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<?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 multi-answer question type.** @package qtype* @subpackage multianswer* @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($CFG->dirroot . '/question/type/questiontypebase.php');require_once($CFG->dirroot . '/question/type/multichoice/question.php');require_once($CFG->dirroot . '/question/type/numerical/questiontype.php');/*** The multi-answer question type class.** @copyright 1999 onwards Martin Dougiamas {@link http://moodle.com}* @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later*/class qtype_multianswer extends question_type {/*** Generate a subquestion replacement question class.** Due to a bug, subquestions can be lost (see MDL-54724). This class exists to take* the place of those lost questions so that the system can keep working and inform* the user of the corrupted data.** @return question_automatically_gradable The replacement question class.*/public static function deleted_subquestion_replacement(): question_automatically_gradable {return new class implements question_automatically_gradable {public $qtype;public function __construct() {$this->qtype = new class() {public function name() {return 'subquestion_replacement';}};}public function is_gradable_response(array $response) {return false;}public function is_complete_response(array $response) {return false;}public function is_same_response(array $prevresponse, array $newresponse) {return false;}public function summarise_response(array $response) {return '';}public function un_summarise_response(string $summary) {return [];}public function classify_response(array $response) {return [];}public function get_validation_error(array $response) {return '';}public function grade_response(array $response) {return [];}public function get_hint($hintnumber, question_attempt $qa) {return;}public function get_right_answer_summary() {return null;}};}public function can_analyse_responses() {return false;}public function get_question_options($question) {global $DB;parent::get_question_options($question);// Get relevant data indexed by positionkey from the multianswers table.$sequence = $DB->get_field('question_multianswer', 'sequence',array('question' => $question->id), MUST_EXIST);if (empty($sequence)) {$question->options->questions = [];return true;}$wrappedquestions = $DB->get_records_list('question', 'id',explode(',', $sequence), 'id ASC');// We want an array with question ids as index and the positions as values.$sequence = array_flip(explode(',', $sequence));array_walk($sequence, function(&$val) {$val++;});// Due to a bug, questions can be lost (see MDL-54724). So we first fill the question// options with this dummy "replacement" type. These are overridden in the loop below// leaving behind only those questions which no longer exist. The renderer then looks// for this deleted type to display information to the user about the corrupted question// data.foreach ($sequence as $seq) {$question->options->questions[$seq] = (object)['qtype' => 'subquestion_replacement','defaultmark' => 1,'options' => (object)['answers' => []]];}foreach ($wrappedquestions as $wrapped) {question_bank::get_qtype($wrapped->qtype)->get_question_options($wrapped);// For wrapped questions the maxgrade is always equal to the defaultmark,// there is no entry in the question_instances table for them.