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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/>.
/**
* Defines the \mod_quiz\structure class.
*
* @package mod_quiz
* @copyright 2013 The Open University
* @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
*/
namespace mod_quiz;
defined('MOODLE_INTERNAL') || die();
/**
* Quiz structure class.
*
* The structure of the quiz. That is, which questions it is built up
* from. This is used on the Edit quiz page (edit.php) and also when
* starting an attempt at the quiz (startattempt.php). Once an attempt
* has been started, then the attempt holds the specific set of questions
* that that student should answer, and we no longer use this class.
*
* @copyright 2014 The Open University
* @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
*/
class structure {
/** @var \quiz the quiz this is the structure of. */
protected $quizobj = null;
/**
* @var \stdClass[] the questions in this quiz. Contains the row from the questions
* table, with the data from the quiz_slots table added, and also question_categories.contextid.
*/
protected $questions = array();
/** @var \stdClass[] quiz_slots.slot => the quiz_slots rows for this quiz, agumented by sectionid. */
protected $slotsinorder = array();
/**
* @var \stdClass[] currently a dummy. Holds data that will match the
* quiz_sections, once it exists.
*/
protected $sections = array();
/** @var bool caches the results of can_be_edited. */
protected $canbeedited = null;
/** @var bool caches the results of can_add_random_question. */
protected $canaddrandom = null;
/** @var bool tracks whether tags have been loaded */
protected $hasloadedtags = false;
/**
* @var \stdClass[] the tags for slots. Indexed by slot id.
*/
protected $slottags = array();
/**
* Create an instance of this class representing an empty quiz.
* @return structure
*/
public static function create() {
return new self();
}
/**
* Create an instance of this class representing the structure of a given quiz.
* @param \quiz $quizobj the quiz.
* @return structure
*/
public static function create_for_quiz($quizobj) {
$structure = self::create();
$structure->quizobj = $quizobj;
$structure->populate_structure($quizobj->get_quiz());
return $structure;
}
/**
* Whether there are any questions in the quiz.
* @return bool true if there is at least one question in the quiz.
*/
public function has_questions() {
return !empty($this->questions);
}
/**
* Get the number of questions in the quiz.
* @return int the number of questions in the quiz.
*/
public function get_question_count() {
return count($this->questions);
}
/**
* Get the information about the question with this id.
* @param int $questionid The question id.
* @return \stdClass the data from the questions table, augmented with
* question_category.contextid, and the quiz_slots data for the question in this quiz.
*/
public function get_question_by_id($questionid) {
return $this->questions[$questionid];
}
/**
* Get the information about the question in a given slot.
* @param int $slotnumber the index of the slot in question.
* @return \stdClass the data from the questions table, augmented with
* question_category.contextid, and the quiz_slots data for the question in this quiz.
*/
public function get_question_in_slot($slotnumber) {
return $this->questions[$this->slotsinorder[$slotnumber]->questionid];
}
/**
* Get the displayed question number (or 'i') for a given slot.
* @param int $slotnumber the index of the slot in question.
* @return string the question number ot display for this slot.
*/
public function get_displayed_number_for_slot($slotnumber) {
return $this->slotsinorder[$slotnumber]->displayednumber;
}
/**
* Get the page a given slot is on.
* @param int $slotnumber the index of the slot in question.
* @return int the page number of the page that slot is on.
*/
public function get_page_number_for_slot($slotnumber) {
return $this->slotsinorder[$slotnumber]->page;
}
/**
* Get the slot id of a given slot slot.
* @param int $slotnumber the index of the slot in question.
* @return int the page number of the page that slot is on.
*/
public function get_slot_id_for_slot($slotnumber) {
return $this->slotsinorder[$slotnumber]->id;
}
/**
* Get the question type in a given slot.
* @param int $slotnumber the index of the slot in question.
* @return string the question type (e.g. multichoice).
*/
public function get_question_type_for_slot($slotnumber) {
return $this->questions[$this->slotsinorder[$slotnumber]->questionid]->qtype;
}
/**
* Whether it would be possible, given the question types, etc. for the
* question in the given slot to require that the previous question had been
* answered before this one is displayed.
* @param int $slotnumber the index of the slot in question.
* @return bool can this question require the previous one.
