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Developer Documentation
- Bug fixes for general core bugs in 3.11.x will end 14 Nov 2022 (12 months plus 6 months extension).
- Bug fixes for security issues in 3.11.x will end 13 Nov 2023 (18 months plus 12 months extension).
- PHP version: minimum PHP 7.3.0 Note: minimum PHP version has increased since Moodle 3.10. PHP 7.4.x is supported too.
/lib/ -> questionlib.php (source)
<?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/>.
/**
* Code for handling and processing questions
*
* This is code that is module independent, i.e., can be used by any module that
* uses questions, like quiz, lesson, ..
* This script also loads the questiontype classes
* Code for handling the editing of questions is in {@link question/editlib.php}
*
* TODO: separate those functions which form part of the API
* from the helper functions.
*
* @package moodlecore
* @subpackage questionbank
* @copyright 1999 onwards Martin Dougiamas and others {@link http://moodle.com}
* @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
*/
defined('MOODLE_INTERNAL') || die();
require_once($CFG->dirroot . '/question/engine/lib.php');
require_once($CFG->dirroot . '/question/type/questiontypebase.php');
/// CONSTANTS ///////////////////////////////////
/**
* Constant determines the number of answer boxes supplied in the editing
* form for multiple choice and similar question types.
*/
define("QUESTION_NUMANS", 10);
/**
* Constant determines the number of answer boxes supplied in the editing
* form for multiple choice and similar question types to start with, with
* the option of adding QUESTION_NUMANS_ADD more answers.
*/
define("QUESTION_NUMANS_START", 3);
/**
* Constant determines the number of answer boxes to add in the editing
* form for multiple choice and similar question types when the user presses
* 'add form fields button'.
*/
define("QUESTION_NUMANS_ADD", 3);
/**
* Move one question type in a list of question types. If you try to move one element
* off of the end, nothing will change.
*
* @param array $sortedqtypes An array $qtype => anything.
* @param string $tomove one of the keys from $sortedqtypes
* @param integer $direction +1 or -1
* @return array an array $index => $qtype, with $index from 0 to n in order, and
* the $qtypes in the same order as $sortedqtypes, except that $tomove will
* have been moved one place.
*/
function question_reorder_qtypes($sortedqtypes, $tomove, $direction) {
$neworder = array_keys($sortedqtypes);
// Find the element to move.
$key = array_search($tomove, $neworder);
if ($key === false) {
return $neworder;
}
// Work out the other index.
$otherkey = $key + $direction;
if (!isset($neworder[$otherkey])) {
return $neworder;
}
// Do the swap.
$swap = $neworder[$otherkey];
$neworder[$otherkey] = $neworder[$key];
$neworder[$key] = $swap;
return $neworder;
}
/**
* Save a new question type order to the config_plugins table.
* @global object
* @param $neworder An arra $index => $qtype. Indices should start at 0 and be in order.
* @param $config get_config('question'), if you happen to have it around, to save one DB query.
*/
function question_save_qtype_order($neworder, $config = null) {
global $DB;
if (is_null($config)) {
$config = get_config('question');
}
foreach ($neworder as $index => $qtype) {
$sortvar = $qtype . '_sortorder';
if (!isset($config->$sortvar) || $config->$sortvar != $index + 1) {
set_config($sortvar, $index + 1, 'question');
}
}
}
/// FUNCTIONS //////////////////////////////////////////////////////
/**
* @param array $questionids of question ids.
* @return boolean whether any of these questions are being used by any part of Moodle.
*/
function questions_in_use($questionids) {
// Are they used by the core question system?
if (question_engine::questions_in_use($questionids)) {
return true;
}
// Check if any plugins are using these questions.
$callbacksbytype = get_plugins_with_function('questions_in_use');
foreach ($callbacksbytype as $callbacks) {
foreach ($callbacks as $function) {
if ($function($questionids)) {
return true;
}
}
}
// Finally check legacy callback.
$legacycallbacks = get_plugin_list_with_function('mod', 'question_list_instances');
foreach ($legacycallbacks as $plugin => $function) {
debugging($plugin . ' implements deprecated method ' . $function .
'. ' . $plugin . '_questions_in_use should be implemented instead.', DEBUG_DEVELOPER);
if (isset($callbacksbytype['mod'][substr($plugin, 4)])) {
continue; // Already done.
}
foreach ($questionids as $questionid) {
if (!empty($function($questionid))) {
return true;
}
}
}
return false;
}
/**
* Determine whether there arey any questions belonging to this context, that is whether any of its
* question categories contain any questions. This will return true even if all the questions are
* hidden.
*
* @param mixed $context either a context object, or a context id.
* @return boolean whether any of the question categories beloning to this context have
* any questions in them.
*/
function question_context_has_any_questions($context) {
global $DB;
if (is_object($context)) {
$contextid = $context->id;
} else if (is_numeric($context)) {
$contextid = $context;
} else {
print_error('invalidcontextinhasanyquestions', 'question');
}
return $DB->record_exists_sql("SELECT *
FROM {question} q
JOIN {question_categories} qc ON qc.id = q.category
WHERE qc.contextid = ? AND q.parent = 0", array($contextid));
}
/**
* Check whether a given grade is one of a list of allowed options. If not,
* depending on $matchgrades, either return the nearest match, or return false
* to signal an error.
* @param array $gradeoptionsfull list of valid options
* @param int $grade grade to be tested
* @param string $matchgrades 'error' or 'nearest'
* @return mixed either 'fixed' value or false if error.
*/
function match_grade_options($gradeoptionsfull, $grade, $matchgrades = 'error') {
if ($matchgrades == 'error') {
// (Almost) exact match, or an error.
foreach ($gradeoptionsfull as $value => $option) {
// Slightly fuzzy test, never check floats for equality.
if (abs($grade - $value) < 0.00001) {
return $value; // Be sure the return the proper value.
}
}
// Didn't find a match so that's an error.
return false;
} else if ($matchgrades == 'nearest') {
// Work out nearest value
$best = false;
$bestmismatch = 2;
foreach ($gradeoptionsfull as $value => $option) {
$newmismatch = abs($grade - $value);
if ($newmismatch < $bestmismatch) {
$best = $value;
$bestmismatch = $newmismatch;
}
}
return $best;
} else {
// Unknow option passed.
throw new coding_exception('Unknown $matchgrades ' . $matchgrades .
' passed to match_grade_options');
}
}
/**
* Remove stale questions from a category.
*
* While questions should not be left behind when they are not used any more,
* it does happen, maybe via restore, or old logic, or uncovered scenarios. When
* this happens, the users are unable to delete the question category unless
* they move those stale questions to another one category, but to them the
* category is empty as it does not contain anything. The purpose of this function
* is to detect the questions that may have gone stale and remove them.
*
* You will typically use this prior to checking if the category contains questions.
*
* The stale questions (unused and hidden to the user) handled are:
* - hidden questions
* - random questions
*
* @param int $categoryid The category ID.
*/
function question_remove_stale_questions_from_category($categoryid) {
global $DB;
$select = 'category = :categoryid AND (qtype = :qtype OR hidden = :hidden)';
$params = ['categoryid' => $categoryid, 'qtype' => 'random', 'hidden' => 1];
$questions = $DB->get_recordset_select("question", $select, $params, '', 'id');
foreach ($questions as $question) {
// The function question_delete_question does not delete questions in use.
question_delete_question($question->id);
}
$questions->close();
}
/**
* Category is about to be deleted,
* 1/ All questions are deleted for this question category.
* 2/ Any questions that can't be deleted are moved to a new category
* NOTE: this function is called from lib/db/upgrade.php
*
* @param object|core_course_category $category course category object
*/
function question_category_delete_safe($category) {
global $DB;
$criteria = array('category' => $category->id);
$context = context::instance_by_id($category->contextid, IGNORE_MISSING);
$rescue = null; // See the code around the call to question_save_from_deletion.
// Deal with any questions in the category.
if ($questions = $DB->get_records('question', $criteria, '', 'id,qtype')) {
// Try to delete each question.
foreach ($questions as $question) {
question_delete_question($question->id);
}
// Check to see if there were any questions that were kept because
// they are still in use somehow, even though quizzes in courses
// in this category will already have been deleted. This could
// happen, for example, if questions are added to a course,
// and then that course is moved to another category (MDL-14802).
$questionids = $DB->get_records_menu('question', $criteria, '', 'id, 1');
if (!empty($questionids)) {
$parentcontextid = SYSCONTEXTID;
$name = get_string('unknown', 'question');
if ($context !== false) {
$name = $context->get_context_name();
$parentcontext = $context->get_parent_context();
if ($parentcontext) {
$parentcontextid = $parentcontext->id;
}
}
question_save_from_deletion(array_keys($questionids), $parentcontextid, $name, $rescue);
}
}
// Now delete the category.
$DB->delete_records('question_categories', array('id' => $category->id));
}
/**
* Tests whether any question in a category is used by any part of Moodle.
*
* @param integer $categoryid a question category id.
* @param boolean $recursive whether to check child categories too.
* @return boolean whether any question in this category is in use.