$wrapped->category = $question->categoryobject->id;$question->options->questions[$sequence[$wrapped->id]] = $wrapped;}$question->hints = $DB->get_records('question_hints',array('questionid' => $question->id), 'id ASC');return true;}public function save_question_options($question) {global $DB;$result = new stdClass();// This function needs to be able to handle the case where the existing set of wrapped// questions does not match the new set of wrapped questions so that some need to be// created, some modified and some deleted.// Unfortunately the code currently simply overwrites existing ones in sequence. This// will make re-marking after a re-ordering of wrapped questions impossible and// will also create difficulties if questiontype specific tables reference the id.// First we get all the existing wrapped questions.$oldwrappedquestions = [];if (isset($question->oldparent)) {if ($oldwrappedids = $DB->get_field('question_multianswer', 'sequence',['question' => $question->oldparent])) {$oldwrappedidsarray = explode(',', $oldwrappedids);$unorderedquestions = $DB->get_records_list('question', 'id', $oldwrappedidsarray);// Keep the order as given in the sequence field.foreach ($oldwrappedidsarray as $questionid) {if (isset($unorderedquestions[$questionid])) {$oldwrappedquestions[] = $unorderedquestions[$questionid];}}}}$sequence = array();foreach ($question->options->questions as $wrapped) {if (!empty($wrapped)) {// If we still have some old wrapped question ids, reuse the next of them.$wrapped->id = 0;if (is_array($oldwrappedquestions) &&$oldwrappedquestion = array_shift($oldwrappedquestions)) {$wrapped->oldid = $oldwrappedquestion->id;if ($oldwrappedquestion->qtype != $wrapped->qtype) {switch ($oldwrappedquestion->qtype) {case 'multichoice':$DB->delete_records('qtype_multichoice_options',array('questionid' => $oldwrappedquestion->id));break;case 'shortanswer':$DB->delete_records('qtype_shortanswer_options',array('questionid' => $oldwrappedquestion->id));break;case 'numerical':$DB->delete_records('question_numerical',array('question' => $oldwrappedquestion->id));break;default:throw new moodle_exception('qtypenotrecognized','qtype_multianswer', '', $oldwrappedquestion->qtype);}}}}$wrapped->name = $question->name;$wrapped->parent = $question->id;$previousid = $wrapped->id;// Save_question strips this extra bit off the category again.$wrapped->category = $question->category . ',1';$wrapped = question_bank::get_qtype($wrapped->qtype)->save_question($wrapped, clone($wrapped));$sequence[] = $wrapped->id;if ($previousid != 0 && $previousid != $wrapped->id) {// For some reasons a new question has been created// so delete the old one.question_delete_question($previousid);}}// Delete redundant wrapped questions.if (is_array($oldwrappedquestions) && count($oldwrappedquestions)) {foreach ($oldwrappedquestions as $oldwrappedquestion) {question_delete_question($oldwrappedquestion->id);}}if (!empty($sequence)) {$multianswer = new stdClass();$multianswer->question = $question->id;$multianswer->sequence = implode(',', $sequence);if ($oldid = $DB->get_field('question_multianswer', 'id',array('question' => $question->id))) {$multianswer->id = $oldid;$DB->update_record('question_multianswer', $multianswer);} else {$DB->insert_record('question_multianswer', $multianswer);}}$this->save_hints($question, true);}public function save_question($authorizedquestion, $form) {$question = qtype_multianswer_extract_question($form->questiontext);if (isset($authorizedquestion->id)) {$question->id = $authorizedquestion->id;}$question->category = $form->category;$form->defaultmark = $question->defaultmark;$form->questiontext = $question->questiontext;$form->questiontextformat = 0;$form->options = clone($question->options);unset($question->options);return parent::save_question($question, $form);}protected function make_hint($hint) {return question_hint_with_parts::load_from_record($hint);}public