*/
public function can_question_depend_on_previous_slot($slotnumber) {
return $slotnumber > 1 && $this->can_finish_during_the_attempt($slotnumber - 1);
}
/**
* Whether it is possible for another question to depend on this one finishing.
* Note that the answer is not exact, because of random questions, and sometimes
* questions cannot be depended upon because of quiz options.
* @param int $slotnumber the index of the slot in question.
* @return bool can this question finish naturally during the attempt?
*/
public function can_finish_during_the_attempt($slotnumber) {
if ($this->quizobj->get_navigation_method() == QUIZ_NAVMETHOD_SEQ) {
return false;
}
if ($this->slotsinorder[$slotnumber]->section->shufflequestions) {
return false;
}
if (in_array($this->get_question_type_for_slot($slotnumber), array('random', 'missingtype'))) {
return \question_engine::can_questions_finish_during_the_attempt(
$this->quizobj->get_quiz()->preferredbehaviour);
}
if (isset($this->slotsinorder[$slotnumber]->canfinish)) {
return $this->slotsinorder[$slotnumber]->canfinish;
}
try {
$quba = \question_engine::make_questions_usage_by_activity('mod_quiz', $this->quizobj->get_context());
$tempslot = $quba->add_question(\question_bank::load_question(
$this->slotsinorder[$slotnumber]->questionid));
$quba->set_preferred_behaviour($this->quizobj->get_quiz()->preferredbehaviour);
$quba->start_all_questions();
$this->slotsinorder[$slotnumber]->canfinish = $quba->can_question_finish_during_attempt($tempslot);
return $this->slotsinorder[$slotnumber]->canfinish;
} catch (\Exception $e) {
// If the question fails to start, this should not block editing.
return false;
}
}
/**
* Whether it would be possible, given the question types, etc. for the
* question in the given slot to require that the previous question had been
* answered before this one is displayed.
* @param int $slotnumber the index of the slot in question.
* @return bool can this question require the previous one.
*/
public function is_question_dependent_on_previous_slot($slotnumber) {
return $this->slotsinorder[$slotnumber]->requireprevious;
}
/**
* Is a particular question in this attempt a real question, or something like a description.
* @param int $slotnumber the index of the slot in question.
* @return bool whether that question is a real question.
*/
public function is_real_question($slotnumber) {
return $this->get_question_in_slot($slotnumber)->length != 0;
}
/**
* Get the course id that the quiz belongs to.
* @return int the course.id for the quiz.
*/
public function get_courseid() {
return $this->quizobj->get_courseid();
}
/**
* Get the course module id of the quiz.
* @return int the course_modules.id for the quiz.
*/
public function get_cmid() {
return $this->quizobj->get_cmid();
}
/**
* Get id of the quiz.
* @return int the quiz.id for the quiz.
*/
public function get_quizid() {
return $this->quizobj->get_quizid();
}
/**
* Get the quiz object.
* @return \stdClass the quiz settings row from the database.
*/
public function get_quiz() {
return $this->quizobj->get_quiz();
}
/**
* Quizzes can only be repaginated if they have not been attempted, the
* questions are not shuffled, and there are two or more questions.
* @return bool whether this quiz can be repaginated.
*/
public function can_be_repaginated() {
return $this->can_be_edited() && $this->get_question_count() >= 2;
}
/**
* Quizzes can only be edited if they have not been attempted.
* @return bool whether the quiz can be edited.
*/
public function can_be_edited() {
if ($this->canbeedited === null) {
$this->canbeedited = !quiz_has_attempts($this->quizobj->get_quizid());
}
return $this->canbeedited;
}
/**
* This quiz can only be edited if they have not been attempted.
* Throw an exception if this is not the case.
*/
public function check_can_be_edited() {
if (!$this->can_be_edited()) {
$reportlink = quiz_attempt_summary_link_to_reports($this->get_quiz(),
$this->quizobj->get_cm(), $this->quizobj->get_context());
throw new \moodle_exception('cannoteditafterattempts', 'quiz',
new \moodle_url('/mod/quiz/edit.php', array('cmid' => $this->get_cmid())), $reportlink);
}
}
/**
* How many questions are allowed per page in the quiz.
* This setting controls how frequently extra page-breaks should be inserted
* automatically when questions are added to the quiz.
