moodle/lib/questionlib.php

1946 lines
69 KiB
PHP

<?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 //////////////////////////////////////////////////////
/**
* Returns an array of names of activity modules that use this question
*
* @deprecated since Moodle 2.1. Use {@link questions_in_use} instead.
*
* @param object $questionid
* @return array of strings
*/
function question_list_instances($questionid) {
throw new coding_exception('question_list_instances has been deprectated. ' .
'Please use questions_in_use instead.');
}
/**
* @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) {
global $CFG;
if (question_engine::questions_in_use($questionids)) {
return true;
}
foreach (get_plugin_list('mod') as $module => $path) {
$lib = $path . '/lib.php';
if (is_readable($lib)) {
include_once($lib);
$fn = $module . '_questions_in_use';
if (function_exists($fn)) {
if ($fn($questionids)) {
return true;
}
} else {
// Fallback for legacy modules.
$fn = $module . '_question_list_instances';
if (function_exists($fn)) {
foreach ($questionids as $questionid) {
$instances = $fn($questionid);
if (!empty($instances)) {
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));
}
/**
* Returns list of 'allowed' grades for grade selection
* formatted suitably for dropdown box function
*
* @deprecated since 2.1. Use {@link question_bank::fraction_options()} or
* {@link question_bank::fraction_options_full()} instead.
*
* @return object ->gradeoptionsfull full array ->gradeoptions +ve only
*/
function get_grade_options() {
$grades = new stdClass();
$grades->gradeoptions = question_bank::fraction_options();
$grades->gradeoptionsfull = question_bank::fraction_options_full();
return $grades;
}
/**
* match grade options
* if no match return error or match nearest
* @param array $gradeoptionsfull list of valid options
* @param int $grade grade to be tested
* @param string $matchgrades 'error' or 'nearest'
* @return mixed either 'fixed' value or false if erro
*/
function match_grade_options($gradeoptionsfull, $grade, $matchgrades='error') {
if ($matchgrades == 'error') {
// if we just need an error...
foreach ($gradeoptionsfull as $value => $option) {
// slightly fuzzy test, never check floats for equality :-)
if (abs($grade - $value) < 0.00001) {
return $grade;
}
}
// didn't find a match so that's an error
return false;
} else if ($matchgrades == 'nearest') {
// work out nearest value
$hownear = array();
foreach ($gradeoptionsfull as $value => $option) {
if ($grade==$value) {
return $grade;
}
$hownear[ $value ] = abs( $grade - $value );
}
// reverse sort list of deltas and grab the last (smallest)
asort( $hownear, SORT_NUMERIC );
reset( $hownear );
return key( $hownear );
} else {
return false;
}
}
/**
* @deprecated Since Moodle 2.1. Use {@link question_category_in_use} instead.
* @param integer $categoryid a question category id.
* @param boolean $recursive whether to check child categories too.
* @return boolean whether any question in this category is in use.
*/
function question_category_isused($categoryid, $recursive = false) {
throw new coding_exception('question_category_isused has been deprectated. ' .
'Please use question_category_in_use instead.');
}
/**
* 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 by an activity module
* @param object $question The question being deleted
*/
function question_delete_question($questionid) {
global $DB;
$question = $DB->get_record_sql('
SELECT q.*, qc.contextid
FROM {question} q
JOIN {question_categories} qc ON qc.id = q.category
WHERE q.id = ?', array($questionid));
if (!$question) {
// In some situations, for example if this was a child of a
// Cloze question that was previously deleted, the question may already
// have gone. In this case, just do nothing.
return;
}
// Do not delete a question if it is used by an activity module
if (questions_in_use(array($questionid))) {
return;
}
// Check permissions.
question_require_capability_on($question, 'edit');
$dm = new question_engine_data_mapper();
$dm->delete_previews($questionid);
// delete questiontype-specific data
question_bank::get_qtype($question->qtype, false)->delete_question(
$questionid, $question->contextid);
// Now recursively delete all child questions
if ($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));
}
/**
* All question categories and their questions are deleted for this course.