*/
function question_category_in_use($categoryid, $recursive = false) {
global $DB;
//Look at each question in the category
if ($questions = $DB->get_records_menu('question',
array('category' => $categoryid), '', 'id, 1')) {
if (questions_in_use(array_keys($questions))) {
return true;
}
}
if (!$recursive) {
return false;
}
//Look under child categories recursively
if ($children = $DB->get_records('question_categories',
array('parent' => $categoryid), '', 'id, 1')) {
foreach ($children as $child) {
if (question_category_in_use($child->id, $recursive)) {
return true;
}
}
}
return false;
}
/**
* Deletes question and all associated data from the database
*
* It will not delete a question if it is used somewhere.
*
* @param object $question The question being deleted
*/
function question_delete_question($questionid) {
global $DB;
$question = $DB->get_record_sql('
SELECT q.*, ctx.id AS contextid
FROM {question} q
LEFT JOIN {question_categories} qc ON qc.id = q.category
LEFT JOIN {context} ctx ON ctx.id = qc.contextid
WHERE q.id = ?', array($questionid));
if (!$question) {
// In some situations, for example if this was a child of a
// Cloze question that was previously deleted, the question may already
// have gone. In this case, just do nothing.
return;
}
> $questionstocheck = [$question->id];
// Do not delete a question if it is used by an activity module
>
if (questions_in_use(array($questionid))) {
> if ($question->parent) {
return;
> $questionstocheck[] = $question->parent;
}
> }
>
< if (questions_in_use(array($questionid))) {
> if (questions_in_use($questionstocheck)) {
if (!$question->contextid) {
debugging('Deleting question ' . $question->id . ' which is no longer linked to a context. ' .
'Assuming system context to avoid errors, but this may mean that some data like files, ' .
'tags, are not cleaned up.');
$question->contextid = context_system::instance()->id;
}
// Delete previews of the question.
$dm = new question_engine_data_mapper();
$dm->delete_previews($questionid);
// delete questiontype-specific data
question_bank::get_qtype($question->qtype, false)->delete_question(
$questionid, $question->contextid);
// Delete all tag instances.
core_tag_tag::remove_all_item_tags('core_question', 'question', $question->id);
// Now recursively delete all child questions
if ($children = $DB->get_records('question',
array('parent' => $questionid), '', 'id, qtype')) {
foreach ($children as $child) {
if ($child->id != $questionid) {
question_delete_question($child->id);
}
}
}
// Finally delete the question record itself
$DB->delete_records('question', array('id' => $questionid));
question_bank::notify_question_edited($questionid);
// Log the deletion of this question.
$event = \core\event\question_deleted::create_from_question_instance($question);
$event->add_record_snapshot('question', $question);
$event->trigger();
}
/**
* All question categories and their questions are deleted for this context id.
*
* @param int $contextid The contextid to delete question categories from
* @return array only returns an empty array for backwards compatibility.
*/
function question_delete_context($contextid) {
global $DB;
$fields = 'id, parent, name, contextid';
if ($categories = $DB->get_records('question_categories', array('contextid' => $contextid), 'parent', $fields)) {
//Sort categories following their tree (parent-child) relationships
//this will make the feedback more readable
$categories = sort_categories_by_tree($categories);
foreach ($categories as $category) {
question_category_delete_safe($category);
}
}
return [];
}
/**
* All question categories and their questions are deleted for this course.
*
* @param stdClass $course an object representing the activity
* @param bool $notused this argument is not used any more. Kept for backwards compatibility.
* @return bool always true.
*/
function question_delete_course($course, $notused = false) {
$coursecontext = context_course::instance($course->id);
question_delete_context($coursecontext->id);
return true;
}
/**
* Category is about to be deleted,
* 1/ All question categories and their questions are deleted for this course category.
* 2/ All questions are moved to new category
*
* @param stdClass|core_course_category $category course category object
* @param stdClass|core_course_category $newcategory empty means everything deleted, otherwise id of
* category where content moved
* @param bool $notused this argument is no longer used. Kept for backwards compatibility.
* @return boolean
*/
function question_delete_course_category($category, $newcategory, $notused=false) {
global $DB;
$context = context_coursecat::instance($category->id);
if (empty($newcategory)) {
question_delete_context($context->id);
} else {
// Move question categories to the new context.
if (!$newcontext = context_coursecat::instance($newcategory->id)) {
return false;
}
// Only move question categories if there is any question category at all!
if ($topcategory = question_get_top_category($context->id)) {
$newtopcategory = question_get_top_category($newcontext->id, true);
question_move_category_to_context($topcategory->id, $context->id, $newcontext->id);
$DB->set_field('question_categories', 'parent', $newtopcategory->id, array('parent' => $topcategory->id));
// Now delete the top category.
$DB->delete_records('question_categories', array('id' => $topcategory->id));
}
}
return true;
}
/**
* Enter description here...
*
* @param array $questionids of question ids
* @param object $newcontextid the context to create the saved category in.
* @param string $oldplace a textual description of the think being deleted,
* e.g. from get_context_name
* @param object $newcategory
* @return mixed false on
*/
function question_save_from_deletion($questionids, $newcontextid, $oldplace,
$newcategory = null) {
global $DB;
// Make a category in the parent context to move the questions to.
if (is_null($newcategory)) {
$newcategory = new stdClass();
$newcategory->parent = question_get_top_category($newcontextid, true)->id;
$newcategory->contextid = $newcontextid;
// Max length of column name in question_categories is 255.
$newcategory->name = shorten_text(get_string('questionsrescuedfrom', 'question', $oldplace), 255);
$newcategory->info = get_string('questionsrescuedfrominfo', 'question', $oldplace);
$newcategory->sortorder = 999;
$newcategory->stamp = make_unique_id_code();
$newcategory->id = $DB->insert_record('question_categories', $newcategory);
}
// Move any remaining questions to the 'saved' category.
if (!question_move_questions_to_category($questionids, $newcategory->id)) {
return false;
}
return $newcategory;
}
/**
* All question categories and their questions are deleted for this activity.
*
* @param object $cm the course module object representing the activity
* @param bool $notused the argument is not used any more. Kept for backwards compatibility.
* @return boolean
*/
function question_delete_activity($cm, $notused = false) {
global $DB;
$modcontext = context_module::instance($cm->id);
question_delete_context($modcontext->id);
return true;
}
/**
* This function will handle moving all tag instances to a new context for a
* given list of questions.
*
* Questions can be tagged in up to two contexts:
* 1.) The context the question exists in.
* 2.) The course context (if the question context is a higher context.
* E.g. course category context or system context.
*
* This means a question that exists in a higher context (e.g. course cat or
* system context) may have multiple groups of tags in any number of child
* course contexts.
*
* Questions in the course category context can be move "down" a context level
* into one of their child course contexts or activity contexts which affects the
* availability of that question in other courses / activities.
*
* In this case it makes the questions no longer available in the other course or
* activity contexts so we need to make sure that the tag instances in those other
* contexts are removed.
*
* @param stdClass[] $questions The list of question being moved (must include
* the id and contextid)
* @param context $newcontext The Moodle context the questions are being moved to
*/
function question_move_question_tags_to_new_context(array $questions, context $newcontext) {
// If the questions are moving to a new course/activity context then we need to
// find any existing tag instances from any unavailable course contexts and
// delete them because they will no longer be applicable (we don't support
// tagging questions across courses).
$instancestodelete = [];
$instancesfornewcontext = [];
$newcontextparentids = $newcontext->get_parent_context_ids();
$questionids = array_map(function($question) {
return $question->id;
}, $questions);
$questionstagobjects = core_tag_tag::get_items_tags('core_question', 'question', $questionids);
foreach ($questions as $question) {
$tagobjects = $questionstagobjects[$question->id] ?? [];
foreach ($tagobjects as $tagobject) {
$tagid = $tagobject->taginstanceid;
$tagcontextid = $tagobject->taginstancecontextid;
$istaginnewcontext = $tagcontextid == $newcontext->id;
$istaginquestioncontext = $tagcontextid == $question->contextid;
if ($istaginnewcontext) {
// This tag instance is already in the correct context so we can
// ignore it.
continue;
}
if ($istaginquestioncontext) {
// This tag instance is in the question context so it needs to be
// updated.
$instancesfornewcontext[] = $tagid;
continue;
}
// These tag instances are in neither the new context nor the
// question context so we need to determine what to do based on
// the context they are in and the new question context.
$tagcontext = context::instance_by_id($tagcontextid);
$tagcoursecontext = $tagcontext->get_course_context(false);
// The tag is in a course context if get_course_context() returns
// itself.
$istaginstancecontextcourse = !empty($tagcoursecontext)
&& $tagcontext->id == $tagcoursecontext->id;
if ($istaginstancecontextcourse) {
// If the tag instance is in a course context we need to add some
// special handling.
$tagcontextparentids = $tagcontext->get_parent_context_ids();
$isnewcontextaparent = in_array($newcontext->id, $tagcontextparentids);
$isnewcontextachild = in_array($tagcontext->id, $newcontextparentids);
if ($isnewcontextaparent) {
// If the tag instance is a course context tag and the new
// context is still a parent context to the tag context then
// we can leave this tag where it is.
continue;
} else if ($isnewcontextachild) {
// If the new context is a child context (e.g. activity) of this
// tag instance then we should move all of this tag instance
// down into the activity context along with the question.