* @return int the number of questions that should be on each page of the
* quiz by default.
*/
public function get_questions_per_page() {
return $this->quizobj->get_quiz()->questionsperpage;
}
/**
* Get quiz slots.
* @return \stdClass[] the slots in this quiz.
*/
public function get_slots() {
return array_column($this->slotsinorder, null, 'id');
}
/**
* Is this slot the first one on its page?
* @param int $slotnumber the index of the slot in question.
* @return bool whether this slot the first one on its page.
*/
public function is_first_slot_on_page($slotnumber) {
if ($slotnumber == 1) {
return true;
}
return $this->slotsinorder[$slotnumber]->page != $this->slotsinorder[$slotnumber - 1]->page;
}
/**
* Is this slot the last one on its page?
* @param int $slotnumber the index of the slot in question.
* @return bool whether this slot the last one on its page.
*/
public function is_last_slot_on_page($slotnumber) {
if (!isset($this->slotsinorder[$slotnumber + 1])) {
return true;
}
return $this->slotsinorder[$slotnumber]->page != $this->slotsinorder[$slotnumber + 1]->page;
}
/**
* Is this slot the last one in its section?
* @param int $slotnumber the index of the slot in question.
* @return bool whether this slot the last one on its section.
*/
public function is_last_slot_in_section($slotnumber) {
return $slotnumber == $this->slotsinorder[$slotnumber]->section->lastslot;
}
/**
* Is this slot the only one in its section?
* @param int $slotnumber the index of the slot in question.
* @return bool whether this slot the only one on its section.
*/
public function is_only_slot_in_section($slotnumber) {
return $this->slotsinorder[$slotnumber]->section->firstslot ==
$this->slotsinorder[$slotnumber]->section->lastslot;
}
/**
* Is this slot the last one in the quiz?
* @param int $slotnumber the index of the slot in question.
* @return bool whether this slot the last one in the quiz.
*/
public function is_last_slot_in_quiz($slotnumber) {
end($this->slotsinorder);
return $slotnumber == key($this->slotsinorder);
}
/**
* Is this the first section in the quiz?
* @param \stdClass $section the quiz_sections row.
* @return bool whether this is first section in the quiz.
*/
public function is_first_section($section) {
return $section->firstslot == 1;
}
/**
* Is this the last section in the quiz?
* @param \stdClass $section the quiz_sections row.
* @return bool whether this is first section in the quiz.
*/
public function is_last_section($section) {
return $section->id == end($this->sections)->id;
}
/**
* Does this section only contain one slot?
* @param \stdClass $section the quiz_sections row.
* @return bool whether this section contains only one slot.
*/
public function is_only_one_slot_in_section($section) {
return $section->firstslot == $section->lastslot;
}
/**
* Get the final slot in the quiz.
* @return \stdClass the quiz_slots for for the final slot in the quiz.
*/
public function get_last_slot() {
return end($this->slotsinorder);
}
/**
* Get a slot by it's id. Throws an exception if it is missing.
* @param int $slotid the slot id.
* @return \stdClass the requested quiz_slots row.
* @throws \coding_exception
*/
public function get_slot_by_id($slotid) {
foreach ($this->slotsinorder as $slot) {
if ($slot->id == $slotid) {
return $slot;
}
}
throw new \coding_exception('The \'slotid\' could not be found.');
}
/**
* Get a slot by it's slot number. Throws an exception if it is missing.
*
* @param int $slotnumber The slot number
* @return \stdClass
* @throws \coding_exception
*/
public function get_slot_by_number($slotnumber) {
if (!array_key_exists($slotnumber, $this->slotsinorder)) {
throw new \coding_exception('The \'slotnumber\' could not be found.');
}
return $this->slotsinorder[$slotnumber];
}
/**
* Check whether adding a section heading is possible
* @param int $pagenumber the number of the page.
* @return boolean
*/
public function can_add_section_heading($pagenumber) {
// There is a default section heading on this page,
// do not show adding new section heading in the Add menu.
if ($pagenumber == 1) {
return false;
}
// Get an array of firstslots.
$firstslots = array();
foreach ($this->sections as $section) {
$firstslots[] = $section->firstslot;
}
foreach ($this->slotsinorder as $slot) {
if ($slot->page == $pagenumber) {
if (in_array($slot->slot, $firstslots)) {
return false;
}
}
}
// Do not show the adding section heading on the last add menu.
if ($pagenumber == 0) {
return false;
}
return true;
}
/**
* Get all the slots in a section of the quiz.