function delete_question($questionid, $contextid) {global $DB;$DB->delete_records('question_multianswer', array('question' => $questionid));parent::delete_question($questionid, $contextid);}protected function initialise_question_instance(question_definition $question, $questiondata) {parent::initialise_question_instance($question, $questiondata);$bits = preg_split('/\{#(\d+)\}/', $question->questiontext,-1, PREG_SPLIT_DELIM_CAPTURE);$question->textfragments[0] = array_shift($bits);$i = 1;while (!empty($bits)) {$question->places[$i] = array_shift($bits);$question->textfragments[$i] = array_shift($bits);$i += 1;}foreach ($questiondata->options->questions as $key => $subqdata) {if ($subqdata->qtype == 'subquestion_replacement') {continue;}$subqdata->contextid = $questiondata->contextid;if ($subqdata->qtype == 'multichoice') {$answerregs = array();if ($subqdata->options->shuffleanswers == 1 && isset($questiondata->options->shuffleanswers)&& $questiondata->options->shuffleanswers == 0 ) {$subqdata->options->shuffleanswers = 0;}}$question->subquestions[$key] = question_bank::make_question($subqdata);$question->subquestions[$key]->defaultmark = $subqdata->defaultmark;if (isset($subqdata->options->layout)) {$question->subquestions[$key]->layout = $subqdata->options->layout;}}}public function get_random_guess_score($questiondata) {$fractionsum = 0;$fractionmax = 0;foreach ($questiondata->options->questions as $key => $subqdata) {if ($subqdata->qtype == 'subquestion_replacement') {continue;}$fractionmax += $subqdata->defaultmark;$fractionsum += question_bank::get_qtype($subqdata->qtype)->get_random_guess_score($subqdata);}if ($fractionmax > question_utils::MARK_TOLERANCE) {return $fractionsum / $fractionmax;} else {return null;}}public function move_files($questionid, $oldcontextid, $newcontextid) {parent::move_files($questionid, $oldcontextid, $newcontextid);$this->move_files_in_hints($questionid, $oldcontextid, $newcontextid);}protected function delete_files($questionid, $contextid) {parent::delete_files($questionid, $contextid);$this->delete_files_in_hints($questionid, $contextid);}}// ANSWER_ALTERNATIVE regexes.define('ANSWER_ALTERNATIVE_FRACTION_REGEX','=|%(-?[0-9]+(?:[.,][0-9]*)?)%');// For the syntax '(?<!' see http://www.perl.com/doc/manual/html/pod/perlre.html#item_C.define('ANSWER_ALTERNATIVE_ANSWER_REGEX','.+?(?<!\\\\|&|&)(?=[~#}]|$)');define('ANSWER_ALTERNATIVE_FEEDBACK_REGEX','.*?(?<!\\\\)(?=[~}]|$)');define('ANSWER_ALTERNATIVE_REGEX','(' . ANSWER_ALTERNATIVE_FRACTION_REGEX .')?' .'(' . ANSWER_ALTERNATIVE_ANSWER_REGEX . ')' .'(#(' . ANSWER_ALTERNATIVE_FEEDBACK_REGEX .'))?');// Parenthesis positions for ANSWER_ALTERNATIVE_REGEX.define('ANSWER_ALTERNATIVE_REGEX_PERCENTILE_FRACTION', 2);define('ANSWER_ALTERNATIVE_REGEX_FRACTION', 1);define('ANSWER_ALTERNATIVE_REGEX_ANSWER', 3);define('ANSWER_ALTERNATIVE_REGEX_FEEDBACK', 5);// NUMBER_FORMATED_ALTERNATIVE_ANSWER_REGEX is used// for identifying numerical answers in ANSWER_ALTERNATIVE_REGEX_ANSWER.define('NUMBER_REGEX','-?(([0-9]+[.,]?[0-9]*|[.,][0-9]+)([eE][-+]?[0-9]+)?)');define('NUMERICAL_ALTERNATIVE_REGEX','^(' . NUMBER_REGEX . ')(:' . NUMBER_REGEX . ')?$');// Parenthesis positions for NUMERICAL_FORMATED_ALTERNATIVE_ANSWER_REGEX.define('NUMERICAL_CORRECT_ANSWER', 1);define('NUMERICAL_ABS_ERROR_MARGIN', 6);// Remaining ANSWER regexes.define('ANSWER_TYPE_DEF_REGEX','(NUMERICAL|NM)|(MULTICHOICE|MC)|(MULTICHOICE_V|MCV)|(MULTICHOICE_H|MCH)|' .'(SHORTANSWER|SA|MW)|(SHORTANSWER_C|SAC|MWC)|' .'(MULTICHOICE_S|MCS)|(MULTICHOICE_VS|MCVS)|(MULTICHOICE_HS|MCHS)|'.'