moodle/mod/quiz/lib.php
2007-01-09 09:07:16 +00:00

711 lines
24 KiB
PHP

<?php // $Id$
/**
* Library of functions for the quiz module.
*
* This contains functions that are called also from outside the quiz module
* Functions that are only called by the quiz module itself are in {@link locallib.php}
* @version $Id$
* @author Martin Dougiamas and many others.
* @license http://www.gnu.org/copyleft/gpl.html GNU Public License
* @package quiz
*/
require_once($CFG->libdir.'/pagelib.php');
require_once($CFG->libdir.'/questionlib.php');
/// CONSTANTS ///////////////////////////////////////////////////////////////////
/**#@+
* The different review options are stored in the bits of $quiz->review
* These constants help to extract the options
*/
/**
* The first 6 bits refer to the time immediately after the attempt
*/
define('QUIZ_REVIEW_IMMEDIATELY', 0x3f);
/**
* the next 6 bits refer to the time after the attempt but while the quiz is open
*/
define('QUIZ_REVIEW_OPEN', 0xfc0);
/**
* the final 6 bits refer to the time after the quiz closes
*/
define('QUIZ_REVIEW_CLOSED', 0x3f000);
// within each group of 6 bits we determine what should be shown
define('QUIZ_REVIEW_RESPONSES', 1*0x1041); // Show responses
define('QUIZ_REVIEW_SCORES', 2*0x1041); // Show scores
define('QUIZ_REVIEW_FEEDBACK', 4*0x1041); // Show feedback
define('QUIZ_REVIEW_ANSWERS', 8*0x1041); // Show correct answers
// Some handling of worked solutions is already in the code but not yet fully supported
// and not switched on in the user interface.
define('QUIZ_REVIEW_SOLUTIONS', 16*0x1041); // Show solutions
define('QUIZ_REVIEW_GENERALFEEDBACK', 32*0x1041); // Show general feedback
/**#@-*/
/**
* If start and end date for the quiz are more than this many seconds apart
* they will be represented by two separate events in the calendar
*/
define("QUIZ_MAX_EVENT_LENGTH", "432000"); // 5 days maximum
/// FUNCTIONS ///////////////////////////////////////////////////////////////////
/**
* Given an object containing all the necessary data,
* (defined by the form in mod.html) this function
* will create a new instance and return the id number
* of the new instance.
*
* @param object $quiz the data that came from the form.
* @return mixed the id of the new instance on success,
* false or a string error message on failure.
*/
function quiz_add_instance($quiz) {
// Process the options from the form.
$quiz->created = time();
$quiz->questions = '';
$result = quiz_process_options($quiz);
if ($result && is_string($result)) {
return $result;
}
// Try to store it in the database.
if (!$quiz->id = insert_record("quiz", $quiz)) {
return false;
}
// Do the processing required after an add or an update.
quiz_after_add_or_update($quiz);
return $quiz->id;
}
/**
* Given an object containing all the necessary data,
* (defined by the form in mod.html) this function
* will update an existing instance with new data.
*
* @param object $quiz the data that came from the form.
* @return mixed true on success, false or a string error message on failure.
*/
function quiz_update_instance($quiz) {
// Process the options from the form.
$result = quiz_process_options($quiz);
if ($result && is_string($result)) {
return $result;
}
// Update the database.
$quiz->id = $quiz->instance;
if (!update_record("quiz", $quiz)) {
return false; // some error occurred
}
// Do the processing required after an add or an update.
quiz_after_add_or_update($quiz);
// Delete any previous preview attempts
delete_records('quiz_attempts', 'preview', '1', 'quiz', $quiz->id);
return true;
}
function quiz_delete_instance($id) {
/// Given an ID of an instance of this module,
/// this function will permanently delete the instance
/// and any data that depends on it.
if (! $quiz = get_record("quiz", "id", "$id")) {
return false;
}
$result = true;
if ($attempts = get_records("quiz_attempts", "quiz", "$quiz->id")) {
foreach ($attempts as $attempt) {
// TODO: this should use the delete_attempt($attempt->uniqueid) function in questionlib.php
if (! delete_records("question_states", "attempt", "$attempt->uniqueid")) {
$result = false;
}
if (! delete_records("question_sessions", "attemptid", "$attempt->uniqueid")) {
$result = false;
}
}
}
$tables_to_purge = array(
'quiz_attempts' => 'quiz',
'quiz_grades' => 'quiz',
'quiz_question_instances' => 'quiz',
'quiz_grades' => 'quiz',
'quiz_feedback' => 'quizid',
'quiz' => 'id'
);
foreach ($tables_to_purge as $table => $keyfield) {
if (!delete_records($table, $keyfield, $quiz->id)) {
$result = false;
}
}
$pagetypes = page_import_types('mod/quiz/');
foreach($pagetypes as $pagetype) {
if(!delete_records('block_instance', 'pageid', $quiz->id, 'pagetype', $pagetype)) {
$result = false;
}
}
if ($events = get_records_select('event', "modulename = 'quiz' and instance = '$quiz->id'")) {
foreach($events as $event) {
delete_event($event->id);
}
}
return $result;
}
function quiz_user_outline($course, $user, $mod, $quiz) {
/// Return a small object with summary information about what a
/// user has done with a given particular instance of this module
/// Used for user activity reports.