$instancesfornewcontext[] = $tagid;
} else {
// If the tag is in a course context that is no longer a parent
// or child of the new context then this tag instance should be
// removed.
$instancestodelete[] = $tagid;
}
} else {
// This is a catch all for any tag instances not in the question
// context or a course context. These tag instances should be
// updated to the new context id. This will clean up old invalid
// data.
$instancesfornewcontext[] = $tagid;
}
}
}
if (!empty($instancestodelete)) {
// Delete any course context tags that may no longer be valid.
core_tag_tag::delete_instances_by_id($instancestodelete);
}
if (!empty($instancesfornewcontext)) {
// Update the tag instances to the new context id.
core_tag_tag::change_instances_context($instancesfornewcontext, $newcontext);
}
}
/**
* This function should be considered private to the question bank, it is called from
* question/editlib.php question/contextmoveq.php and a few similar places to to the
* work of actually moving questions and associated data. However, callers of this
* function also have to do other work, which is why you should not call this method
* directly from outside the questionbank.
*
* @param array $questionids of question ids.
* @param integer $newcategoryid the id of the category to move to.
*/
function question_move_questions_to_category($questionids, $newcategoryid) {
global $DB;
$newcontextid = $DB->get_field('question_categories', 'contextid',
array('id' => $newcategoryid));
list($questionidcondition, $params) = $DB->get_in_or_equal($questionids);
$questions = $DB->get_records_sql("
SELECT q.id, q.qtype, qc.contextid, q.idnumber, q.category
FROM {question} q
JOIN {question_categories} qc ON q.category = qc.id
WHERE q.id $questionidcondition", $params);
foreach ($questions as $question) {
if ($newcontextid != $question->contextid) {
question_bank::get_qtype($question->qtype)->move_files(
$question->id, $question->contextid, $newcontextid);
}
// Check whether there could be a clash of idnumbers in the new category.
if (((string) $question->idnumber !== '') &&
$DB->record_exists('question', ['idnumber' => $question->idnumber, 'category' => $newcategoryid])) {
$rec = $DB->get_records_select('question', "category = ? AND idnumber LIKE ?",
[$newcategoryid, $question->idnumber . '_%'], 'idnumber DESC', 'id, idnumber', 0, 1);
$unique = 1;
if (count($rec)) {
$rec = reset($rec);
$idnumber = $rec->idnumber;
if (strpos($idnumber, '_') !== false) {
$unique = substr($idnumber, strpos($idnumber, '_') + 1) + 1;
}
}
// For the move process, add a numerical increment to the idnumber. This means that if a question is
// mistakenly moved then the idnumber will not be completely lost.
$q = new stdClass();
$q->id = $question->id;
$q->category = $newcategoryid;
$q->idnumber = $question->idnumber . '_' . $unique;
$DB->update_record('question', $q);
}
// Log this question move.
$event = \core\event\question_moved::create_from_question_instance($question, context::instance_by_id($question->contextid),
['oldcategoryid' => $question->category, 'newcategoryid' => $newcategoryid]);
$event->trigger();
}
// Move the questions themselves.
$DB->set_field_select('question', 'category', $newcategoryid,
"id $questionidcondition", $params);
// Move any subquestions belonging to them.
$DB->set_field_select('question', 'category', $newcategoryid,
"parent $questionidcondition", $params);
$newcontext = context::instance_by_id($newcontextid);
question_move_question_tags_to_new_context($questions, $newcontext);
// TODO Deal with datasets.
// Purge these questions from the cache.
foreach ($questions as $question) {
question_bank::notify_question_edited($question->id);
}
return true;
}
/**
* This function helps move a question cateogry to a new context by moving all
* the files belonging to all the questions to the new context.
* Also moves subcategories.
* @param integer $categoryid the id of the category being moved.
* @param integer $oldcontextid the old context id.
* @param integer $newcontextid the new context id.
*/
function question_move_category_to_context($categoryid, $oldcontextid, $newcontextid) {
global $DB;
$questions = [];
$questionids = $DB->get_records_menu('question',
array('category' => $categoryid), '', 'id,qtype');
foreach ($questionids as $questionid => $qtype) {
question_bank::get_qtype($qtype)->move_files(
$questionid, $oldcontextid, $newcontextid);
// Purge this question from the cache.
question_bank::notify_question_edited($questionid);
$questions[] = (object) [
'id' => $questionid,
'contextid' => $oldcontextid
];
}
$newcontext = context::instance_by_id($newcontextid);
question_move_question_tags_to_new_context($questions, $newcontext);
$subcatids = $DB->get_records_menu('question_categories',
array('parent' => $categoryid), '', 'id,1');
foreach ($subcatids as $subcatid => $notused) {
$DB->set_field('question_categories', 'contextid', $newcontextid,
array('id' => $subcatid));
question_move_category_to_context($subcatid, $oldcontextid, $newcontextid);
}
}
/**
* Generate the URL for starting a new preview of a given question with the given options.
* @param integer $questionid the question to preview.
* @param string $preferredbehaviour the behaviour to use for the preview.
* @param float $maxmark the maximum to mark the question out of.
* @param question_display_options $displayoptions the display options to use.
* @param int $variant the variant of the question to preview. If null, one will
* be picked randomly.
* @param object $context context to run the preview in (affects things like
* filter settings, theme, lang, etc.) Defaults to $PAGE->context.
* @return moodle_url the URL.
*/
function question_preview_url($questionid, $preferredbehaviour = null,
$maxmark = null, $displayoptions = null, $variant = null, $context = null) {
$params = array('id' => $questionid);
if (is_null($context)) {
global $PAGE;
$context = $PAGE->context;
}
if ($context->contextlevel == CONTEXT_MODULE) {
$params['cmid'] = $context->instanceid;
} else if ($context->contextlevel == CONTEXT_COURSE) {
$params['courseid'] = $context->instanceid;
}
if (!is_null($preferredbehaviour)) {
$params['behaviour'] = $preferredbehaviour;
}
if (!is_null($maxmark)) {
$params['maxmark'] = format_float($maxmark, -1);
}
if (!is_null($displayoptions)) {
$params['correctness'] = $displayoptions->correctness;
$params['marks'] = $displayoptions->marks;
$params['markdp'] = $displayoptions->markdp;
$params['feedback'] = (bool) $displayoptions->feedback;
$params['generalfeedback'] = (bool) $displayoptions->generalfeedback;
$params['rightanswer'] = (bool) $displayoptions->rightanswer;
$params['history'] = (bool) $displayoptions->history;
}
if ($variant) {
$params['variant'] = $variant;
}
return new moodle_url('/question/preview.php', $params);
}
/**
* @return array that can be passed as $params to the {@link popup_action} constructor.
*/
function question_preview_popup_params() {
return array(
'height' => 600,
'width' => 800,
);
}
/**
* Given a list of ids, load the basic information about a set of questions from
* the questions table. The $join and $extrafields arguments can be used together
* to pull in extra data. See, for example, the usage in mod/quiz/attemptlib.php, and
* read the code below to see how the SQL is assembled. Throws exceptions on error.
*
* @param array $questionids array of question ids to load. If null, then all
* questions matched by $join will be loaded.
* @param string $extrafields extra SQL code to be added to the query.
* @param string $join extra SQL code to be added to the query.
* @param array $extraparams values for any placeholders in $join.
* You must use named placeholders.
* @param string $orderby what to order the results by. Optional, default is unspecified order.
*
* @return array partially complete question objects. You need to call get_question_options
* on them before they can be properly used.
*/
function question_preload_questions($questionids = null, $extrafields = '', $join = '',
$extraparams = array(), $orderby = '') {
global $DB;
if ($questionids === null) {
$where = '';
$params = array();
} else {
if (empty($questionids)) {
return array();
}
list($questionidcondition, $params) = $DB->get_in_or_equal(
$questionids, SQL_PARAMS_NAMED, 'qid0000');
$where = 'WHERE q.id ' . $questionidcondition;
}
if ($join) {
$join = 'JOIN ' . $join;
}
if ($extrafields) {
$extrafields = ', ' . $extrafields;
}
if ($orderby) {
$orderby = 'ORDER BY ' . $orderby;
}
$sql = "SELECT q.*, qc.contextid{$extrafields}
FROM {question} q
JOIN {question_categories} qc ON q.category = qc.id
{$join}
{$where}
{$orderby}";
// Load the questions.
$questions = $DB->get_records_sql($sql, $extraparams + $params);
foreach ($questions as $question) {
$question->_partiallyloaded = true;
}
return $questions;
}
/**
* Load a set of questions, given a list of ids. The $join and $extrafields arguments can be used
* together to pull in extra data. See, for example, the usage in mod/quiz/attempt.php, and
* read the code below to see how the SQL is assembled. Throws exceptions on error.
*
* @param array $questionids array of question ids.
* @param string $extrafields extra SQL code to be added to the query.
* @param string $join extra SQL code to be added to the query.
* @param array $extraparams values for any placeholders in $join.
* You are strongly recommended to use named placeholder.
*
* @return array question objects.
