2 // This file is part of Moodle - http://moodle.org/
4 // Moodle is free software: you can redistribute it and/or modify
5 // it under the terms of the GNU General Public License as published by
6 // the Free Software Foundation, either version 3 of the License, or
7 // (at your option) any later version.
9 // Moodle is distributed in the hope that it will be useful,
10 // but WITHOUT ANY WARRANTY; without even the implied warranty of
11 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 // GNU General Public License for more details.
14 // You should have received a copy of the GNU General Public License
15 // along with Moodle. If not, see <http://www.gnu.org/licenses/>.
18 * This file defines the quiz overview report class.
20 * @package quiz_overview
21 * @copyright 1999 onwards Martin Dougiamas and others {@link http://moodle.com}
22 * @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
25 use mod_quiz\local\reports\attempts_report
;
26 use mod_quiz\question\bank\qbank_helper
;
27 use mod_quiz\quiz_attempt
;
28 use mod_quiz\quiz_settings
;
30 defined('MOODLE_INTERNAL') ||
die();
32 require_once($CFG->dirroot
. '/mod/quiz/report/overview/overview_options.php');
33 require_once($CFG->dirroot
. '/mod/quiz/report/overview/overview_form.php');
34 require_once($CFG->dirroot
. '/mod/quiz/report/overview/overview_table.php');
38 * Quiz report subclass for the overview (grades) report.
40 * @copyright 1999 onwards Martin Dougiamas and others {@link http://moodle.com}
41 * @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
43 class quiz_overview_report
extends attempts_report
{
45 public function display($quiz, $cm, $course) {
48 list($currentgroup, $studentsjoins, $groupstudentsjoins, $allowedjoins) = $this->init(
49 'overview', 'quiz_overview_settings_form', $quiz, $cm, $course);
51 $options = new quiz_overview_options('overview', $quiz, $cm, $course);
53 if ($fromform = $this->form
->get_data()) {
54 $options->process_settings_from_form($fromform);
57 $options->process_settings_from_params();
60 $this->form
->set_data($options->get_initial_form_data());
62 // Load the required questions.
63 $questions = quiz_report_get_significant_questions($quiz);
64 // Prepare for downloading, if applicable.
65 $courseshortname = format_string($course->shortname
, true,
66 ['context' => context_course
::instance($course->id
)]);
67 $table = new quiz_overview_table($quiz, $this->context
, $this->qmsubselect
,
68 $options, $groupstudentsjoins, $studentsjoins, $questions, $options->get_url());
69 $filename = quiz_report_download_filename(get_string('overviewfilename', 'quiz_overview'),
70 $courseshortname, $quiz->name
);
71 $table->is_downloading($options->download
, $filename,
72 $courseshortname . ' ' . format_string($quiz->name
, true));
73 if ($table->is_downloading()) {
74 raise_memory_limit(MEMORY_EXTRA
);
77 $this->hasgroupstudents
= false;
78 if (!empty($groupstudentsjoins->joins
)) {
79 $sql = "SELECT DISTINCT u.id
81 $groupstudentsjoins->joins
82 WHERE $groupstudentsjoins->wheres";
83 $this->hasgroupstudents
= $DB->record_exists_sql($sql, $groupstudentsjoins->params
);
86 if (!empty($studentsjoins->joins
)) {
87 $sql = "SELECT DISTINCT u.id
90 WHERE $studentsjoins->wheres";
91 $hasstudents = $DB->record_exists_sql($sql, $studentsjoins->params
);
93 if ($options->attempts
== self
::ALL_WITH
) {
94 // This option is only available to users who can access all groups in
95 // groups mode, so setting allowed to empty (which means all quiz attempts
96 // are accessible, is not a security porblem.
97 $allowedjoins = new \core\dml\
sql_join();
100 $this->process_actions($quiz, $cm, $currentgroup, $groupstudentsjoins, $allowedjoins, $options->get_url());
102 $hasquestions = quiz_has_questions($quiz->id
);
105 if (!$table->is_downloading()) {
106 // Only print headers if not asked to download data.
107 $this->print_standard_header_and_messages($cm, $course, $quiz,
108 $options, $currentgroup, $hasquestions, $hasstudents);
110 // Print the display options.
111 $this->form
->display();
114 $hasstudents = $hasstudents && (!$currentgroup ||
$this->hasgroupstudents
);
115 if ($hasquestions && ($hasstudents ||
$options->attempts
== self
::ALL_WITH
)) {
116 // Construct the SQL.