* @param int $sectionid the section id.
* @return int[] slot numbers.
*/
public function get_slots_in_section($sectionid) {
$slots = array();
foreach ($this->slotsinorder as $slot) {
if ($slot->section->id == $sectionid) {
$slots[] = $slot->slot;
}
}
return $slots;
}
/**
* Get all the sections of the quiz.
* @return \stdClass[] the sections in this quiz.
*/
public function get_sections() {
return $this->sections;
}
/**
* Get a particular section by id.
* @return \stdClass the section.
*/
public function get_section_by_id($sectionid) {
return $this->sections[$sectionid];
}
/**
* Get the number of questions in the quiz.
* @return int the number of questions in the quiz.
*/
public function get_section_count() {
return count($this->sections);
}
/**
* Get the overall quiz grade formatted for display.
* @return string the maximum grade for this quiz.
*/
public function formatted_quiz_grade() {
return quiz_format_grade($this->get_quiz(), $this->get_quiz()->grade);
}
/**
* Get the maximum mark for a question, formatted for display.
* @param int $slotnumber the index of the slot in question.
* @return string the maximum mark for the question in this slot.
*/
public function formatted_question_grade($slotnumber) {
return quiz_format_question_grade($this->get_quiz(), $this->slotsinorder[$slotnumber]->maxmark);
}
/**
* Get the number of decimal places for displyaing overall quiz grades or marks.
* @return int the number of decimal places.
*/
public function get_decimal_places_for_grades() {
return $this->get_quiz()->decimalpoints;
}
/**
* Get the number of decimal places for displyaing question marks.
* @return int the number of decimal places.
*/
public function get_decimal_places_for_question_marks() {
return quiz_get_grade_format($this->get_quiz());
}
/**
* Get any warnings to show at the top of the edit page.
* @return string[] array of strings.
*/
public function get_edit_page_warnings() {
$warnings = array();
if (quiz_has_attempts($this->quizobj->get_quizid())) {
$reviewlink = quiz_attempt_summary_link_to_reports($this->quizobj->get_quiz(),
$this->quizobj->get_cm(), $this->quizobj->get_context());
$warnings[] = get_string('cannoteditafterattempts', 'quiz', $reviewlink);
}
return $warnings;
}
/**
* Get the date information about the current state of the quiz.
* @return string[] array of two strings. First a short summary, then a longer
* explanation of the current state, e.g. for a tool-tip.
*/
public function get_dates_summary() {
$timenow = time();
$quiz = $this->quizobj->get_quiz();
// Exact open and close dates for the tool-tip.
$dates = array();
if ($quiz->timeopen > 0) {
if ($timenow > $quiz->timeopen) {
$dates[] = get_string('quizopenedon', 'quiz', userdate($quiz->timeopen));
} else {
$dates[] = get_string('quizwillopen', 'quiz', userdate($quiz->timeopen));
}
}
if ($quiz->timeclose > 0) {
if ($timenow > $quiz->timeclose) {
$dates[] = get_string('quizclosed', 'quiz', userdate($quiz->timeclose));
} else {
$dates[] = get_string('quizcloseson', 'quiz', userdate($quiz->timeclose));
}
}
if (empty($dates)) {
$dates[] = get_string('alwaysavailable', 'quiz');
}
$explanation = implode(', ', $dates);
// Brief summary on the page.
if ($timenow < $quiz->timeopen) {
$currentstatus = get_string('quizisclosedwillopen', 'quiz',
userdate($quiz->timeopen, get_string('strftimedatetimeshort', 'langconfig')));
} else if ($quiz->timeclose && $timenow <= $quiz->timeclose) {
$currentstatus = get_string('quizisopenwillclose', 'quiz',
userdate($quiz->timeclose, get_string('strftimedatetimeshort', 'langconfig')));
} else if ($quiz->timeclose && $timenow > $quiz->timeclose) {
$currentstatus = get_string('quizisclosed', 'quiz');
} else {
$currentstatus = get_string('quizisopen', 'quiz');
}
return array($currentstatus, $explanation);
}
/**
* Set up this class with the structure for a given quiz.