*/
function question_load_questions($questionids, $extrafields = '', $join = '') {
$questions = question_preload_questions($questionids, $extrafields, $join);
// Load the question type specific information
if (!get_question_options($questions)) {
return 'Could not load the question options';
}
return $questions;
}
/**
* Private function to factor common code out of get_question_options().
*
* @param object $question the question to tidy.
* @param stdClass $category The question_categories record for the given $question.
* @param stdClass[]|null $tagobjects The tags for the given $question.
* @param stdClass[]|null $filtercourses The courses to filter the course tags by.
*/
function _tidy_question($question, $category, array $tagobjects = null, array $filtercourses = null) {
// Load question-type specific fields.
if (!question_bank::is_qtype_installed($question->qtype)) {
$question->questiontext = html_writer::tag('p', get_string('warningmissingtype',
'qtype_missingtype')) . $question->questiontext;
}
question_bank::get_qtype($question->qtype)->get_question_options($question);
// Convert numeric fields to float. (Prevents these being displayed as 1.0000000.)
$question->defaultmark += 0;
$question->penalty += 0;
if (isset($question->_partiallyloaded)) {
unset($question->_partiallyloaded);
}
$question->categoryobject = $category;
if (!is_null($tagobjects)) {
$categorycontext = context::instance_by_id($category->contextid);
$sortedtagobjects = question_sort_tags($tagobjects, $categorycontext, $filtercourses);
$question->coursetagobjects = $sortedtagobjects->coursetagobjects;
$question->coursetags = $sortedtagobjects->coursetags;
$question->tagobjects = $sortedtagobjects->tagobjects;
$question->tags = $sortedtagobjects->tags;
}
}
/**
* Updates the question objects with question type specific
* information by calling {@link get_question_options()}
*
* Can be called either with an array of question objects or with a single
* question object.
*
* @param mixed $questions Either an array of question objects to be updated
* or just a single question object
* @param bool $loadtags load the question tags from the tags table. Optional, default false.
* @param stdClass[] $filtercourses The courses to filter the course tags by.
* @return bool Indicates success or failure.
*/
function get_question_options(&$questions, $loadtags = false, $filtercourses = null) {
global $DB;
$questionlist = is_array($questions) ? $questions : [$questions];
$categoryids = [];
$questionids = [];
if (empty($questionlist)) {
return true;
}
foreach ($questionlist as $question) {
$questionids[] = $question->id;
if (!in_array($question->category, $categoryids)) {
$categoryids[] = $question->category;
}
}
$categories = $DB->get_records_list('question_categories', 'id', $categoryids);
if ($loadtags && core_tag_tag::is_enabled('core_question', 'question')) {
$tagobjectsbyquestion = core_tag_tag::get_items_tags('core_question', 'question', $questionids);
} else {
$tagobjectsbyquestion = null;
}
foreach ($questionlist as $question) {
if (is_null($tagobjectsbyquestion)) {
$tagobjects = null;
} else {
$tagobjects = $tagobjectsbyquestion[$question->id];
}
_tidy_question($question, $categories[$question->category], $tagobjects, $filtercourses);
}
return true;
}
/**
* Sort question tags by course or normal tags.
*
* This function also search tag instances that may have a context id that don't match either a course or
* question context and fix the data setting the correct context id.
*
* @param stdClass[] $tagobjects The tags for the given $question.
* @param stdClass $categorycontext The question categories context.
* @param stdClass[]|null $filtercourses The courses to filter the course tags by.
* @return stdClass $sortedtagobjects Sorted tag objects.
*/
function question_sort_tags($tagobjects, $categorycontext, $filtercourses = null) {
// Questions can have two sets of tag instances. One set at the
// course context level and another at the context the question
// belongs to (e.g. course category, system etc).
$sortedtagobjects = new stdClass();
$sortedtagobjects->coursetagobjects = [];
$sortedtagobjects->coursetags = [];
$sortedtagobjects->tagobjects = [];
$sortedtagobjects->tags = [];
$taginstanceidstonormalise = [];
$filtercoursecontextids = [];
$hasfiltercourses = !empty($filtercourses);
if ($hasfiltercourses) {
// If we're being asked to filter the course tags by a set of courses
// then get the context ids to filter below.
$filtercoursecontextids = array_map(function($course) {
$coursecontext = context_course::instance($course->id);
return $coursecontext->id;
}, $filtercourses);
}
foreach ($tagobjects as $tagobject) {
$tagcontextid = $tagobject->taginstancecontextid;
$tagcontext = context::instance_by_id($tagcontextid);
$tagcoursecontext = $tagcontext->get_course_context(false);
// This is a course tag if the tag context is a course context which
// doesn't match the question's context. Any tag in the question context
// is not considered a course tag, it belongs to the question.
$iscoursetag = $tagcoursecontext
&& $tagcontext->id == $tagcoursecontext->id
&& $tagcontext->id != $categorycontext->id;
if ($iscoursetag) {
// Any tag instance in a course context level is considered a course tag.
if (!$hasfiltercourses || in_array($tagcontextid, $filtercoursecontextids)) {
// Add the tag to the list of course tags if we aren't being
// asked to filter or if this tag is in the list of courses
// we're being asked to filter by.
$sortedtagobjects->coursetagobjects[] = $tagobject;
$sortedtagobjects->coursetags[$tagobject->id] = $tagobject->get_display_name();
}
} else {
// All non course context level tag instances or tags in the question
// context belong to the context that the question was created in.
$sortedtagobjects->tagobjects[] = $tagobject;
$sortedtagobjects->tags[$tagobject->id] = $tagobject->get_display_name();
// Due to legacy tag implementations that don't force the recording
// of a context id, some tag instances may have context ids that don't
// match either a course context or the question context. In this case
// we should take the opportunity to fix up the data and set the correct
// context id.
if ($tagcontext->id != $categorycontext->id) {
$taginstanceidstonormalise[] = $tagobject->taginstanceid;
// Update the object properties to reflect the DB update that will
// happen below.
$tagobject->taginstancecontextid = $categorycontext->id;
}
}
}
if (!empty($taginstanceidstonormalise)) {
// If we found any tag instances with incorrect context id data then we can
// correct those values now by setting them to the question context id.
core_tag_tag::change_instances_context($taginstanceidstonormalise, $categorycontext);
}
return $sortedtagobjects;
}
/**
* Print the icon for the question type
*
* @param object $question The question object for which the icon is required.
* Only $question->qtype is used.
* @return string the HTML for the img tag.
*/
function print_question_icon($question) {
global $PAGE;
return $PAGE->get_renderer('question', 'bank')->qtype_icon($question->qtype);
}
/**
* Creates a stamp that uniquely identifies this version of the question
*
* In future we want this to use a hash of the question data to guarantee that
* identical versions have the same version stamp.
*
* @param object $question
* @return string A unique version stamp
*/
function question_hash($question) {
return make_unique_id_code();
}
/// CATEGORY FUNCTIONS /////////////////////////////////////////////////////////////////
/**
* returns the categories with their names ordered following parent-child relationships
* finally it tries to return pending categories (those being orphaned, whose parent is
* incorrect) to avoid missing any category from original array.
*/
function sort_categories_by_tree(&$categories, $id = 0, $level = 1) {
global $DB;
$children = array();
$keys = array_keys($categories);
foreach ($keys as $key) {
if (!isset($categories[$key]->processed) && $categories[$key]->parent == $id) {
$children[$key] = $categories[$key];
$categories[$key]->processed = true;
$children = $children + sort_categories_by_tree(
$categories, $children[$key]->id, $level+1);
}
}
//If level = 1, we have finished, try to look for non processed categories
// (bad parent) and sort them too
if ($level == 1) {
foreach ($keys as $key) {
// If not processed and it's a good candidate to start (because its
// parent doesn't exist in the course)
if (!isset($categories[$key]->processed) && !$DB->record_exists('question_categories',
array('contextid' => $categories[$key]->contextid,
'id' => $categories[$key]->parent))) {
$children[$key] = $categories[$key];
$categories[$key]->processed = true;
$children = $children + sort_categories_by_tree(
$categories, $children[$key]->id, $level + 1);
}
}
}
return $children;
}
/**
* Private method, only for the use of add_indented_names().
*
* Recursively adds an indentedname field to each category, starting with the category
* with id $id, and dealing with that category and all its children, and
* return a new array, with those categories in the right order.
*
* @param array $categories an array of categories which has had childids
* fields added by flatten_category_tree(). Passed by reference for
* performance only. It is not modfied.
* @param int $id the category to start the indenting process from.
* @param int $depth the indent depth. Used in recursive calls.
* @return array a new array of categories, in the right order for the tree.
*/
function flatten_category_tree(&$categories, $id, $depth = 0, $nochildrenof = -1) {
// Indent the name of this category.
$newcategories = array();
$newcategories[$id] = $categories[$id];
$newcategories[$id]->indentedname = str_repeat(' ', $depth) .
$categories[$id]->name;
// Recursively indent the children.
foreach ($categories[$id]->childids as $childid) {
if ($childid != $nochildrenof) {
$newcategories = $newcategories + flatten_category_tree(
$categories, $childid, $depth + 1, $nochildrenof);
}
}
// Remove the childids array that were temporarily added.
unset($newcategories[$id]->childids);
return $newcategories;
}
/**
* Format categories into an indented list reflecting the tree structure.