*
* @param stdClass $course an object representing the activity
* @param boolean $feedback to specify if the process must output a summary of its work
* @return boolean
*/
function question_delete_course($course, $feedback=true) {
global $DB, $OUTPUT;
//To store feedback to be showed at the end of the process
$feedbackdata = array();
//Cache some strings
$strcatdeleted = get_string('unusedcategorydeleted', 'quiz');
$coursecontext = context_course::instance($course->id);
$categoriescourse = $DB->get_records('question_categories',
array('contextid' => $coursecontext->id), 'parent', 'id, parent, name, contextid');
if ($categoriescourse) {
//Sort categories following their tree (parent-child) relationships
//this will make the feedback more readable
$categoriescourse = sort_categories_by_tree($categoriescourse);
foreach ($categoriescourse as $category) {
//Delete it completely (questions and category itself)
//deleting questions
if ($questions = $DB->get_records('question',
array('category' => $category->id), '', 'id,qtype')) {
foreach ($questions as $question) {
question_delete_question($question->id);
}
$DB->delete_records("question", array("category" => $category->id));
}
//delete the category
$DB->delete_records('question_categories', array('id' => $category->id));
//Fill feedback
$feedbackdata[] = array($category->name, $strcatdeleted);
}
//Inform about changes performed if feedback is enabled
if ($feedback) {
$table = new html_table();
$table->head = array(get_string('category', 'quiz'), get_string('action'));
$table->data = $feedbackdata;
echo html_writer::table($table);
}
}
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 object $category course category object
* @param object $newcategory empty means everything deleted, otherwise id of
* category where content moved
* @param boolean $feedback to specify if the process must output a summary of its work
* @return boolean
*/
function question_delete_course_category($category, $newcategory, $feedback=true) {
global $DB, $OUTPUT;
$context = context_coursecat::instance($category->id);
if (empty($newcategory)) {
$feedbackdata = array(); // To store feedback to be showed at the end of the process
$rescueqcategory = null; // See the code around the call to question_save_from_deletion.
$strcatdeleted = get_string('unusedcategorydeleted', 'quiz');
// Loop over question categories.
if ($categories = $DB->get_records('question_categories',
array('contextid'=>$context->id), 'parent', 'id, parent, name')) {
foreach ($categories as $category) {
// Deal with any questions in the category.
if ($questions = $DB->get_records('question',
array('category' => $category->id), '', 'id,qtype')) {
// Try to delete each question.
foreach ($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 deteted. This could
// happen, for example, if questions are added to a course,
// and then that course is moved to another category (MDL-14802).
$questionids = $DB->get_records_menu('question',
array('category'=>$category->id), '', 'id, 1');
if (!empty($questionids)) {
if (!$rescueqcategory = question_save_from_deletion(
array_keys($questionids), get_parent_contextid($context),
print_context_name($context), $rescueqcategory)) {
return false;
}
$feedbackdata[] = array($category->name,
get_string('questionsmovedto', 'question', $rescueqcategory->name));
}
}
// Now delete the category.
if (!$DB->delete_records('question_categories', array('id'=>$category->id))) {
return false;
}
$feedbackdata[] = array($category->name, $strcatdeleted);
} // End loop over categories.
}
// Output feedback if requested.
if ($feedback and $feedbackdata) {
$table = new html_table();
$table->head = array(get_string('questioncategory', 'question'), get_string('action'));
$table->data = $feedbackdata;
echo html_writer::table($table);
}
} else {
// Move question categories ot the new context.
if (!$newcontext = context_coursecat::instance($newcategory->id)) {
return false;
}
$DB->set_field('question_categories', 'contextid', $newcontext->id,
array('contextid'=>$context->id));
if ($feedback) {
$a = new stdClass();
$a->oldplace = print_context_name($context);
$a->newplace = print_context_name($newcontext);
echo $OUTPUT->notification(
get_string('movedquestionsandcategories', 'question', $a), 'notifysuccess');
}
}
return true;
}
/**
* Enter description here...