* @param \stdClass $quiz the quiz settings.
*/
public function populate_structure($quiz) {
global $DB;
$slots = $DB->get_records_sql("
SELECT slot.id AS slotid, slot.slot, slot.questionid, slot.page, slot.maxmark,
slot.requireprevious, q.*, qc.contextid
FROM {quiz_slots} slot
LEFT JOIN {question} q ON q.id = slot.questionid
LEFT JOIN {question_categories} qc ON qc.id = q.category
WHERE slot.quizid = ?
ORDER BY slot.slot", array($quiz->id));
$slots = $this->populate_missing_questions($slots);
$this->questions = array();
$this->slotsinorder = array();
foreach ($slots as $slotdata) {
$this->questions[$slotdata->questionid] = $slotdata;
$slot = new \stdClass();
$slot->id = $slotdata->slotid;
$slot->slot = $slotdata->slot;
$slot->quizid = $quiz->id;
$slot->page = $slotdata->page;
$slot->questionid = $slotdata->questionid;
$slot->maxmark = $slotdata->maxmark;
$slot->requireprevious = $slotdata->requireprevious;
$this->slotsinorder[$slot->slot] = $slot;
}
// Get quiz sections in ascending order of the firstslot.
$this->sections = $DB->get_records('quiz_sections', array('quizid' => $quiz->id), 'firstslot ASC');
$this->populate_slots_with_sections();
$this->populate_question_numbers();
}
/**
* Used by populate. Make up fake data for any missing questions.
* @param \stdClass[] $slots the data about the slots and questions in the quiz.
* @return \stdClass[] updated $slots array.
*/
protected function populate_missing_questions($slots) {
// Address missing question types.
foreach ($slots as $slot) {
if ($slot->qtype === null) {
// If the questiontype is missing change the question type.
$slot->id = $slot->questionid;
$slot->category = 0;
$slot->qtype = 'missingtype';
$slot->name = get_string('missingquestion', 'quiz');
$slot->slot = $slot->slot;
$slot->maxmark = 0;
$slot->requireprevious = 0;
$slot->questiontext = ' ';
$slot->questiontextformat = FORMAT_HTML;
$slot->length = 1;
} else if (!\question_bank::qtype_exists($slot->qtype)) {
$slot->qtype = 'missingtype';
}
}
return $slots;
}
/**
* Fill in the section ids for each slot.
*/
public function populate_slots_with_sections() {
$sections = array_values($this->sections);
foreach ($sections as $i => $section) {
if (isset($sections[$i + 1])) {
$section->lastslot = $sections[$i + 1]->firstslot - 1;
} else {
$section->lastslot = count($this->slotsinorder);
}
for ($slot = $section->firstslot; $slot <= $section->lastslot; $slot += 1) {
$this->slotsinorder[$slot]->section = $section;
}
}
}
/**
* Number the questions.
*/
protected function populate_question_numbers() {
$number = 1;
foreach ($this->slotsinorder as $slot) {
if ($this->questions[$slot->questionid]->length == 0) {
$slot->displayednumber = get_string('infoshort', 'quiz');
} else {
$slot->displayednumber = $number;
$number += 1;
}
}
}
/**
* Move a slot from its current location to a new location.
*
* After callig this method, this class will be in an invalid state, and
* should be discarded if you want to manipulate the structure further.
*
* @param int $idmove id of slot to be moved
* @param int $idmoveafter id of slot to come before slot being moved
* @param int $page new page number of slot being moved
* @param bool $insection if the question is moving to a place where a new
* section starts, include it in that section.
* @return void
*/
public function move_slot($idmove, $idmoveafter, $page) {
global $DB;
$this->check_can_be_edited();
$movingslot = $this->get_slot_by_id($idmove);
if (empty($movingslot)) {
throw new \moodle_exception('Bad slot ID ' . $idmove);
}
$movingslotnumber = (int) $movingslot->slot;
// Empty target slot means move slot to first.
if (empty($idmoveafter)) {
$moveafterslotnumber = 0;
} else {
$moveafterslotnumber = (int) $this->get_slot_by_id($idmoveafter)->slot;
}
// If the action came in as moving a slot to itself, normalise this to
// moving the slot to after the previous slot.