*
* @param array $categories An array of category objects, for example from the.
* @return array The formatted list of categories.
*/
function add_indented_names($categories, $nochildrenof = -1) {
// Add an array to each category to hold the child category ids. This array
// will be removed again by flatten_category_tree(). It should not be used
// outside these two functions.
foreach (array_keys($categories) as $id) {
$categories[$id]->childids = array();
}
// Build the tree structure, and record which categories are top-level.
// We have to be careful, because the categories array may include published
// categories from other courses, but not their parents.
$toplevelcategoryids = array();
foreach (array_keys($categories) as $id) {
if (!empty($categories[$id]->parent) &&
array_key_exists($categories[$id]->parent, $categories)) {
$categories[$categories[$id]->parent]->childids[] = $id;
} else {
$toplevelcategoryids[] = $id;
}
}
// Flatten the tree to and add the indents.
$newcategories = array();
foreach ($toplevelcategoryids as $id) {
$newcategories = $newcategories + flatten_category_tree(
$categories, $id, 0, $nochildrenof);
}
return $newcategories;
}
/**
* Output a select menu of question categories.
*
* Categories from this course and (optionally) published categories from other courses
* are included. Optionally, only categories the current user may edit can be included.
*
* @param integer $courseid the id of the course to get the categories for.
* @param integer $published if true, include publised categories from other courses.
* @param integer $only_editable if true, exclude categories this user is not allowed to edit.
* @param integer $selected optionally, the id of a category to be selected by
* default in the dropdown.
*/
function question_category_select_menu($contexts, $top = false, $currentcat = 0,
$selected = "", $nochildrenof = -1) {
$categoriesarray = question_category_options($contexts, $top, $currentcat,
false, $nochildrenof, false);
if ($selected) {
$choose = '';
} else {
$choose = 'choosedots';
}
$options = array();
foreach ($categoriesarray as $group => $opts) {
$options[] = array($group => $opts);
}
echo html_writer::label(get_string('questioncategory', 'core_question'), 'id_movetocategory', false, array('class' => 'accesshide'));
$attrs = array(
'id' => 'id_movetocategory',
'class' => 'custom-select',
'data-action' => 'toggle',
'data-togglegroup' => 'qbank',
'data-toggle' => 'action',
'disabled' => true,
);
echo html_writer::select($options, 'category', $selected, $choose, $attrs);
}
/**
* @param integer $contextid a context id.
* @return object the default question category for that context, or false if none.
*/
function question_get_default_category($contextid) {
global $DB;
$category = $DB->get_records_select('question_categories', 'contextid = ? AND parent <> 0',
array($contextid), 'id', '*', 0, 1);
if (!empty($category)) {
return reset($category);
} else {
return false;
}
}
/**
* Gets the top category in the given context.
* This function can optionally create the top category if it doesn't exist.
*
* @param int $contextid A context id.
* @param bool $create Whether create a top category if it doesn't exist.
* @return bool|stdClass The top question category for that context, or false if none.
*/
function question_get_top_category($contextid, $create = false) {
global $DB;
$category = $DB->get_record('question_categories',
array('contextid' => $contextid, 'parent' => 0));
if (!$category && $create) {
// We need to make one.
$category = new stdClass();
$category->name = 'top'; // A non-real name for the top category. It will be localised at the display time.
$category->info = '';
$category->contextid = $contextid;
$category->parent = 0;
$category->sortorder = 0;
$category->stamp = make_unique_id_code();
$category->id = $DB->insert_record('question_categories', $category);
}
return $category;
}
/**
* Gets the list of top categories in the given contexts in the array("categoryid,categorycontextid") format.
*
* @param array $contextids List of context ids
* @return array
*/
function question_get_top_categories_for_contexts($contextids) {
global $DB;
$concatsql = $DB->sql_concat_join("','", ['id', 'contextid']);
list($insql, $params) = $DB->get_in_or_equal($contextids);
$sql = "SELECT $concatsql FROM {question_categories} WHERE contextid $insql AND parent = 0";
$topcategories = $DB->get_fieldset_sql($sql, $params);
return $topcategories;
}
/**
* Gets the default category in the most specific context.
* If no categories exist yet then default ones are created in all contexts.
*
* @param array $contexts The context objects for this context and all parent contexts.
* @return object The default category - the category in the course context
*/
function question_make_default_categories($contexts) {
global $DB;
static $preferredlevels = array(
CONTEXT_COURSE => 4,
CONTEXT_MODULE => 3,
CONTEXT_COURSECAT => 2,
CONTEXT_SYSTEM => 1,
);
$toreturn = null;
$preferredness = 0;
// If it already exists, just return it.
foreach ($contexts as $key => $context) {
$topcategory = question_get_top_category($context->id, true);
if (!$exists = $DB->record_exists("question_categories",
array('contextid' => $context->id, 'parent' => $topcategory->id))) {
// Otherwise, we need to make one
$category = new stdClass();
$contextname = $context->get_context_name(false, true);
// Max length of name field is 255.
$category->name = shorten_text(get_string('defaultfor', 'question', $contextname), 255);
$category->info = get_string('defaultinfofor', 'question', $contextname);
$category->contextid = $context->id;
$category->parent = $topcategory->id;
// By default, all categories get this number, and are sorted alphabetically.
$category->sortorder = 999;
$category->stamp = make_unique_id_code();
$category->id = $DB->insert_record('question_categories', $category);
} else {
$category = question_get_default_category($context->id);
}
$thispreferredness = $preferredlevels[$context->contextlevel];
if (has_any_capability(array('moodle/question:usemine', 'moodle/question:useall'), $context)) {
$thispreferredness += 10;
}
if ($thispreferredness > $preferredness) {
$toreturn = $category;
$preferredness = $thispreferredness;
}
}
if (!is_null($toreturn)) {
$toreturn = clone($toreturn);
}
return $toreturn;
}
/**
* Get all the category objects, including a count of the number of questions in that category,
* for all the categories in the lists $contexts.
*
* @param mixed $contexts either a single contextid, or a comma-separated list of context ids.
* @param string $sortorder used as the ORDER BY clause in the select statement.
* @param bool $top Whether to return the top categories or not.
* @return array of category objects.
*/
function get_categories_for_contexts($contexts, $sortorder = 'parent, sortorder, name ASC', $top = false) {
global $DB;
$topwhere = $top ? '' : 'AND c.parent <> 0';
return $DB->get_records_sql("
SELECT c.*, (SELECT count(1) FROM {question} q
WHERE c.id = q.category AND q.hidden='0' AND q.parent='0') AS questioncount
FROM {question_categories} c
WHERE c.contextid IN ($contexts) $topwhere
ORDER BY $sortorder");
}
/**
* Output an array of question categories.
*
* @param array $contexts The list of contexts.
* @param bool $top Whether to return the top categories or not.
* @param int $currentcat
* @param bool $popupform
* @param int $nochildrenof
* @param boolean $escapecontextnames Whether the returned name of the thing is to be HTML escaped or not.
* @return array
*/
function question_category_options($contexts, $top = false, $currentcat = 0,
$popupform = false, $nochildrenof = -1, $escapecontextnames = true) {
global $CFG;
$pcontexts = array();
foreach ($contexts as $context) {
$pcontexts[] = $context->id;
}
$contextslist = join(', ', $pcontexts);
$categories = get_categories_for_contexts($contextslist, 'parent, sortorder, name ASC', $top);
if ($top) {
$categories = question_fix_top_names($categories);
}
$categories = question_add_context_in_key($categories);
$categories = add_indented_names($categories, $nochildrenof);
// sort cats out into different contexts
$categoriesarray = array();
foreach ($pcontexts as $contextid) {
$context = context::instance_by_id($contextid);
$contextstring = $context->get_context_name(true, true, $escapecontextnames);
foreach ($categories as $category) {
if ($category->contextid == $contextid) {
$cid = $category->id;
if ($currentcat != $cid || $currentcat == 0) {
$a = new stdClass;
$a->name = format_string($category->indentedname, true,
array('context' => $context));
if ($category->idnumber !== null && $category->idnumber !== '') {
$a->idnumber = s($category->idnumber);
}
if (!empty($category->questioncount)) {
$a->questioncount = $category->questioncount;
}
if (isset($a->idnumber) && isset($a->questioncount)) {
$formattedname = get_string('categorynamewithidnumberandcount', 'question', $a);
} else if (isset($a->idnumber)) {
$formattedname = get_string('categorynamewithidnumber', 'question', $a);
} else if (isset($a->questioncount)) {
$formattedname = get_string('categorynamewithcount', 'question', $a);
} else {
$formattedname = $a->name;
}
$categoriesarray[$contextstring][$cid] = $formattedname;
}
}
}
}
if ($popupform) {
$popupcats = array();
foreach ($categoriesarray as $contextstring => $optgroup) {
$group = array();
foreach ($optgroup as $key => $value) {
$key = str_replace($CFG->wwwroot, '', $key);
$group[$key] = $value;
}
$popupcats[] = array($contextstring => $group);
}
return $popupcats;
} else {
return $categoriesarray;
}
}
function question_add_context_in_key($categories) {
$newcatarray = array();
foreach ($categories as $id => $category) {
$category->parent = "$category->parent,$category->contextid";
$category->id = "$category->id,$category->contextid";
$newcatarray["$id,$category->contextid"] = $category;
}
return $newcatarray;
}
/**
* Finds top categories in the given categories hierarchy and replace their name with a proper localised string.