*
* @param array $questionids of question ids
* @param object $newcontext 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 = 0;
$newcategory->contextid = $newcontextid;
$newcategory->name = get_string('questionsrescuedfrom', 'question', $oldplace);
$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 boolean $feedback to specify if the process must output a summary of its work
* @return boolean
*/
function question_delete_activity($cm, $feedback=true) {
global $DB, $OUTPUT;
//To store feedback to be showed at the end of the process
$feedbackdata = array();
//Cache some strings
$strcatdeleted = get_string('unusedcategorydeleted', 'quiz');
$modcontext = context_module::instance($cm->id);
if ($categoriesmods = $DB->get_records('question_categories',
array('contextid' => $modcontext->id), 'parent', 'id, parent, name, contextid')) {
//Sort categories following their tree (parent-child) relationships
//this will make the feedback more readable
$categoriesmods = sort_categories_by_tree($categoriesmods);
foreach ($categoriesmods as $category) {
//Delete it completely (questions and category itself)
//deleting questions
if ($questions = $DB->get_records('question',
array('category' => $category->id), '', 'id,qtype')) {
foreach ($questions as $question) {
question_delete_question($question->id);
}
$DB->delete_records("question", array("category"=>$category->id));
}
//delete the category
$DB->delete_records('question_categories', array('id'=>$category->id));
//Fill feedback
$feedbackdata[] = array($category->name, $strcatdeleted);
}
//Inform about changes performed if feedback is enabled
if ($feedback) {
$table = new html_table();
$table->head = array(get_string('category', 'quiz'), get_string('action'));
$table->data = $feedbackdata;
echo html_writer::table($table);
}
}
return true;
}
/**
* 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 acutally 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
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);
}
}
// 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);
// TODO Deal with datasets.
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;
$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);
}
$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 $PAGE->context.
* @return string the URL.
*/
function question_preview_url($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'] = $maxmark;
}
if (!is_null($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.
*
* @global object
* @global object
* @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 $join.
* You are strongly recommended to use named placeholder.
*
* @return array partially complete question objects. You need to call get_question_options
* on them before they can be properly used.
*/
function question_preload_questions($questionids, $extrafields = '', $join = '',
$extraparams = array()) {
global $DB;
if (empty($questionids)) {
return array();
}
if ($join) {
$join = ' JOIN '.$join;
}
if ($extrafields) {
$extrafields = ', ' . $extrafields;
}
list($questionidcondition, $params) = $DB->get_in_or_equal(
$questionids, SQL_PARAMS_NAMED, 'qid0000');
$sql = 'SELECT q.*, qc.contextid' . $extrafields . ' FROM {question} q
JOIN {question_categories} qc ON q.category = qc.id' .
$join .
' WHERE q.id ' . $questionidcondition;
// Load the questions
if (!$questions = $DB->get_records_sql($sql, $extraparams + $params)) {
return array();
}
foreach ($questions as $question) {
$question->_partiallyloaded = true;
}
// Note, a possible optimisation here would be to not load the TEXT fields
// (that is, questiontext and generalfeedback) here, and instead load them in
// question_load_questions. That would add one DB query, but reduce the amount
// of data transferred most of the time. I am not going to do this optimisation
// until it is shown to be worthwhile.
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 boolean $loadtags load the question tags from the tags table. Optional, default false.
*/
function _tidy_question($question, $loadtags = false) {
global $CFG;
if (!question_bank::is_qtype_installed($question->qtype)) {
$question->questiontext = html_writer::tag('p', get_string('warningmissingtype',
'qtype_missingtype')) . $question->questiontext;
}
question_bank::get_qtype($question->qtype)->get_question_options($question);
if (isset($question->_partiallyloaded)) {
unset($question->_partiallyloaded);
}
if ($loadtags && !empty($CFG->usetags)) {
require_once($CFG->dirroot . '/tag/lib.php');
$question->tags = tag_get_tags_array('question', $question->id);
}
}
/**
* 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 boolean $loadtags load the question tags from the tags table. Optional, default false.