117 $table->setup_sql_queries($allowedjoins);
119 if (!$table->is_downloading()) {
120 // Output the regrade buttons.
121 if (has_capability('mod/quiz:regrade', $this->context
)) {
122 $regradesneeded = $this->count_question_attempts_needing_regrade(
123 $quiz, $groupstudentsjoins);
126 $a->groupname
= format_string(groups_get_group_name($currentgroup), true, [
127 'context' => $this->context
,
129 $a->coursestudents
= get_string('participants');
130 $a->countregradeneeded
= $regradesneeded;
131 $regradealldrydolabel =
132 get_string('regradealldrydogroup', 'quiz_overview', $a);
133 $regradealldrylabel =
134 get_string('regradealldrygroup', 'quiz_overview', $a);
136 get_string('regradeallgroup', 'quiz_overview', $a);
138 $regradealldrydolabel =
139 get_string('regradealldrydo', 'quiz_overview', $regradesneeded);
140 $regradealldrylabel =
141 get_string('regradealldry', 'quiz_overview');
143 get_string('regradeall', 'quiz_overview');
145 $displayurl = new moodle_url($options->get_url(), ['sesskey' => sesskey()]);
146 echo '<div class="regradebuttons">';
147 echo '<form action="'.$displayurl->out_omit_querystring().'">';
149 echo html_writer
::input_hidden_params($displayurl);
150 echo '<input type="submit" class="btn btn-secondary" name="regradeall" value="'.$regradealllabel.'"/>';
151 echo '<input type="submit" class="btn btn-secondary ml-1" name="regradealldry" value="' .
152 $regradealldrylabel . '"/>';
153 if ($regradesneeded) {
154 echo '<input type="submit" class="btn btn-secondary ml-1" name="regradealldrydo" value="' .
155 $regradealldrydolabel . '"/>';
161 // Print information on the grading method.
162 if ($strattempthighlight = quiz_report_highlighting_grading_method(
163 $quiz, $this->qmsubselect
, $options->onlygraded
)) {
164 echo '<div class="quizattemptcounts mt-3">' . $strattempthighlight . '</div>';
168 // Define table columns.
172 if (!$table->is_downloading() && $options->checkboxcolumn
) {
173 $columnname = 'checkbox';
174 $columns[] = $columnname;
175 $headers[] = $table->checkbox_col_header($columnname);
178 $this->add_user_columns($table, $columns, $headers);
179 $this->add_state_column($columns, $headers);
180 $this->add_time_columns($columns, $headers);
182 $this->add_grade_columns($quiz, $options->usercanseegrades
, $columns, $headers, false);
183 $this->add_grade_item_columns($options->usercanseegrades
, $columns, $headers);
185 if (!$table->is_downloading() && has_capability('mod/quiz:regrade', $this->context
) &&
186 $this->has_regraded_questions($table->sql
->from
, $table->sql
->where
, $table->sql
->params
)) {
187 $columns[] = 'regraded';
188 $headers[] = get_string('regrade', 'quiz_overview');
191 if ($options->slotmarks
) {
192 foreach ($questions as $slot => $question) {
193 $columns[] = 'qsgrade' . $slot;
194 $header = get_string('qbrief', 'quiz', $question->number
);
195 if (!$table->is_downloading()) {
200 $header .= '/' . quiz_rescale_grade($question->maxmark
, $quiz, 'question');
201 $headers[] = $header;
205 $this->set_up_table_columns($table, $columns, $headers, $this->get_base_url(), $options, false);
206 $table->set_attribute('class', 'generaltable generalbox grades');
208 $table->out($options->pagesize
, true);
211 if (!$table->is_downloading() && $options->usercanseegrades
) {
212 $output = $PAGE->get_renderer('mod_quiz');
213 list($bands, $bandwidth) = self
::get_bands_count_and_width($quiz);
214 $labels = self
::get_bands_labels($bands, $bandwidth, $quiz);
216 if ($currentgroup && $this->hasgroupstudents
) {
218 FROM {quiz_grades} qg
219 JOIN {user} u on u.id = qg.userid
220 {$groupstudentsjoins->joins}
221 WHERE qg.quiz = $quiz->id AND {$groupstudentsjoins->wheres}";
222 if ($DB->record_exists_sql($sql, $groupstudentsjoins->params
)) {
223 $data = quiz_report_grade_bands($bandwidth, $bands, $quiz->id
, $groupstudentsjoins);
224 $chart = self
::get_chart($labels, $data);
225 $groupname = format_string(groups_get_group_name($currentgroup), true, [
226 'context' => $this->context
,
228 $graphname = get_string('overviewreportgraphgroup', 'quiz_overview', $groupname);
229 // Numerical range data should display in LTR even for RTL languages.