(MULTIRESPONSE|MR)|(MULTIRESPONSE_H|MRH)|(MULTIRESPONSE_S|MRS)|(MULTIRESPONSE_HS|MRHS)');define('ANSWER_START_REGEX','\{([0-9]*):(' . ANSWER_TYPE_DEF_REGEX . '):');define('ANSWER_REGEX',ANSWER_START_REGEX. '(' . ANSWER_ALTERNATIVE_REGEX. '(~'. ANSWER_ALTERNATIVE_REGEX. ')*)\}');// Parenthesis positions for singulars in ANSWER_REGEX.define('ANSWER_REGEX_NORM', 1);define('ANSWER_REGEX_ANSWER_TYPE_NUMERICAL', 3);define('ANSWER_REGEX_ANSWER_TYPE_MULTICHOICE', 4);define('ANSWER_REGEX_ANSWER_TYPE_MULTICHOICE_REGULAR', 5);define('ANSWER_REGEX_ANSWER_TYPE_MULTICHOICE_HORIZONTAL', 6);define('ANSWER_REGEX_ANSWER_TYPE_SHORTANSWER', 7);define('ANSWER_REGEX_ANSWER_TYPE_SHORTANSWER_C', 8);define('ANSWER_REGEX_ANSWER_TYPE_MULTICHOICE_SHUFFLED', 9);define('ANSWER_REGEX_ANSWER_TYPE_MULTICHOICE_REGULAR_SHUFFLED', 10);define('ANSWER_REGEX_ANSWER_TYPE_MULTICHOICE_HORIZONTAL_SHUFFLED', 11);define('ANSWER_REGEX_ANSWER_TYPE_MULTIRESPONSE', 12);define('ANSWER_REGEX_ANSWER_TYPE_MULTIRESPONSE_HORIZONTAL', 13);define('ANSWER_REGEX_ANSWER_TYPE_MULTIRESPONSE_SHUFFLED', 14);define('ANSWER_REGEX_ANSWER_TYPE_MULTIRESPONSE_HORIZONTAL_SHUFFLED', 15);define('ANSWER_REGEX_ALTERNATIVES', 16);/*** Initialise subquestion fields that are constant across all MULTICHOICE* types.** @param objet $wrapped The subquestion to initialise**/function qtype_multianswer_initialise_multichoice_subquestion($wrapped) {$wrapped->qtype = 'multichoice';$wrapped->single = 1;$wrapped->answernumbering = 0;$wrapped->correctfeedback['text'] = '';$wrapped->correctfeedback['format'] = FORMAT_HTML;$wrapped->correctfeedback['itemid'] = '';$wrapped->partiallycorrectfeedback['text'] = '';$wrapped->partiallycorrectfeedback['format'] = FORMAT_HTML;$wrapped->partiallycorrectfeedback['itemid'] = '';$wrapped->incorrectfeedback['text'] = '';$wrapped->incorrectfeedback['format'] = FORMAT_HTML;$wrapped->incorrectfeedback['itemid'] = '';}function qtype_multianswer_extract_question($text) {// Variable $text is an array [text][format][itemid].$question = new stdClass();$question->qtype = 'multianswer';$question->questiontext = $text;$question->generalfeedback['text'] = '';$question->generalfeedback['format'] = FORMAT_HTML;$question->generalfeedback['itemid'] = '';$question->options = new stdClass();$question->options->questions = array();$question->defaultmark = 0; // Will be increased for each answer norm.for ($positionkey = 1;preg_match('/'.ANSWER_REGEX.'/s', $question->questiontext['text'], $answerregs);++$positionkey) {$wrapped = new stdClass();$wrapped->generalfeedback['text'] = '';$wrapped->generalfeedback['format'] = FORMAT_HTML;$wrapped->generalfeedback['itemid'] = '';if (isset($answerregs[ANSWER_REGEX_NORM]) && $answerregs[ANSWER_REGEX_NORM] !== '') {$wrapped->defaultmark = $answerregs[ANSWER_REGEX_NORM];} else {$wrapped->defaultmark = '1';}if (!empty($answerregs[ANSWER_REGEX_ANSWER_TYPE_NUMERICAL])) {$wrapped->qtype = 'numerical';$wrapped->multiplier = array();$wrapped->units = array();$wrapped->instructions['text'] = '';$wrapped->instructions['format'] = FORMAT_HTML;$wrapped->instructions['itemid'] = '';} else if (!empty($answerregs[ANSWER_REGEX_ANSWER_TYPE_SHORTANSWER])) {$wrapped->qtype = 'shortanswer';$wrapped->usecase = 0;} else if (!empty($answerregs[ANSWER_REGEX_ANSWER_TYPE_SHORTANSWER_C])) {$wrapped->qtype = 'shortanswer';$wrapped->usecase = 1;} else if (!empty($answerregs[ANSWER_REGEX_ANSWER_TYPE_MULTICHOICE])) {qtype_multianswer_initialise_multichoice_subquestion($wrapped);$wrapped->shuffleanswers = 0;$wrapped->layout = qtype_multichoice_base::LAYOUT_DROPDOWN;} else if (!empty($answerregs[ANSWER_REGEX_ANSWER_TYPE_MULTICHOICE_SHUFFLED])) {qtype_multianswer_initialise_multichoice_subquestion($wrapped);$wrapped->shuffleanswers = 1;$wrapped->layout = qtype_multichoice_base::LAYOUT_DROPDOWN;} else if (!empty($answerregs[ANSWER_REGEX_ANSWER_TYPE_MULTICHOICE_REGULAR])) {qtype_multianswer_initialise_multichoice_subquestion($wrapped);$wrapped->shuffleanswers = 0;$wrapped->layout = qtype_multichoice_base::LAYOUT_VERTICAL;} else if (!empty($answerregs[ANSWER_REGEX_ANSWER_TYPE_MULTICHOICE_REGULAR_SHUFFLED])) {qtype_multianswer_initialise_multichoice_subquestion($wrapped);$wrapped->shuffleanswers = 1;$wrapped->layout = qtype_multichoice_base::LAYOUT_VERTICAL;} else if (!empty($answerregs[ANSWER_REGEX_ANSWER_TYPE_MULTICHOICE_HORIZONTAL])) {qtype_multianswer_initialise_multichoice_subquestion($wrapped);$wrapped->shuffleanswers = 0;$wrapped->layout = qtype_multichoice_base::LAYOUT_HORIZONTAL;} else if (!empty($answerregs[ANSWER_REGEX_ANSWER_TYPE_MULTICHOICE_HORIZONTAL_SHUFFLED])) {qtype_multianswer_initialise_multichoice_subquestion($wrapped);$wrapped->shuffleanswers = 1;$wrapped->layout = qtype_multichoice_base::LAYOUT_HORIZONTAL;} else if (!empty($answerregs[ANSWER_REGEX_ANSWER_TYPE_MULTIRESPONSE])) {qtype_multianswer_initialise_multichoice_subquestion($wrapped);$wrapped->single = 0;$wrapped->shuffleanswers = 0;$wrapped->layout = qtype_multichoice_base::LAYOUT_VERTICAL;} else if (!empty($answerregs[ANSWER_REGEX_ANSWER_TYPE_MULTIRESPONSE_HORIZONTAL])) {qtype_multianswer_initialise_multichoice_subquestion($wrapped);$wrapped->single = 0;$wrapped->shuffleanswers = 0;$wrapped->layout = qtype_multichoice_base::LAYOUT_HORIZONTAL;} else if (!empty($answerregs[ANSWER_REGEX_ANSWER_TYPE_MULTIRESPONSE_SHUFFLED])) {qtype_multianswer_initialise_multichoice_subquestion($wrapped);$wrapped->single = 0;$wrapped->shuffleanswers = 1;$wrapped->layout = qtype_multichoice_base::LAYOUT_VERTICAL;} else if (!empty($answerregs[ANSWER_REGEX_ANSWER_TYPE_MULTIRESPONSE_HORIZONTAL_SHUFFLED])) {qtype_multianswer_initialise_multichoice_subquestion($wrapped);$wrapped->single = 0;$wrapped->shuffleanswers = 1;$wrapped->layout = qtype_multichoice_base::LAYOUT_HORIZONTAL;} else {throw new \moodle_exception('unknownquestiontype', 'question', '', $answerregs[2]);return false;}// Each $wrapped simulates a $form that can be processed by the// respective save_question and save_question_options methods of the// wrapped questiontypes.$wrapped->answer = array();$wrapped->fraction = array();$wrapped->feedback = array();$wrapped->questiontext['text'] = $answerregs[0];$wrapped->questiontext['format'] = FORMAT_HTML;$wrapped->questiontext['itemid'] = '';$answerindex = 0;$hasspecificfraction = false;$remainingalts = $answerregs[ANSWER_REGEX_ALTERNATIVES];while (preg_match('/~?'.ANSWER_ALTERNATIVE_REGEX.'/s', $remainingalts, $altregs)) {if ('=' == $altregs[ANSWER_ALTERNATIVE_REGEX_FRACTION]) {$wrapped->fraction["{$answerindex}"] = '1';} else if ($percentile = $altregs[ANSWER_ALTERNATIVE_REGEX_PERCENTILE_FRACTION]) {// Accept either decimal place character.$wrapped->fraction["{$answerindex}"] = .01 * str_replace(',', '.', $percentile);$hasspecificfraction = true;} else {$wrapped->fraction["{$answerindex}"] = '0';}if (isset($altregs[ANSWER_ALTERNATIVE_REGEX_FEEDBACK])) {$feedback = html_entity_decode($altregs[ANSWER_ALTERNATIVE_REGEX_FEEDBACK], ENT_QUOTES, 'UTF-8');$feedback = str_replace('\}', '}', $feedback);$wrapped->feedback["{$answerindex}"]['text'] = str_replace('\#', '#', $feedback);$wrapped->feedback["{$answerindex}"]['format'] = FORMAT_HTML;$wrapped->feedback["{$answerindex}"]['itemid'] = '';} else {$wrapped->feedback["{$answerindex}"]['text'] = '';$wrapped->feedback["{$answerindex}"]['format'] = FORMAT_HTML;$wrapped->feedback["{$answerindex}"]['itemid'] = '';}if (!empty($answerregs[ANSWER_REGEX_ANSWER_TYPE_NUMERICAL])&& preg_match('~'.NUMERICAL_ALTERNATIVE_REGEX.'