* @return bool Indicates success or failure.
*/
function get_question_options(&$questions, $loadtags = false) {
if (is_array($questions)) { // deal with an array of questions
foreach ($questions as $i => $notused) {
_tidy_question($questions[$i], $loadtags);
}
} else { // deal with single question
_tidy_question($questions, $loadtags);
}
return true;
}
/**
* 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();
}
/// FUNCTIONS THAT SIMPLY WRAP QUESTIONTYPE METHODS //////////////////////////////////
/**
* Saves question options
*
* Simply calls the question type specific save_question_options() method.
*/
function save_question_options($question) {
question_bank::get_qtype($question->qtype)->save_question_options($question);
}
/// CATEGORY FUNCTIONS /////////////////////////////////////////////////////////////////
/**
* returns the categories with their names ordered following parent-child relationships
* finally it tries to return pending categories (those being orphaned, whose parent is
* incorrect) to avoid missing any category from original array.
*/
function sort_categories_by_tree(&$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('&nbsp;&nbsp;&nbsp;', $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) {
global $OUTPUT;
$categoriesarray = question_category_options($contexts, $top, $currentcat,
false, $nochildrenof);
if ($selected) {
$choose = '';
} else {
$choose = 'choosedots';
}
$options = array();
foreach ($categoriesarray as $group => $opts) {
$options[] = array($group => $opts);
}
echo html_writer::label($selected, 'menucategory', false, array('class' => 'accesshide'));
echo html_writer::select($options, 'category', $selected, $choose);
}
/**
* @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('question_categories',
array('contextid' => $contextid), 'id', '*', 0, 1);
if (!empty($category)) {
return reset($category);
} else {
return false;
}
}
/**
* 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 => $context) {
if (!$exists = $DB->record_exists("question_categories",
array('contextid' => $context->id))) {
// Otherwise, we need to make one
$category = new stdClass();
$contextname = print_context_name($context, false, true);
$category->name = get_string('defaultfor', 'question', $contextname);
$category->info = get_string('defaultinfofor', 'question', $contextname);
$category->contextid = $context->id;
$category->parent = 0;
// 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 $sortorder used as the ORDER BY clause in the select statement.
* @return array of category objects.
*/
function get_categories_for_contexts($contexts, $sortorder = 'parent, sortorder, name ASC') {
global $DB;
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)
ORDER BY $sortorder");
}
/**
* Output an array of question categories.
*/
function question_category_options($contexts, $top = false, $currentcat = 0,
$popupform = false, $nochildrenof = -1) {
global $CFG;
$pcontexts = array();
foreach ($contexts as $context) {
$pcontexts[] = $context->id;
}
$contextslist = join($pcontexts, ', ');
$categories = get_categories_for_contexts($contextslist);
$categories = question_add_context_in_key($categories);
if ($top) {
$categories = question_add_tops($categories, $pcontexts);
}
$categories = add_indented_names($categories, $nochildrenof);
// sort cats out into different contexts
$categoriesarray = array();
foreach ($pcontexts as $pcontext) {
$contextstring = print_context_name(
get_context_instance_by_id($pcontext), true, true);
foreach ($categories as $category) {
if ($category->contextid == $pcontext) {
$cid = $category->id;
if ($currentcat != $cid || $currentcat == 0) {
$countstring = !empty($category->questioncount) ?
" ($category->questioncount)" : '';
$categoriesarray[$contextstring][$cid] = $category->indentedname.$countstring;
}
}
}
}
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 $newcatarray;
}
function question_add_tops($categories, $pcontexts) {
$topcats = array();
foreach ($pcontexts as $context) {
$newcat = new stdClass();
$newcat->id = "0,$context";
$newcat->name = get_string('top');
$newcat->parent = -1;
$newcat->contextid = $context;
$topcats["0,$context"] = $newcat;
}
//put topcats in at beginning of array - they'll be sorted into different contexts later.
return array_merge($topcats, $categories);
}
/**
* @return array of question category ids of the category and all subcategories.