if ($moveafterslotnumber == $movingslotnumber) {
$moveafterslotnumber = $moveafterslotnumber - 1;
}
$followingslotnumber = $moveafterslotnumber + 1;
// Prevent checking against non-existance slot when already at the last slot.
if ($followingslotnumber == $movingslotnumber && !$this->is_last_slot_in_quiz($followingslotnumber)) {
$followingslotnumber += 1;
}
// Check the target page number is OK.
if ($page == 0) {
$page = 1;
}
if (($moveafterslotnumber > 0 && $page < $this->get_page_number_for_slot($moveafterslotnumber)) ||
$page < 1) {
throw new \coding_exception('The target page number is too small.');
} else if (!$this->is_last_slot_in_quiz($moveafterslotnumber) &&
$page > $this->get_page_number_for_slot($followingslotnumber)) {
throw new \coding_exception('The target page number is too large.');
}
// Work out how things are being moved.
$slotreorder = array();
if ($moveafterslotnumber > $movingslotnumber) {
// Moving down.
$slotreorder[$movingslotnumber] = $moveafterslotnumber;
for ($i = $movingslotnumber; $i < $moveafterslotnumber; $i++) {
$slotreorder[$i + 1] = $i;
}
$headingmoveafter = $movingslotnumber;
if ($this->is_last_slot_in_quiz($moveafterslotnumber) ||
$page == $this->get_page_number_for_slot($moveafterslotnumber + 1)) {
// We are moving to the start of a section, so that heading needs
// to be included in the ones that move up.
$headingmovebefore = $moveafterslotnumber + 1;
} else {
$headingmovebefore = $moveafterslotnumber;
}
$headingmovedirection = -1;
} else if ($moveafterslotnumber < $movingslotnumber - 1) {
// Moving up.
$slotreorder[$movingslotnumber] = $moveafterslotnumber + 1;
for ($i = $moveafterslotnumber + 1; $i < $movingslotnumber; $i++) {
$slotreorder[$i] = $i + 1;
}
if ($page == $this->get_page_number_for_slot($moveafterslotnumber + 1)) {
// Moving to the start of a section, don't move that section.
$headingmoveafter = $moveafterslotnumber + 1;
} else {
// Moving tot the end of the previous section, so move the heading down too.
$headingmoveafter = $moveafterslotnumber;
}
$headingmovebefore = $movingslotnumber + 1;
$headingmovedirection = 1;
} else {
// Staying in the same place, but possibly changing page/section.
if ($page > $movingslot->page) {
$headingmoveafter = $movingslotnumber;
$headingmovebefore = $movingslotnumber + 2;
$headingmovedirection = -1;
} else if ($page < $movingslot->page) {
$headingmoveafter = $movingslotnumber - 1;
$headingmovebefore = $movingslotnumber + 1;
$headingmovedirection = 1;
} else {
return; // Nothing to do.
}
}
if ($this->is_only_slot_in_section($movingslotnumber)) {
throw new \coding_exception('You cannot remove the last slot in a section.');
}
$trans = $DB->start_delegated_transaction();
// Slot has moved record new order.
if ($slotreorder) {
update_field_with_unique_index('quiz_slots', 'slot', $slotreorder,
array('quizid' => $this->get_quizid()));
}
// Page has changed. Record it.
if ($movingslot->page != $page) {
$DB->set_field('quiz_slots', 'page', $page,
array('id' => $movingslot->id));
}
// Update section fist slots.
quiz_update_section_firstslots($this->get_quizid(), $headingmovedirection,
$headingmoveafter, $headingmovebefore);
// If any pages are now empty, remove them.
$emptypages = $DB->get_fieldset_sql("
SELECT DISTINCT page - 1
FROM {quiz_slots} slot
WHERE quizid = ?
AND page > 1
AND NOT EXISTS (SELECT 1 FROM {quiz_slots} WHERE quizid = ? AND page = slot.page - 1)
ORDER BY page - 1 DESC
", array($this->get_quizid(), $this->get_quizid()));
foreach ($emptypages as $page) {
$DB->execute("
UPDATE {quiz_slots}
SET page = page - 1
WHERE quizid = ?
AND page > ?
", array($this->get_quizid(), $page));
}
$trans->allow_commit();
}
/**
* Refresh page numbering of quiz slots.