230 echo $output->chart($chart, $graphname, ['dir' => 'ltr']);
234 if ($DB->record_exists('quiz_grades', ['quiz' => $quiz->id
])) {
235 $data = quiz_report_grade_bands($bandwidth, $bands, $quiz->id
, new \core\dml\
sql_join());
236 $chart = self
::get_chart($labels, $data);
237 $graphname = get_string('overviewreportgraph', 'quiz_overview');
238 // Numerical range data should display in LTR even for RTL languages.
239 echo $output->chart($chart, $graphname, ['dir' => 'ltr']);
246 * Extends parent function processing any submitted actions.
248 * @param stdClass $quiz
249 * @param stdClass $cm
250 * @param int $currentgroup
251 * @param \core\dml\sql_join $groupstudentsjoins (joins, wheres, params)
252 * @param \core\dml\sql_join $allowedjoins (joins, wheres, params)
253 * @param moodle_url $redirecturl
255 protected function process_actions($quiz, $cm, $currentgroup, \core\dml\sql_join
$groupstudentsjoins,
256 \core\dml\sql_join
$allowedjoins, $redirecturl) {
257 parent
::process_actions($quiz, $cm, $currentgroup, $groupstudentsjoins, $allowedjoins, $redirecturl);
259 if (empty($currentgroup) ||
$this->hasgroupstudents
) {
260 if (optional_param('regrade', 0, PARAM_BOOL
) && confirm_sesskey()) {
261 if ($attemptids = optional_param_array('attemptid', [], PARAM_INT
)) {
262 $this->start_regrade($quiz, $cm);
263 $this->regrade_attempts($quiz, false, $groupstudentsjoins, $attemptids);
264 $this->finish_regrade($redirecturl);
269 if (optional_param('regradeall', 0, PARAM_BOOL
) && confirm_sesskey()) {
270 $this->start_regrade($quiz, $cm);
271 $this->regrade_attempts($quiz, false, $groupstudentsjoins);
272 $this->finish_regrade($redirecturl);
274 } else if (optional_param('regradealldry', 0, PARAM_BOOL
) && confirm_sesskey()) {
275 $this->start_regrade($quiz, $cm);
276 $this->regrade_attempts($quiz, true, $groupstudentsjoins);
277 $this->finish_regrade($redirecturl);
279 } else if (optional_param('regradealldrydo', 0, PARAM_BOOL
) && confirm_sesskey()) {
280 $this->start_regrade($quiz, $cm);
281 $this->regrade_attempts_needing_it($quiz, $groupstudentsjoins);
282 $this->finish_regrade($redirecturl);
287 * Check necessary capabilities, and start the display of the regrade progress page.
288 * @param stdClass $quiz the quiz settings.
289 * @param stdClass $cm the cm object for the quiz.
291 protected function start_regrade($quiz, $cm) {
292 require_capability('mod/quiz:regrade', $this->context
);
293 $this->print_header_and_tabs(
295 get_course($cm->course
),
302 * Finish displaying the regrade progress page.
303 * @param moodle_url $nexturl where to send the user after the regrade.
304 * @uses exit. This method never returns.
306 protected function finish_regrade($nexturl) {
308 \core\notification
::success(get_string('regradecomplete', 'quiz_overview'));
309 echo $OUTPUT->continue_button($nexturl);
310 echo $OUTPUT->footer();
315 * Unlock the session and allow the regrading process to run in the background.
317 protected function unlock_session() {
318 \core\session\manager
::write_close();
319 ignore_user_abort(true);
323 * Regrade a particular quiz attempt. Either for real ($dryrun = false), or
324 * as a pretend regrade to see which fractions would change. The outcome is
325 * stored in the quiz_overview_regrades table.
327 * Note, $attempt is not upgraded in the database. The caller needs to do that.
328 * However, $attempt->sumgrades is updated, if this is not a dry run.
330 * @param stdClass $attempt the quiz attempt to regrade.
331 * @param bool $dryrun if true, do a pretend regrade, otherwise do it for real.
332 * @param array $slots if null, regrade all questions, otherwise, just regrade
333 * the questions with those slots.