*/
function question_categorylist($categoryid) {
global $DB;
$subcategories = $DB->get_records('question_categories',
array('parent' => $categoryid), 'sortorder ASC', 'id, 1');
$categorylist = array($categoryid);
foreach ($subcategories as $subcategory) {
$categorylist = array_merge($categorylist, question_categorylist($subcategory->id));
}
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 = 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', $component);
}
}
collatorlib::asort($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 mixed $question object or id
* @param string $cap 'add', 'edit', 'view', 'use', 'move'
* @param integer $cachecat useful to cache all question records in a category
* @return boolean this user has the capability $cap for this question $question?
*/
function question_has_capability_on($question, $cap, $cachecat = -1) {
global $USER, $DB;
// these are capabilities on existing questions capabilties are
//set per category. Each of these has a mine and all version. Append 'mine' and 'all'
$question_questioncaps = array('edit', 'view', 'use', 'move');
static $questions = array();
static $categories = array();
static $cachedcat = array();
if ($cachecat != -1 && array_search($cachecat, $cachedcat) === false) {
$questions += $DB->get_records('question', array('category' => $cachecat), '', 'id,category,createdby');
$cachedcat[] = $cachecat;
}
if (!is_object($question)) {
if (!isset($questions[$question])) {
if (!$questions[$question] = $DB->get_record('question',
array('id' => $question), 'id,category,createdby')) {
print_error('questiondoesnotexist', 'question');
}
}
$question = $questions[$question];
}
if (empty($question->category)) {
// This can happen when we have created a fake 'missingtype' question to
// take the place of a deleted question.
return false;
}
if (!isset($categories[$question->category])) {
if (!$categories[$question->category] = $DB->get_record('question_categories',
array('id'=>$question->category))) {
print_error('invalidcategory', 'quiz');
}
}
$category = $categories[$question->category];
$context = get_context_instance_by_id($category->contextid);
if (array_search($cap, $question_questioncaps)!== false) {
if (!has_capability('moodle/question:' . $cap . 'all', $context)) {
if ($question->createdby == $USER->id) {
return has_capability('moodle/question:' . $cap . 'mine', $context);
} else {
return false;
}
} else {
return true;
}
} else {
return has_capability('moodle/question:' . $cap, $context);
}
}
/**
* Require capability on question.
*/
function question_require_capability_on($question, $cap) {
if (!question_has_capability_on($question, $cap)) {
print_error('nopermissions', '', '', $cap);
}
return true;
}
/**
* Get the real state - the correct question id and answer - for a random
* question.
* @param object $state with property answer.
* @return mixed return integer real question id or false if there was an
* error..
*/
function question_get_real_state($state) {
global $OUTPUT;
$realstate = clone($state);
$matches = array();
if (!preg_match('|^random([0-9]+)-(.*)|', $state->answer, $matches)) {
echo $OUTPUT->notification(get_string('errorrandom', 'quiz_statistics'));
return false;
} else {
$realstate->question = $matches[1];
$realstate->answer = $matches[2];
return $realstate;
}
}
/**
* @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 . ',' . $context->id . '&amp;';
}
switch ($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);
$contexts = new question_edit_contexts($context);
if ($contexts->have_one_edit_tab_cap('questions')) {
$questionnode->add(get_string('questions', 'quiz'), new moodle_url(
'/question/edit.php', $params), navigation_node::TYPE_SETTING);
}
if ($contexts->have_one_edit_tab_cap('categories')) {
$questionnode->add(get_string('categories', 'quiz'), new moodle_url(
'/question/category.php', $params), navigation_node::TYPE_SETTING);
}
if ($contexts->have_one_edit_tab_cap('import')) {
$questionnode->add(get_string('import', 'quiz'), new moodle_url(
'/question/import.php', $params), navigation_node::TYPE_SETTING);
}
if ($contexts->have_one_edit_tab_cap('export')) {
$questionnode->add(get_string('export', 'quiz'), new moodle_url(
'/question/export.php', $params), navigation_node::TYPE_SETTING);
}
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',
);
}
/**
* @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 array all parent contexts
*/
public function all() {
return $this->allcontexts;
}
/**
* @return object lowest context which must be either the module or course context
*/
public function lowest() {
return $this->allcontexts[0];
}
/**
* @param string $cap capability
* @return array parent contexts having capability, zero based index
*/
public function having_cap($cap) {
$contextswithcap = array();
foreach ($this->allcontexts as $context) {
if (has_capability($cap, $context)) {
$contextswithcap[] = $context;
}
}
return $contextswithcap;
}
/**
* @param array $caps capabilities
* @return array 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 array 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 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 $cap capabilities
*/
public function require_one_cap($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 the questiontext, when viewing the question
* text outside and attempt (for example, in the question bank listing or in the
* quiz statistics report).