* @param \stdClass[] $slots (optional) array of slot objects.
* @return \stdClass[] array of slot objects.
*/
public function refresh_page_numbers($slots = array()) {
global $DB;
// Get slots ordered by page then slot.
if (!count($slots)) {
$slots = $DB->get_records('quiz_slots', array('quizid' => $this->get_quizid()), 'slot, page');
}
// Loop slots. Start Page number at 1 and increment as required.
$pagenumbers = array('new' => 0, 'old' => 0);
foreach ($slots as $slot) {
if ($slot->page !== $pagenumbers['old']) {
$pagenumbers['old'] = $slot->page;
++$pagenumbers['new'];
}
if ($pagenumbers['new'] == $slot->page) {
continue;
}
$slot->page = $pagenumbers['new'];
}
return $slots;
}
/**
* Refresh page numbering of quiz slots and save to the database.
* @param \stdClass $quiz the quiz object.
* @return \stdClass[] array of slot objects.
*/
public function refresh_page_numbers_and_update_db() {
global $DB;
$this->check_can_be_edited();
$slots = $this->refresh_page_numbers();
// Record new page order.
foreach ($slots as $slot) {
$DB->set_field('quiz_slots', 'page', $slot->page,
array('id' => $slot->id));
}
return $slots;
}
/**
* Remove a slot from a quiz
*
* @param int $slotnumber The number of the slot to be deleted.
* @throws \coding_exception
*/
public function remove_slot($slotnumber) {
global $DB;
$this->check_can_be_edited();
if ($this->is_only_slot_in_section($slotnumber) && $this->get_section_count() > 1) {
throw new \coding_exception('You cannot remove the last slot in a section.');
}
$slot = $DB->get_record('quiz_slots', array('quizid' => $this->get_quizid(), 'slot' => $slotnumber));
if (!$slot) {
return;
}
$maxslot = $DB->get_field_sql('SELECT MAX(slot) FROM {quiz_slots} WHERE quizid = ?', array($this->get_quizid()));
$trans = $DB->start_delegated_transaction();
$DB->delete_records('quiz_slot_tags', array('slotid' => $slot->id));
$DB->delete_records('quiz_slots', array('id' => $slot->id));
for ($i = $slot->slot + 1; $i <= $maxslot; $i++) {
$DB->set_field('quiz_slots', 'slot', $i - 1,
array('quizid' => $this->get_quizid(), 'slot' => $i));
$this->slotsinorder[$i]->slot = $i - 1;
$this->slotsinorder[$i - 1] = $this->slotsinorder[$i];
unset($this->slotsinorder[$i]);
}
$qtype = $DB->get_field('question', 'qtype', array('id' => $slot->questionid));
if ($qtype === 'random') {
// This function automatically checks if the question is in use, and won't delete if it is.
question_delete_question($slot->questionid);
}
quiz_update_section_firstslots($this->get_quizid(), -1, $slotnumber);
foreach ($this->sections as $key => $section) {
if ($section->firstslot > $slotnumber) {
$this->sections[$key]->firstslot--;
}
}
$this->populate_slots_with_sections();
$this->populate_question_numbers();
unset($this->questions[$slot->questionid]);
$this->refresh_page_numbers_and_update_db();
$trans->allow_commit();
}
/**
* Change the max mark for a slot.
*
* Saves changes to the question grades in the quiz_slots table and any
* corresponding question_attempts.
* It does not update 'sumgrades' in the quiz table.
*
* @param \stdClass $slot row from the quiz_slots table.
* @param float $maxmark the new maxmark.
* @return bool true if the new grade is different from the old one.
*/
public function update_slot_maxmark($slot, $maxmark) {
global $DB;
if (abs($maxmark - $slot->maxmark) < 1e-7) {
// Grade has not changed. Nothing to do.
return false;
}
$trans = $DB->start_delegated_transaction();
$slot->maxmark = $maxmark;
$DB->update_record('quiz_slots', $slot);
\question_engine::set_max_mark_in_attempts(new \qubaids_for_quiz($slot->quizid),
$slot->slot, $maxmark);
$trans->allow_commit();
return true;
}
/**
* Set whether the question in a particular slot requires the previous one.
* @param int $slotid id of slot.