334 * @return array messages array with keys slot number, and values reasons why that slot cannot be regraded.
336 public function regrade_attempt($attempt, $dryrun = false, $slots = null): array {
338 // Need more time for a quiz with many questions.
339 core_php_time_limit
::raise(300);
341 $transaction = $DB->start_delegated_transaction();
343 $quba = question_engine
::load_questions_usage_by_activity($attempt->uniqueid
);
344 $versioninformation = qbank_helper
::get_version_information_for_questions_in_attempt(
345 $attempt, $this->context
);
347 if (is_null($slots)) {
348 $slots = $quba->get_slots();
352 $finished = $attempt->state
== quiz_attempt
::FINISHED
;
353 foreach ($slots as $slot) {
354 $qqr = new stdClass();
355 $qqr->oldfraction
= $quba->get_question_fraction($slot);
356 $otherquestionversion = question_bank
::load_question($versioninformation[$slot]->newquestionid
);
358 $message = $quba->validate_can_regrade_with_other_version($slot, $otherquestionversion);
360 $messages[$slot] = $message;
364 $quba->regrade_question($slot, $finished, null, $otherquestionversion);
366 $qqr->newfraction
= $quba->get_question_fraction($slot);
368 if (abs($qqr->oldfraction
- $qqr->newfraction
) > 1e-7) {
369 $qqr->questionusageid
= $quba->get_id();
371 $qqr->regraded
= empty($dryrun);
372 $qqr->timemodified
= time();
373 $DB->insert_record('quiz_overview_regrades', $qqr, false);
378 question_engine
::save_questions_usage_by_activity($quba);
381 'objectid' => $attempt->id
,
382 'relateduserid' => $attempt->userid
,
383 'context' => $this->context
,
385 'quizid' => $attempt->quiz
388 $event = \mod_quiz\event\attempt_regraded
::create($params);
392 $transaction->allow_commit();
394 // Really, PHP should not need this hint, but without this, we just run out of memory.
402 * Regrade attempts for this quiz, exactly which attempts are regraded is
403 * controlled by the parameters.
405 * @param stdClass $quiz the quiz settings.
406 * @param bool $dryrun if true, do a pretend regrade, otherwise do it for real.
407 * @param \core\dml\sql_join|null $groupstudentsjoins empty for all attempts, otherwise regrade attempts
409 * @param array $attemptids blank for all attempts, otherwise only regrade
410 * attempts whose id is in this list.
412 protected function regrade_attempts($quiz, $dryrun = false,
413 core\dml\sql_join
$groupstudentsjoins = null, $attemptids = []) {
415 $this->unlock_session();
417 $userfieldsapi = \core_user\fields
::for_name();
418 $sql = "SELECT quiza.*, " . $userfieldsapi->get_sql('u', false, '', '', false)->selects
. "
419 FROM {quiz_attempts} quiza
420 JOIN {user} u ON u.id = quiza.userid";
421 $where = "quiz = :qid AND preview = 0";
422 $params = ['qid' => $quiz->id
];
424 if ($this->hasgroupstudents
&& !empty($groupstudentsjoins->joins
)) {
425 $sql .= "\n{$groupstudentsjoins->joins}";
426 $where .= " AND {$groupstudentsjoins->wheres}";
427 $params +
= $groupstudentsjoins->params
;
431 list($attemptidcondition, $attemptidparams) = $DB->get_in_or_equal($attemptids, SQL_PARAMS_NAMED
);
432 $where .= " AND quiza.id $attemptidcondition";
433 $params +
= $attemptidparams;
436 $sql .= "\nWHERE {$where}";
437 $attempts = $DB->get_records_sql($sql, $params);
442 $this->regrade_batch_of_attempts($quiz, $attempts, $dryrun, $groupstudentsjoins);
446 * Regrade those questions in those attempts that are marked as needing regrading
447 * in the quiz_overview_regrades table.
448 * @param stdClass $quiz the quiz settings.
449 * @param \core\dml\sql_join $groupstudentsjoins empty for all attempts, otherwise regrade attempts
452 protected function regrade_attempts_needing_it($quiz, \core\dml\sql_join
$groupstudentsjoins) {
454 $this->unlock_session();
456 $join = '{quiz_overview_regrades} qqr ON qqr.questionusageid = quiza.uniqueid';
457 $where = "quiza.quiz = :qid AND quiza.preview = 0 AND qqr.regraded = 0";
458 $params = ['qid' => $quiz->id
];
460 // Fetch all attempts that need regrading.