~s',$altregs[ANSWER_ALTERNATIVE_REGEX_ANSWER], $numregs)) {$wrapped->answer[] = $numregs[NUMERICAL_CORRECT_ANSWER];if (array_key_exists(NUMERICAL_ABS_ERROR_MARGIN, $numregs)) {$wrapped->tolerance["{$answerindex}"] =$numregs[NUMERICAL_ABS_ERROR_MARGIN];} else {$wrapped->tolerance["{$answerindex}"] = 0;}} else { // Tolerance can stay undefined for non numerical questions.// Undo quoting done by the HTML editor.$answer = html_entity_decode($altregs[ANSWER_ALTERNATIVE_REGEX_ANSWER], ENT_QUOTES, 'UTF-8');$answer = str_replace('\}', '}', $answer);$wrapped->answer["{$answerindex}"] = str_replace('\#', '#', $answer);if ($wrapped->qtype == 'multichoice') {$wrapped->answer["{$answerindex}"] = array('text' => $wrapped->answer["{$answerindex}"],'format' => FORMAT_HTML,'itemid' => '');}}$tmp = explode($altregs[0], $remainingalts, 2);$remainingalts = $tmp[1];$answerindex++;}// Fix the score for multichoice_multi questions (as positive scores should add up to 1, not have a maximum of 1).if (isset($wrapped->single) && $wrapped->single == 0) {$total = 0;foreach ($wrapped->fraction as $idx => $fraction) {if ($fraction > 0) {$total += $fraction;}}if ($total) {foreach ($wrapped->fraction as $idx => $fraction) {if ($fraction > 0) {$wrapped->fraction[$idx] = $fraction / $total;} else if (!$hasspecificfraction) {// If no specific fractions are given, set incorrect answers to each cancel out one correct answer.$wrapped->fraction[$idx] = -(1.0 / $total);}}}}$question->defaultmark += $wrapped->defaultmark;$question->options->questions[$positionkey] = clone($wrapped);$question->questiontext['text'] = implode("{#$positionkey}",explode($answerregs[0], $question->questiontext['text'], 2));}return $question;}/*** Validate a multianswer question.** @param object $question The multianswer question to validate as returned by qtype_multianswer_extract_question* @return array Array of error messages with questions field names as keys.*/function qtype_multianswer_validate_question(stdClass $question): array {$errors = array();if (!isset($question->options->questions)) {$errors['questiontext'] = get_string('questionsmissing', 'qtype_multianswer');} else {$subquestions = fullclone($question->options->questions);if (count($subquestions)) {$sub = 1;foreach ($subquestions as $subquestion) {$prefix = 'sub_'.$sub.'_';$answercount = 0;$maxgrade = false;$maxfraction = -1;foreach ($subquestion->answer as $key => $answer) {if (is_array($answer)) {$answer = $answer['text'];}$trimmedanswer = trim($answer);if ($trimmedanswer !== '') {$answercount++;if ($subquestion->qtype == 'numerical' &&!(qtype_numerical::is_valid_number($trimmedanswer) || $trimmedanswer == '*')) {$errors[$prefix.'answer['.$key.']'] =get_string('answermustbenumberorstar', 'qtype_numerical');}if ($subquestion->fraction[$key] == 1) {$maxgrade = true;}if ($subquestion->fraction[$key] > $maxfraction) {$maxfraction = $subquestion->fraction[$key];}// For 'multiresponse' we are OK if there is at least one fraction > 0.if ($subquestion->qtype == 'multichoice' && $subquestion->single == 0 &&$subquestion->fraction[$key] > 0) {$maxgrade = true;}}}if ($subquestion->qtype == 'multichoice' && $answercount < 2) {$errors[$prefix.'answer[0]'] = get_string('notenoughanswers', 'qtype_multichoice', 2);} else if ($answercount == 0) {$errors[$prefix.'answer[0]'] = get_string('notenoughanswers', 'question', 1);}if ($maxgrade == false) {$errors[$prefix.'fraction[0]'] = get_string('fractionsnomax', 'question');}$sub++;}} else {$errors['questiontext'] = get_string('questionsmissing', 'qtype_multianswer');}}return $errors;}