*
* @param array $categories An array of question categories.
* @param boolean $escape Whether the returned name of the thing is to be HTML escaped or not.
* @return array The same question category list given to the function, with the top category names being translated.
*/
function question_fix_top_names($categories, $escape = true) {
foreach ($categories as $id => $category) {
if ($category->parent == 0) {
$context = context::instance_by_id($category->contextid);
$categories[$id]->name = get_string('topfor', 'question', $context->get_context_name(false, false, $escape));
}
}
return $categories;
}
/**
* @return array of question category ids of the category and all subcategories.
*/
function question_categorylist($categoryid) {
global $DB;
// final list of category IDs
$categorylist = array();
// a list of category IDs to check for any sub-categories
$subcategories = array($categoryid);
while ($subcategories) {
foreach ($subcategories as $subcategory) {
// if anything from the temporary list was added already, then we have a loop
if (isset($categorylist[$subcategory])) {
throw new coding_exception("Category id=$subcategory is already on the list - loop of categories detected.");
}
$categorylist[$subcategory] = $subcategory;
}
list ($in, $params) = $DB->get_in_or_equal($subcategories);
$subcategories = $DB->get_records_select_menu('question_categories',
"parent $in", $params, NULL, 'id,id AS id2');
}
return $categorylist;
}
/**
* Get all parent categories of a given question category in decending order.
* @param int $categoryid for which you want to find the parents.
* @return array of question category ids of all parents categories.
*/
function question_categorylist_parents(int $categoryid) {
global $DB;
$parent = $DB->get_field('question_categories', 'parent', array('id' => $categoryid));
if (!$parent) {
return [];
}
$categorylist = [$parent];
$currentid = $parent;
while ($currentid) {
$currentid = $DB->get_field('question_categories', 'parent', array('id' => $currentid));
if ($currentid) {
$categorylist[] = $currentid;
}
}
// Present the list in decending order (the top category at the top).
$categorylist = array_reverse($categorylist);
return $categorylist;
}
//===========================
// Import/Export Functions
//===========================
/**
* Get list of available import or export formats
* @param string $type 'import' if import list, otherwise export list assumed
* @return array sorted list of import/export formats available
*/
function get_import_export_formats($type) {
global $CFG;
require_once($CFG->dirroot . '/question/format.php');
$formatclasses = core_component::get_plugin_list_with_class('qformat', '', 'format.php');
$fileformatname = array();
foreach ($formatclasses as $component => $formatclass) {
$format = new $formatclass();
if ($type == 'import') {
$provided = $format->provide_import();
} else {
$provided = $format->provide_export();
}
if ($provided) {
list($notused, $fileformat) = explode('_', $component, 2);
$fileformatnames[$fileformat] = get_string('pluginname', $component);
}
}
core_collator::asort($fileformatnames);
return $fileformatnames;
}
/**
* Create a reasonable default file name for exporting questions from a particular
* category.
* @param object $course the course the questions are in.
* @param object $category the question category.
* @return string the filename.
*/
function question_default_export_filename($course, $category) {
// We build a string that is an appropriate name (questions) from the lang pack,
// then the corse shortname, then the question category name, then a timestamp.
$base = clean_filename(get_string('exportfilename', 'question'));
$dateformat = str_replace(' ', '_', get_string('exportnameformat', 'question'));
$timestamp = clean_filename(userdate(time(), $dateformat, 99, false));
$shortname = clean_filename($course->shortname);
if ($shortname == '' || $shortname == '_' ) {
$shortname = $course->id;
}
$categoryname = clean_filename(format_string($category->name));
return "{$base}-{$shortname}-{$categoryname}-{$timestamp}";
return $export_name;
}
/**
* Converts contextlevels to strings and back to help with reading/writing contexts
* to/from import/export files.
*
* @copyright 1999 onwards Martin Dougiamas {@link http://moodle.com}
* @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
*/
class context_to_string_translator{
/**
* @var array used to translate between contextids and strings for this context.
*/
protected $contexttostringarray = array();
public function __construct($contexts) {
$this->generate_context_to_string_array($contexts);
}
public function context_to_string($contextid) {
return $this->contexttostringarray[$contextid];
}
public function string_to_context($contextname) {
$contextid = array_search($contextname, $this->contexttostringarray);
return $contextid;
}
protected function generate_context_to_string_array($contexts) {
if (!$this->contexttostringarray) {
$catno = 1;
foreach ($contexts as $context) {
switch ($context->contextlevel) {
case CONTEXT_MODULE :
$contextstring = 'module';
break;
case CONTEXT_COURSE :
$contextstring = 'course';
break;
case CONTEXT_COURSECAT :
$contextstring = "cat$catno";
$catno++;
break;
case CONTEXT_SYSTEM :
$contextstring = 'system';
break;
}
$this->contexttostringarray[$context->id] = $contextstring;
}
}
}
}
/**
* Check capability on category
*
* @param int|stdClass|question_definition $questionorid object or id.
* If an object is passed, it should include ->contextid and ->createdby.
* @param string $cap 'add', 'edit', 'view', 'use', 'move' or 'tag'.
* @param int $notused no longer used.
* @return bool this user has the capability $cap for this question $question?
* @throws coding_exception
*/
function question_has_capability_on($questionorid, $cap, $notused = -1) {
global $USER, $DB;
if (is_numeric($questionorid)) {
$questionid = (int)$questionorid;
} else if (is_object($questionorid)) {
// All we really need in this function is the contextid and author of the question.
// We won't bother fetching other details of the question if these 2 fields are provided.
if (isset($questionorid->contextid) && isset($questionorid->createdby)) {
$question = $questionorid;
} else if (!empty($questionorid->id)) {
$questionid = $questionorid->id;
}
}
// At this point, either $question or $questionid is expected to be set.
if (isset($questionid)) {
try {
$question = question_bank::load_question_data($questionid);
} catch (Exception $e) {
// Let's log the exception for future debugging,
// but not during Behat, or we can't test these cases.
if (!defined('BEHAT_SITE_RUNNING')) {
debugging($e->getMessage(), DEBUG_NORMAL, $e->getTrace());
}
// Well, at least we tried. Seems that we really have to read from DB.
$question = $DB->get_record_sql('SELECT q.id, q.createdby, qc.contextid
FROM {question} q
JOIN {question_categories} qc ON q.category = qc.id
WHERE q.id = :id', ['id' => $questionid]);
}
}
if (!isset($question)) {
throw new coding_exception('$questionorid parameter needs to be an integer or an object.');
}
$context = context::instance_by_id($question->contextid);
// These are existing questions capabilities that are set per category.
// Each of these has a 'mine' and 'all' version that is appended to the capability name.
$capabilitieswithallandmine = ['edit' => 1, 'view' => 1, 'use' => 1, 'move' => 1, 'tag' => 1];
if (!isset($capabilitieswithallandmine[$cap])) {
return has_capability('moodle/question:' . $cap, $context);
} else {
return has_capability('moodle/question:' . $cap . 'all', $context) ||
($question->createdby == $USER->id && has_capability('moodle/question:' . $cap . 'mine', $context));
}
}
/**
* Require capability on question.
*/
function question_require_capability_on($question, $cap) {
if (!question_has_capability_on($question, $cap)) {
print_error('nopermissions', '', '', $cap);
}
return true;
}
/**
* @param object $context a context
* @return string A URL for editing questions in this context.
*/
function question_edit_url($context) {
global $CFG, $SITE;
if (!has_any_capability(question_get_question_capabilities(), $context)) {
return false;
}
$baseurl = $CFG->wwwroot . '/question/edit.php?';
$defaultcategory = question_get_default_category($context->id);
if ($defaultcategory) {
$baseurl .= 'cat=' . $defaultcategory->id . ',' . $context->id . '&';
}
switch ($context->contextlevel) {
case CONTEXT_SYSTEM:
return $baseurl . 'courseid=' . $SITE->id;
case CONTEXT_COURSECAT:
// This is nasty, becuase we can only edit questions in a course
// context at the moment, so for now we just return false.
return false;
case CONTEXT_COURSE:
return $baseurl . 'courseid=' . $context->instanceid;
case CONTEXT_MODULE:
return $baseurl . 'cmid=' . $context->instanceid;
}
}
/**
* Adds question bank setting links to the given navigation node if caps are met.