461 if ($this->hasgroupstudents
&& !empty($groupstudentsjoins->joins
)) {
462 $join .= "\nJOIN {user} u ON u.id = quiza.userid
463 {$groupstudentsjoins->joins}";
464 $where .= " AND {$groupstudentsjoins->wheres}";
465 $params +
= $groupstudentsjoins->params
;
468 $toregrade = $DB->get_recordset_sql("
469 SELECT quiza.uniqueid, qqr.slot
470 FROM {quiz_attempts} quiza
472 WHERE $where", $params);
474 $attemptquestions = [];
475 foreach ($toregrade as $row) {
476 $attemptquestions[$row->uniqueid
][] = $row->slot
;
480 if (!$attemptquestions) {
484 list($uniqueidcondition, $params) = $DB->get_in_or_equal(array_keys($attemptquestions));
485 $userfieldsapi = \core_user\fields
::for_name();
486 $attempts = $DB->get_records_sql("
487 SELECT quiza.*, " . $userfieldsapi->get_sql('u', false, '', '', false)->selects
. "
488 FROM {quiz_attempts} quiza
489 JOIN {user} u ON u.id = quiza.userid
490 WHERE quiza.uniqueid $uniqueidcondition
493 foreach ($attempts as $attempt) {
494 $attempt->regradeonlyslots
= $attemptquestions[$attempt->uniqueid
];
497 $this->regrade_batch_of_attempts($quiz, $attempts, false, $groupstudentsjoins);
501 * This is a helper used by {@link regrade_attempts()} and
502 * {@link regrade_attempts_needing_it()}.
504 * Given an array of attempts, it regrades them all, or does a dry run.
505 * Each object in the attempts array must be a row from the quiz_attempts
506 * table, with the \core_user\fields::for_name() fields from the user table joined in.
507 * In addition, if $attempt->regradeonlyslots is set, then only those slots
508 * are regraded, otherwise all slots are regraded.
510 * @param stdClass $quiz the quiz settings.
511 * @param array $attempts of data from the quiz_attempts table, with extra data as above.
512 * @param bool $dryrun if true, do a pretend regrade, otherwise do it for real.
513 * @param \core\dml\sql_join $groupstudentsjoins empty for all attempts, otherwise regrade attempts
515 protected function regrade_batch_of_attempts($quiz, array $attempts,
516 bool $dryrun, \core\dml\sql_join
$groupstudentsjoins) {
518 $this->clear_regrade_table($quiz, $groupstudentsjoins);
520 $progressbar = new progress_bar('quiz_overview_regrade', 500, true);
522 'count' => count($attempts),
525 foreach ($attempts as $attempt) {
527 $a['attemptnum'] = $attempt->attempt
;
528 $a['name'] = fullname($attempt);
529 $a['attemptid'] = $attempt->id
;
530 if (!isset($attempt->regradeonlyslots
)) {
531 $attempt->regradeonlyslots
= null;
533 $progressbar->update($a['done'], $a['count'],
534 get_string('regradingattemptxofywithdetails', 'quiz_overview', $a));
535 $messages = $this->regrade_attempt($attempt, $dryrun, $attempt->regradeonlyslots
);
538 foreach ($messages as $slot => $message) {
539 $items[] = get_string('regradingattemptissue', 'quiz_overview',
540 ['slot' => $slot, 'reason' => $message]);
542 echo $OUTPUT->notification(
543 html_writer
::tag('p', get_string('regradingattemptxofyproblem', 'quiz_overview', $a)) .
544 html_writer
::alist($items), \core\output\notification
::NOTIFY_WARNING
);
547 $progressbar->update($a['done'], $a['count'],
548 get_string('regradedsuccessfullyxofy', 'quiz_overview', $a));
551 $this->update_overall_grades($quiz);
556 * Count the number of attempts in need of a regrade.
558 * @param stdClass $quiz the quiz settings.
559 * @param \core\dml\sql_join $groupstudentsjoins (joins, wheres, params) If this is given, only data relating
560 * to these users is cleared.
561 * @return int the number of attempts.
