    }

    /**

     * @return bool If the student's response contains a '.' or a ',' that

     * matches the thousands separator in the current locale. In this case, the

     * parsing in apply_unit can give a result that the student did not expect.

     */

    public function contains_thousands_seaparator($value) {

        if (!in_array($this->thousandssep, array('.', ','))) {

            return false;

        }

        return strpos($value, $this->thousandssep) !== false;

    }

    /**

     * Create the regular expression that {@link parse_response()} requires.

     * @return string

     */

    protected function build_regex() {

        if (!is_null($this->regex)) {

            return $this->regex;

        }

        $decsep = preg_quote($this->decsep, '/');

        $thousandssep = preg_quote($this->thousandssep, '/');

        $beforepointre = '([+-]?[' . $thousandssep . '\d]*)';

        $decimalsre = $decsep . '(\d*)';

        $exponentre = '(?:e|E|(?:x|\*|×)10(?:\^|\*\*))([+-]?\d+)';

        $numberbit = "{$beforepointre}(?:{$decimalsre})?(?:{$exponentre})?";

        if ($this->unitsbefore) {

            $this->regex = "/{$numberbit}$/";

        } else {

            $this->regex = "/^{$numberbit}/";

        }

        return $this->regex;

    }

    /**

     * This method can be used for more locale-strict parsing of repsonses. At the

     * moment we don't use it, and instead use the more lax parsing in apply_units.

     * This is just a note that this funciton was used in the past, so if you are

     * intersted, look through version control history.

     *

     * Take a string which is a number with or without a decimal point and exponent,

     * and possibly followed by one of the units, and split it into bits.

     * @param string $response a value, optionally with a unit.

     * @return array four strings (some of which may be blank) the digits before

     * and after the decimal point, the exponent, and the unit. All four will be

     * null if the response cannot be parsed.

     */

    protected function parse_response($response) {

        if (!preg_match($this->build_regex(), $response, $matches)) {

            return array(null, null, null, null);

        }

        $matches += array('', '', '', ''); // Fill in any missing matches.

        list($matchedpart, $beforepoint, $decimals, $exponent) = $matches;

        // Strip out thousands separators.

        $beforepoint = str_replace($this->thousandssep, '', $beforepoint);

        // Must be either something before, or something after the decimal point.

        // (The only way to do this in the regex would make it much more complicated.)

        if ($beforepoint === '' && $decimals === '') {

            return array(null, null, null, null);

        }

        if ($this->unitsbefore) {

            $unit = substr($response, 0, -strlen($matchedpart));

        } else {

            $unit = substr($response, strlen($matchedpart));

        }

        $unit = trim($unit);

        return array($beforepoint, $decimals, $exponent, $unit);

    }

    /**

     * Takes a number in almost any localised form, and possibly with a unit

     * after it. It separates off the unit, if present, and converts to the

     * default unit, by using the given unit multiplier.

     *

     * @param string $response a value, optionally with a unit.

     * @return array(numeric, string, multiplier) the value with the unit stripped, and normalised

     *      by the unit multiplier, if any, and the unit string, for reference.

     */

    public function apply_units($response, $separateunit = null): array {

        if ($response === null || trim($response) === '') {

            return [null, null, null];

        }

        // Strip spaces (which may be thousands separators) and change other forms

        // of writing e to e.

        $response = str_replace(' ', '', $response);

        $response = preg_replace('~(?:e|E|(?:x|\*|×)10(?:\^|\*\*))([+-]?\d+)~', 'e$1', $response);

        // If a . is present or there are multiple , (i.e. 2,456,789 ) assume ,

        // is a thouseands separator, and strip it, else assume it is a decimal

        // separator, and change it to ..

        if (strpos($response, '.') !== false || substr_count($response, ',') > 1) {

            $response = str_replace(',', '', $response);

        } else {

            $response = str_replace([$this->thousandssep, $this->decsep, ','], ['', '.', '.'], $response);

        }

        $regex = '[+-]?(?:\d+(?:\\.\d*)?|\\.\d+)(?:e[-+]?\d+)?';

        if ($this->unitsbefore) {

            $regex = "/{$regex}$/";

        } else {

            $regex = "/^{$regex}/";

        }

        if (!preg_match($regex, $response, $matches)) {

            return array(null, null, null);

        }

        $numberstring = $matches[0];

        if ($this->unitsbefore) {

            // Substr returns false when it means '', so cast back to string.

            $unit = (string) substr($response, 0, -strlen($numberstring));

        } else {

            $unit = (string) substr($response, strlen($numberstring));

        }

        if (!is_null($separateunit)) {

            $unit = $separateunit;

        }

        if ($this->is_known_unit($unit)) {

            $multiplier = 1 / $this->units[$unit];

        } else {

            $multiplier = null;

        }

        return array($numberstring + 0, $unit, $multiplier); // The + 0 is to convert to number.

    }

    /**

     * @return string the default unit.

     */

    public function get_default_unit() {

        reset($this->units);

        return key($this->units);

    }

    /**

     * @param string $answer a response.

     * @param string $unit a unit.

     */

    public function add_unit($answer, $unit = null) {

        if (is_null($unit)) {

            $unit = $this->get_default_unit();

        }

        if (!$unit) {

            return $answer;

        }

        if ($this->unitsbefore) {

            return $unit . ' ' . $answer;

        } else {

            return $answer . ' ' . $unit;

        }

    }

    /**

     * Is this unit recognised.

     * @param string $unit the unit

     * @return bool whether this is a unit we recognise.

     */

    public function is_known_unit($unit) {

        return array_key_exists($unit, $this->units);

    }

    /**

     * Whether the units go before or after the number.

     * @return true = before, false = after.

     */

    public function are_units_before() {

        return $this->unitsbefore;

    }

    /**

     * Get the units as an array suitably for passing to html_writer::select.

     * @return array of unit choices.

     */

    public function get_unit_options() {

        $options = array();

        foreach ($this->units as $unit => $notused) {

            $options[$unit] = $unit;

        }

        return $options;

    }

}