*
* @param navigation_node $navigationnode The navigation node to add the question branch to
* @param object $context
* @return navigation_node Returns the question branch that was added
*/
function question_extend_settings_navigation(navigation_node $navigationnode, $context) {
global $PAGE;
if ($context->contextlevel == CONTEXT_COURSE) {
$params = array('courseid'=>$context->instanceid);
} else if ($context->contextlevel == CONTEXT_MODULE) {
$params = array('cmid'=>$context->instanceid);
} else {
return;
}
if (($cat = $PAGE->url->param('cat')) && preg_match('~\d+,\d+~', $cat)) {
$params['cat'] = $cat;
}
$questionnode = $navigationnode->add(get_string('questionbank', 'question'),
new moodle_url('/question/edit.php', $params), navigation_node::TYPE_CONTAINER, null, 'questionbank');
$contexts = new question_edit_contexts($context);
if ($contexts->have_one_edit_tab_cap('questions')) {
$questionnode->add(get_string('questions', 'question'), new moodle_url(
'/question/edit.php', $params), navigation_node::TYPE_SETTING, null, 'questions');
}
if ($contexts->have_one_edit_tab_cap('categories')) {
$questionnode->add(get_string('categories', 'question'), new moodle_url(
'/question/category.php', $params), navigation_node::TYPE_SETTING, null, 'categories');
}
if ($contexts->have_one_edit_tab_cap('import')) {
$questionnode->add(get_string('import', 'question'), new moodle_url(
'/question/import.php', $params), navigation_node::TYPE_SETTING, null, 'import');
}
if ($contexts->have_one_edit_tab_cap('export')) {
$questionnode->add(get_string('export', 'question'), new moodle_url(
'/question/export.php', $params), navigation_node::TYPE_SETTING, null, 'export');
}
return $questionnode;
}
/**
* @return array all the capabilities that relate to accessing particular questions.
*/
function question_get_question_capabilities() {
return array(
'moodle/question:add',
'moodle/question:editmine',
'moodle/question:editall',
'moodle/question:viewmine',
'moodle/question:viewall',
'moodle/question:usemine',
'moodle/question:useall',
'moodle/question:movemine',
'moodle/question:moveall',
'moodle/question:tagmine',
'moodle/question:tagall',
);
}
/**
* @return array all the question bank capabilities.
*/
function question_get_all_capabilities() {
$caps = question_get_question_capabilities();
$caps[] = 'moodle/question:managecategory';
$caps[] = 'moodle/question:flag';
return $caps;
}
/**
* Tracks all the contexts related to the one where we are currently editing
* questions, and provides helper methods to check permissions.
*
* @copyright 2007 Jamie Pratt me@jamiep.org
* @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
*/
class question_edit_contexts {
public static $caps = array(
'editq' => array('moodle/question:add',
'moodle/question:editmine',
'moodle/question:editall',
'moodle/question:viewmine',
'moodle/question:viewall',
'moodle/question:usemine',
'moodle/question:useall',
'moodle/question:movemine',
'moodle/question:moveall'),
'questions'=>array('moodle/question:add',
'moodle/question:editmine',
'moodle/question:editall',
'moodle/question:viewmine',
'moodle/question:viewall',
'moodle/question:movemine',
'moodle/question:moveall'),
'categories'=>array('moodle/question:managecategory'),
'import'=>array('moodle/question:add'),
'export'=>array('moodle/question:viewall', 'moodle/question:viewmine'));
protected $allcontexts;
/**
* Constructor
* @param context the current context.
*/
public function __construct(context $thiscontext) {
$this->allcontexts = array_values($thiscontext->get_parent_contexts(true));
}
/**
* @return context[] all parent contexts
*/
public function all() {
return $this->allcontexts;
}
/**
* @return context lowest context which must be either the module or course context
*/
public function lowest() {
return $this->allcontexts[0];
}
/**
* @param string $cap capability
* @return context[] parent contexts having capability, zero based index
*/
public function having_cap($cap) {
$contextswithcap = array();
foreach ($this->allcontexts as $context) {
if (has_capability($cap, $context)) {
$contextswithcap[] = $context;
}
}
return $contextswithcap;
}
/**
* @param array $caps capabilities
* @return context[] parent contexts having at least one of $caps, zero based index
*/
public function having_one_cap($caps) {
$contextswithacap = array();
foreach ($this->allcontexts as $context) {
foreach ($caps as $cap) {
if (has_capability($cap, $context)) {
$contextswithacap[] = $context;
break; //done with caps loop
}
}
}
return $contextswithacap;
}
/**
* @param string $tabname edit tab name
* @return context[] parent contexts having at least one of $caps, zero based index
*/
public function having_one_edit_tab_cap($tabname) {
return $this->having_one_cap(self::$caps[$tabname]);
}
/**
* @return context[] those contexts where a user can add a question and then use it.
*/
public function having_add_and_use() {
$contextswithcap = array();
foreach ($this->allcontexts as $context) {
if (!has_capability('moodle/question:add', $context)) {
continue;
}
if (!has_any_capability(array('moodle/question:useall', 'moodle/question:usemine'), $context)) {
continue;
}
$contextswithcap[] = $context;
}
return $contextswithcap;
}
/**
* Has at least one parent context got the cap $cap?
*
* @param string $cap capability
* @return boolean
*/
public function have_cap($cap) {
return (count($this->having_cap($cap)));
}
/**
* Has at least one parent context got one of the caps $caps?
*
* @param array $caps capability
* @return boolean
*/
public function have_one_cap($caps) {
foreach ($caps as $cap) {
if ($this->have_cap($cap)) {
return true;
}
}
return false;
}
/**
* Has at least one parent context got one of the caps for actions on $tabname
*
* @param string $tabname edit tab name
* @return boolean
*/
public function have_one_edit_tab_cap($tabname) {
return $this->have_one_cap(self::$caps[$tabname]);
}
/**
* Throw error if at least one parent context hasn't got the cap $cap
*
* @param string $cap capability
*/
public function require_cap($cap) {
if (!$this->have_cap($cap)) {
print_error('nopermissions', '', '', $cap);
}
}
/**
* Throw error if at least one parent context hasn't got one of the caps $caps
*
* @param array $caps capabilities
*/
public function require_one_cap($caps) {
if (!$this->have_one_cap($caps)) {
$capsstring = join(', ', $caps);
print_error('nopermissions', '', '', $capsstring);
}
}
/**
* Throw error if at least one parent context hasn't got one of the caps $caps
*
* @param string $tabname edit tab name
*/
public function require_one_edit_tab_cap($tabname) {
if (!$this->have_one_edit_tab_cap($tabname)) {
print_error('nopermissions', '', '', 'access question edit tab '.$tabname);
}
}
}
/**
* Helps call file_rewrite_pluginfile_urls with the right parameters.
*
* @package core_question
* @category files
* @param string $text text being processed
* @param string $file the php script used to serve files
* @param int $contextid context ID
* @param string $component component
* @param string $filearea filearea
* @param array $ids other IDs will be used to check file permission
* @param int $itemid item ID
* @param array $options options
* @return string
*/
function question_rewrite_question_urls($text, $file, $contextid, $component,
$filearea, array $ids, $itemid, array $options=null) {
$idsstr = '';
if (!empty($ids)) {
$idsstr .= implode('/', $ids);
}
if ($itemid !== null) {
$idsstr .= '/' . $itemid;
}
return file_rewrite_pluginfile_urls($text, $file, $contextid, $component,
$filearea, $idsstr, $options);
}
/**
* Rewrite the PLUGINFILE urls in part of the content of a question, for use when
* viewing the question outside an attempt (for example, in the question bank
* listing or in the quiz statistics report).
*
* @param string $text the question text.
* @param int $questionid the question id.
* @param int $filecontextid the context id of the question being displayed.
* @param string $filecomponent the component that owns the file area.
* @param string $filearea the file area name.
* @param int|null $itemid the file's itemid
* @param int $previewcontextid the context id where the preview is being displayed.
* @param string $previewcomponent component responsible for displaying the preview.
* @param array $options text and file options ('forcehttps'=>false)
* @return string $questiontext with URLs rewritten.
*/
function question_rewrite_question_preview_urls($text, $questionid,
$filecontextid, $filecomponent, $filearea, $itemid,
$previewcontextid, $previewcomponent, $options = null) {
$path = "preview/$previewcontextid/$previewcomponent/$questionid";
if ($itemid) {
$path .= '/' . $itemid;
}
return file_rewrite_pluginfile_urls($text, 'pluginfile.php', $filecontextid,
$filecomponent, $filearea, $path, $options);
}
/**
* Called by pluginfile.php to serve files related to the 'question' core
* component and for files belonging to qtypes.
*
* For files that relate to questions in a question_attempt, then we delegate to
* a function in the component that owns the attempt (for example in the quiz,
* or in core question preview) to get necessary inforation.
*
* (Note that, at the moment, all question file areas relate to questions in
* attempts, so the If at the start of the last paragraph is always true.)
*
* Does not return, either calls send_file_not_found(); or serves the file.
*
* @package core_question
* @category files
* @param stdClass $course course settings object
* @param stdClass $context context object
* @param string $component the name of the component we are serving files for.
* @param string $filearea the name of the file area.
* @param array $args the remaining bits of the file path.
* @param bool $forcedownload whether the user must be forced to download the file.