563 protected function count_question_attempts_needing_regrade($quiz, \core\dml\sql_join
$groupstudentsjoins) {
569 if ($this->hasgroupstudents
) {
570 $userjoin = "JOIN {user} u ON u.id = quiza.userid
571 {$groupstudentsjoins->joins}";
572 $usertest = "{$groupstudentsjoins->wheres} AND u.id = quiza.userid AND ";
573 $params = $groupstudentsjoins->params
;
576 $params['cquiz'] = $quiz->id
;
577 $sql = "SELECT COUNT(DISTINCT quiza.id)
578 FROM {quiz_attempts} quiza
579 JOIN {quiz_overview_regrades} qqr ON quiza.uniqueid = qqr.questionusageid
583 quiza.quiz = :cquiz AND
584 quiza.preview = 0 AND
586 return $DB->count_records_sql($sql, $params);
590 * Are there any pending regrades in the table we are going to show?
591 * @param string $from tables used by the main query.
592 * @param string $where where clause used by the main query.
593 * @param array $params required by the SQL.
594 * @return bool whether there are pending regrades.
596 protected function has_regraded_questions($from, $where, $params) {
598 return $DB->record_exists_sql("
601 JOIN {quiz_overview_regrades} qor ON qor.questionusageid = quiza.uniqueid
602 WHERE {$where}", $params);
606 * Remove all information about pending/complete regrades from the database.
607 * @param stdClass $quiz the quiz settings.
608 * @param \core\dml\sql_join $groupstudentsjoins (joins, wheres, params). If this is given, only data relating
609 * to these users is cleared.
611 protected function clear_regrade_table($quiz, \core\dml\sql_join
$groupstudentsjoins) {
614 // Fetch all attempts that need regrading.
615 $select = "questionusageid IN (
617 FROM {quiz_attempts} quiza";
618 $where = "WHERE quiza.quiz = :qid";
619 $params = ['qid' => $quiz->id
];
620 if ($this->hasgroupstudents
&& !empty($groupstudentsjoins->joins
)) {
621 $select .= "\nJOIN {user} u ON u.id = quiza.userid
622 {$groupstudentsjoins->joins}";
623 $where .= " AND {$groupstudentsjoins->wheres}";
624 $params +
= $groupstudentsjoins->params
;
626 $select .= "\n$where)";
628 $DB->delete_records_select('quiz_overview_regrades', $select, $params);
632 * Update the final grades for all attempts. This method is used following a regrade.
634 * @param stdClass $quiz the quiz settings.
636 protected function update_overall_grades($quiz) {
637 $gradecalculator = $this->quizobj
->get_grade_calculator();
638 $gradecalculator->recompute_all_attempt_sumgrades();
639 $gradecalculator->recompute_all_final_grades();
640 quiz_update_grades($quiz);
644 * Get the bands configuration for the quiz.
646 * This returns the configuration for having between 11 and 20 bars in
647 * a chart based on the maximum grade to be given on a quiz. The width of
648 * a band is the number of grade points it encapsulates.
650 * @param stdClass $quiz The quiz object.
651 * @return array Contains the number of bands, and their width.
653 public static function get_bands_count_and_width($quiz) {
654 $bands = $quiz->grade
;
655 while ($bands > 20 ||
$bands <= 10) {
658 } else if ($bands > 20) {
663 } else if ($bands <= 10) {
667 // See MDL-34589. Using doubles as array keys causes problems in PHP 5.4, hence the explicit cast to int.
668 $bands = (int) ceil($bands);
669 return [$bands, $quiz->grade
/ $bands];
673 * Get the bands labels.
675 * @param int $bands The number of bands.
676 * @param int $bandwidth The band width.
677 * @param stdClass $quiz The quiz object.
678 * @return string[] The labels.
680 public static function get_bands_labels($bands, $bandwidth, $quiz) {
682 for ($i = 1; $i <= $bands; $i++
) {
683 $bandlabels[] = quiz_format_grade($quiz, ($i - 1) * $bandwidth) . ' - ' . quiz_format_grade($quiz, $i * $bandwidth);
691 * @param string[] $labels Chart labels.
692 * @param int[] $data The data.
693 * @return \core\chart_base
695 protected static function get_chart($labels, $data) {
696 $chart = new \core\
chart_bar();
697 $chart->set_labels($labels);
698 $chart->get_xaxis(0, true)->set_label(get_string('gradenoun'));
700 $yaxis = $chart->get_yaxis(0, true);
701 $yaxis->set_label(get_string('participants'));
702 $yaxis->set_stepsize(max(1, round(max($data) / 10)));
704 $series = new \core\
chart_series(get_string('participants'), $data);
705 $chart->add_series($series);