* @param bool $requireprevious if true, set this question to require the previous one.
*/
public function update_question_dependency($slotid, $requireprevious) {
global $DB;
$DB->set_field('quiz_slots', 'requireprevious', $requireprevious, array('id' => $slotid));
}
/**
* Add/Remove a pagebreak.
*
* Saves changes to the slot page relationship in the quiz_slots table and reorders the paging
* for subsequent slots.
*
* @param int $slotid id of slot.
* @param int $type repaginate::LINK or repaginate::UNLINK.
* @return \stdClass[] array of slot objects.
*/
public function update_page_break($slotid, $type) {
global $DB;
$this->check_can_be_edited();
$quizslots = $DB->get_records('quiz_slots', array('quizid' => $this->get_quizid()), 'slot');
$repaginate = new \mod_quiz\repaginate($this->get_quizid(), $quizslots);
$repaginate->repaginate_slots($quizslots[$slotid]->slot, $type);
$slots = $this->refresh_page_numbers_and_update_db();
return $slots;
}
/**
* Add a section heading on a given page and return the sectionid
* @param int $pagenumber the number of the page where the section heading begins.
* @param string|null $heading the heading to add. If not given, a default is used.
*/
public function add_section_heading($pagenumber, $heading = null) {
global $DB;
$section = new \stdClass();
if ($heading !== null) {
$section->heading = $heading;
} else {
$section->heading = get_string('newsectionheading', 'quiz');
}
$section->quizid = $this->get_quizid();
$slotsonpage = $DB->get_records('quiz_slots', array('quizid' => $this->get_quizid(), 'page' => $pagenumber), 'slot DESC');
$section->firstslot = end($slotsonpage)->slot;
$section->shufflequestions = 0;
return $DB->insert_record('quiz_sections', $section);
}
/**
* Change the heading for a section.
* @param int $id the id of the section to change.
* @param string $newheading the new heading for this section.
*/
public function set_section_heading($id, $newheading) {
global $DB;
$section = $DB->get_record('quiz_sections', array('id' => $id), '*', MUST_EXIST);
$section->heading = $newheading;
$DB->update_record('quiz_sections', $section);
}
/**
* Change the shuffle setting for a section.
* @param int $id the id of the section to change.
* @param bool $shuffle whether this section should be shuffled.
*/
public function set_section_shuffle($id, $shuffle) {
global $DB;
$section = $DB->get_record('quiz_sections', array('id' => $id), '*', MUST_EXIST);
$section->shufflequestions = $shuffle;
$DB->update_record('quiz_sections', $section);
}
/**
* Remove the section heading with the given id
* @param int $sectionid the section to remove.
*/
public function remove_section_heading($sectionid) {
global $DB;
$section = $DB->get_record('quiz_sections', array('id' => $sectionid), '*', MUST_EXIST);
if ($section->firstslot == 1) {
throw new \coding_exception('Cannot remove the first section in a quiz.');
}
$DB->delete_records('quiz_sections', array('id' => $sectionid));
}
/**
* Set up this class with the slot tags for each of the slots.
*/
protected function populate_slot_tags() {
$slotids = array_column($this->slotsinorder, 'id');
$this->slottags = quiz_retrieve_tags_for_slot_ids($slotids);
}
/**
* Retrieve the list of slot tags for the given slot id.
*
* @param int $slotid The id for the slot
* @return \stdClass[] The list of slot tag records
*/
public function get_slot_tags_for_slot_id($slotid) {
if (!$this->hasloadedtags) {
// Lazy load the tags just in case they are never required.
$this->populate_slot_tags();
$this->hasloadedtags = true;
}
return isset($this->slottags[$slotid]) ? $this->slottags[$slotid] : [];
}
/**
* Whether the current user can add random questions to the quiz or not.
* It is only possible to add a random question if the user has the moodle/question:useall capability
* on at least one of the contexts related to the one where we are currently editing questions.
*
* @return bool
*/
public function can_add_random_questions() {
if ($this->canaddrandom === null) {
$quizcontext = $this->quizobj->get_context();
$relatedcontexts = new \question_edit_contexts($quizcontext);
$usablecontexts = $relatedcontexts->having_cap('moodle/question:useall');
$this->canaddrandom = !empty($usablecontexts);
}
return $this->canaddrandom;
}
}