* @param array $options additional options affecting the file serving
*/
function question_pluginfile($course, $context, $component, $filearea, $args, $forcedownload, array $options=array()) {
global $DB, $CFG;
// Special case, sending a question bank export.
if ($filearea === 'export') {
list($context, $course, $cm) = get_context_info_array($context->id);
require_login($course, false, $cm);
require_once($CFG->dirroot . '/question/editlib.php');
$contexts = new question_edit_contexts($context);
// check export capability
$contexts->require_one_edit_tab_cap('export');
$category_id = (int)array_shift($args);
$format = array_shift($args);
$cattofile = array_shift($args);
$contexttofile = array_shift($args);
$filename = array_shift($args);
// load parent class for import/export
require_once($CFG->dirroot . '/question/format.php');
require_once($CFG->dirroot . '/question/editlib.php');
require_once($CFG->dirroot . '/question/format/' . $format . '/format.php');
$classname = 'qformat_' . $format;
if (!class_exists($classname)) {
send_file_not_found();
}
$qformat = new $classname();
if (!$category = $DB->get_record('question_categories', array('id' => $category_id))) {
send_file_not_found();
}
$qformat->setCategory($category);
$qformat->setContexts($contexts->having_one_edit_tab_cap('export'));
$qformat->setCourse($course);
if ($cattofile == 'withcategories') {
$qformat->setCattofile(true);
} else {
$qformat->setCattofile(false);
}
if ($contexttofile == 'withcontexts') {
$qformat->setContexttofile(true);
} else {
$qformat->setContexttofile(false);
}
if (!$qformat->exportpreprocess()) {
send_file_not_found();
print_error('exporterror', 'question', $thispageurl->out());
}
// export data to moodle file pool
if (!$content = $qformat->exportprocess()) {
send_file_not_found();
}
send_file($content, $filename, 0, 0, true, true, $qformat->mime_type());
}
// Normal case, a file belonging to a question.
$qubaidorpreview = array_shift($args);
// Two sub-cases: 1. A question being previewed outside an attempt/usage.
if ($qubaidorpreview === 'preview') {
$previewcontextid = (int)array_shift($args);
$previewcomponent = array_shift($args);
$questionid = (int) array_shift($args);
$previewcontext = context_helper::instance_by_id($previewcontextid);
$result = component_callback($previewcomponent, 'question_preview_pluginfile', array(
$previewcontext, $questionid,
$context, $component, $filearea, $args,
$forcedownload, $options), 'callbackmissing');
if ($result === 'callbackmissing') {
throw new coding_exception("Component {$previewcomponent} does not define the callback " .
"{$previewcomponent}_question_preview_pluginfile callback. " .
"Which is required if you are using question_rewrite_question_preview_urls.", DEBUG_DEVELOPER);
}
send_file_not_found();
}
// 2. A question being attempted in the normal way.
$qubaid = (int)$qubaidorpreview;
$slot = (int)array_shift($args);
$module = $DB->get_field('question_usages', 'component',
array('id' => $qubaid));
if (!$module) {
send_file_not_found();
}
if ($module === 'core_question_preview') {
require_once($CFG->dirroot . '/question/previewlib.php');
return question_preview_question_pluginfile($course, $context,
$component, $filearea, $qubaid, $slot, $args, $forcedownload, $options);
} else {
$dir = core_component::get_component_directory($module);
if (!file_exists("$dir/lib.php")) {
send_file_not_found();
}
include_once("$dir/lib.php");
$filefunction = $module . '_question_pluginfile';
if (function_exists($filefunction)) {
$filefunction($course, $context, $component, $filearea, $qubaid, $slot,
$args, $forcedownload, $options);
}
// Okay, we're here so lets check for function without 'mod_'.
if (strpos($module, 'mod_') === 0) {
$filefunctionold = substr($module, 4) . '_question_pluginfile';
if (function_exists($filefunctionold)) {
$filefunctionold($course, $context, $component, $filearea, $qubaid, $slot,
$args, $forcedownload, $options);
}
}
send_file_not_found();
}
}
/**
* Serve questiontext files in the question text when they are displayed in this report.
*
* @package core_files
* @category files
* @param context $previewcontext the context in which the preview is happening.
* @param int $questionid the question id.
* @param context $filecontext the file (question) context.
* @param string $filecomponent the component the file belongs to.
* @param string $filearea the file area.
* @param array $args remaining file args.
* @param bool $forcedownload.
* @param array $options additional options affecting the file serving.
*/
function core_question_question_preview_pluginfile($previewcontext, $questionid,
$filecontext, $filecomponent, $filearea, $args, $forcedownload, $options = array()) {
global $DB;
// Verify that contextid matches the question.
$question = $DB->get_record_sql('
SELECT q.*, qc.contextid
FROM {question} q
JOIN {question_categories} qc ON qc.id = q.category
WHERE q.id = :id AND qc.contextid = :contextid',
array('id' => $questionid, 'contextid' => $filecontext->id), MUST_EXIST);
// Check the capability.
list($context, $course, $cm) = get_context_info_array($previewcontext->id);
require_login($course, false, $cm);
question_require_capability_on($question, 'use');
$fs = get_file_storage();
$relativepath = implode('/', $args);
$fullpath = "/{$filecontext->id}/{$filecomponent}/{$filearea}/{$relativepath}";
if (!$file = $fs->get_file_by_hash(sha1($fullpath)) or $file->is_directory()) {
send_file_not_found();
}
send_stored_file($file, 0, 0, $forcedownload, $options);
}
/**
* Create url for question export
*
* @param int $contextid, current context
* @param int $categoryid, categoryid
* @param string $format
* @param string $withcategories
* @param string $ithcontexts
* @param moodle_url export file url
*/
function question_make_export_url($contextid, $categoryid, $format, $withcategories,
$withcontexts, $filename) {
global $CFG;
$urlbase = "$CFG->wwwroot/pluginfile.php";
return moodle_url::make_file_url($urlbase,
"/$contextid/question/export/{$categoryid}/{$format}/{$withcategories}" .
"/{$withcontexts}/{$filename}", true);
}
/**
* Get the URL to export a single question (exportone.php).
*
* @param stdClass|question_definition $question the question definition as obtained from
* question_bank::load_question_data() or question_bank::make_question().
* (Only ->id and ->contextid are used.)
* @return moodle_url the requested URL.
*/
function question_get_export_single_question_url($question) {
$params = ['id' => $question->id, 'sesskey' => sesskey()];
$context = context::instance_by_id($question->contextid);
switch ($context->contextlevel) {
case CONTEXT_MODULE:
$params['cmid'] = $context->instanceid;
break;
case CONTEXT_COURSE:
$params['courseid'] = $context->instanceid;
break;
default:
$params['courseid'] = SITEID;
}
return new moodle_url('/question/exportone.php', $params);
}
/**
* Return a list of page types
* @param string $pagetype current page type
* @param stdClass $parentcontext Block's parent context
* @param stdClass $currentcontext Current context of block
*/
function question_page_type_list($pagetype, $parentcontext, $currentcontext) {
global $CFG;
$types = array(
'question-*'=>get_string('page-question-x', 'question'),
'question-edit'=>get_string('page-question-edit', 'question'),
'question-category'=>get_string('page-question-category', 'question'),
'question-export'=>get_string('page-question-export', 'question'),
'question-import'=>get_string('page-question-import', 'question')
);
if ($currentcontext->contextlevel == CONTEXT_COURSE) {
require_once($CFG->dirroot . '/course/lib.php');
return array_merge(course_page_type_list($pagetype, $parentcontext, $currentcontext), $types);
} else {
return $types;
}
}
/**
* Does an activity module use the question bank?
*
* @param string $modname The name of the module (without mod_ prefix).
* @return bool true if the module uses questions.
*/
function question_module_uses_questions($modname) {
if (plugin_supports('mod', $modname, FEATURE_USES_QUESTIONS)) {
return true;
}
$component = 'mod_'.$modname;
if (component_callback_exists($component, 'question_pluginfile')) {
debugging("{$component} uses questions but doesn't declare FEATURE_USES_QUESTIONS", DEBUG_DEVELOPER);
return true;
}
return false;
}
/**
* If $oldidnumber ends in some digits then return the next available idnumber of the same form.
*
* So idnum -> null (no digits at the end) idnum0099 -> idnum0100 (if that is unused,
* else whichever of idnum0101, idnume0102, ... is unused. idnum9 -> idnum10.
*
* @param string|null $oldidnumber a question idnumber, or can be null.
* @param int $categoryid a question category id.
* @return string|null suggested new idnumber for a question in that category, or null if one cannot be found.
*/
function core_question_find_next_unused_idnumber(?string $oldidnumber, int $categoryid): ?string {
global $DB;
// The the old idnumber is not of the right form, bail now.
if (!preg_match('~\d+$~', $oldidnumber, $matches)) {
return null;
}
// Find all used idnumbers in one DB query.
$usedidnumbers = $DB->get_records_select_menu('question', 'category = ? AND idnumber IS NOT NULL',
[$categoryid], '', 'idnumber, 1');
// Find the next unused idnumber.
$numberbit = 'X' . $matches[0]; // Need a string here so PHP does not do '0001' + 1 = 2.
$stem = substr($oldidnumber, 0, -strlen($matches[0]));
do {
// If we have got to something9999, insert an extra digit before incrementing.
if (preg_match('~^(.*[^0-9])(9+)$~', $numberbit, $matches)) {
$numberbit = $matches[1] . '0' . $matches[2];
}
$numberbit++;
$newidnumber = $stem . substr($numberbit, 1);
} while (isset($usedidnumbers[$newidnumber]));
return (string) $newidnumber;
}