*
* @param string $questiontext the question text.
* @param int $contextid the context the text is being displayed in.
* @param string $component component
* @param array $ids other IDs will be used to check file permission
* @param array $options
* @return string $questiontext with URLs rewritten.
*/
function question_rewrite_questiontext_preview_urls($questiontext, $contextid,
$component, $questionid, $options=null) {
return file_rewrite_pluginfile_urls($questiontext, 'pluginfile.php', $contextid,
'question', 'questiontext_preview', "$component/$questionid", $options);
}
/**
* Send a file from the question text of a question.
* @param int $questionid the question id
* @param array $args the remaining file arguments (file path).
* @param bool $forcedownload whether the user must be forced to download the file.
* @param array $options additional options affecting the file serving
*/
function question_send_questiontext_file($questionid, $args, $forcedownload, $options) {
global $DB;
$question = $DB->get_record_sql('
SELECT q.id, qc.contextid
FROM {question} q
JOIN {question_categories} qc ON qc.id = q.category
WHERE q.id = :id', array('id' => $questionid), MUST_EXIST);
$fs = get_file_storage();
$fullpath = "/$question->contextid/question/questiontext/$question->id/" . implode('/', $args);
if (!$file = $fs->get_file_by_hash(sha1($fullpath)) or $file->is_directory()) {
send_file_not_found();
}
send_stored_file($file, 0, 0, $forcedownload, $options);
}
/**
* 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, $CFG;
if ($filearea === 'questiontext_preview') {
$component = array_shift($args);
$questionid = array_shift($args);
component_callback($component, 'questiontext_preview_pluginfile', array(
$context, $questionid, $args, $forcedownload, $options));
send_file_not_found();
}
list($context, $course, $cm) = get_context_info_array($context->id);
require_login($course, false, $cm);
if ($filearea === 'export') {
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 = $qformat->exportprocess(true)) {
send_file_not_found();
}
send_file($content, $filename, 0, 0, true, true, $qformat->mime_type());
}
$qubaid = (int)array_shift($args);
$slot = (int)array_shift($args);
$module = $DB->get_field('question_usages', 'component',
array('id' => $qubaid));
if ($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 {
$dir = get_component_directory($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 stdClass $context the context
* @param int $questionid the question id
* @param array $args remaining file args
* @param bool $forcedownload
* @param array $options additional options affecting the file serving
*/
function core_question_questiontext_preview_pluginfile($context, $questionid, $args, $forcedownload, array $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' => $context->id), MUST_EXIST);
// Check the capability.
list($context, $course, $cm) = get_context_info_array($context->id);
require_login($course, false, $cm);
question_require_capability_on($question, 'use');
question_send_questiontext_file($questionid, $args, $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->httpswwwroot/pluginfile.php";
return moodle_url::make_file_url($urlbase,
"/$contextid/question/export/{$categoryid}/{$format}/{$withcategories}" .
"/{$withcontexts}/{$filename}", true);
}
/**
* 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;
}
}