/// $return->time = the time they did it
/// $return->info = a short text description
if ($grade = get_record('quiz_grades', 'userid', $user->id, 'quiz', $quiz->id)) {
$result = new stdClass;
if ((float)$grade->grade) {
$result->info = get_string('grade').':&nbsp;'.round($grade->grade, $quiz->decimalpoints);
}
$result->time = $grade->timemodified;
return $result;
}
return NULL;
}
function quiz_user_complete($course, $user, $mod, $quiz) {
/// Print a detailed representation of what a user has done with
/// a given particular instance of this module, for user activity reports.
if ($attempts = get_records_select('quiz_attempts', "userid='$user->id' AND quiz='$quiz->id'", 'attempt ASC')) {
if ($quiz->grade and $quiz->sumgrades && $grade = get_record('quiz_grades', 'userid', $user->id, 'quiz', $quiz->id)) {
echo get_string('grade').': '.round($grade->grade, $quiz->decimalpoints).'/'.$quiz->grade.'<br />';
}
foreach ($attempts as $attempt) {
echo get_string('attempt', 'quiz').' '.$attempt->attempt.': ';
if ($attempt->timefinish == 0) {
print_string('unfinished');
} else {
echo round($attempt->sumgrades, $quiz->decimalpoints).'/'.$quiz->sumgrades;
}
echo ' - '.userdate($attempt->timemodified).'<br />';
}
} else {
print_string('noattempts', 'quiz');
}
return true;
}
function quiz_cron () {
/// Function to be run periodically according to the moodle cron
/// This function searches for things that need to be done, such
/// as sending out mail, toggling flags etc ...
global $CFG;
return true;
}
function quiz_grades($quizid) {
/// Must return an array of grades, indexed by user, and a max grade.
$quiz = get_record('quiz', 'id', intval($quizid));
if (empty($quiz) || empty($quiz->grade)) {
return NULL;
}
$return = new stdClass;
$return->grades = get_records_menu('quiz_grades', 'quiz', $quiz->id, '', 'userid, grade');
$return->maxgrade = get_field('quiz', 'grade', 'id', $quiz->id);
return $return;
}
function quiz_get_participants($quizid) {
/// Returns an array of users who have data in a given quiz
/// (users with records in quiz_attempts and quiz_question_versions)
global $CFG;
//Get users from attempts
$us_attempts = get_records_sql("SELECT DISTINCT u.id, u.id
FROM {$CFG->prefix}user u,
{$CFG->prefix}quiz_attempts a
WHERE a.quiz = '$quizid' and
u.id = a.userid");
//Get users from question_versions
$us_versions = get_records_sql("SELECT DISTINCT u.id, u.id
FROM {$CFG->prefix}user u,
{$CFG->prefix}quiz_question_versions v
WHERE v.quiz = '$quizid' and
u.id = v.userid");
//Add us_versions to us_attempts
if ($us_versions) {
foreach ($us_versions as $us_version) {
$us_attempts[$us_version->id] = $us_version;
}
}
//Return us_attempts array (it contains an array of unique users)
return ($us_attempts);
}
function quiz_refresh_events($courseid = 0) {
// This horrible function only seems to be called from mod/quiz/db/[dbtype].php.
// This standard function will check all instances of this module
// and make sure there are up-to-date events created for each of them.
// If courseid = 0, then every quiz event in the site is checked, else
// only quiz events belonging to the course specified are checked.
// This function is used, in its new format, by restore_refresh_events()
if ($courseid == 0) {
if (! $quizzes = get_records("quiz")) {
return true;
}
} else {
if (! $quizzes = get_records("quiz", "course", $courseid)) {
return true;
}
}
$moduleid = get_field('modules', 'id', 'name', 'quiz');
foreach ($quizzes as $quiz) {
$event = NULL;
$event2 = NULL;
$event2old = NULL;
if ($events = get_records_select('event', "modulename = 'quiz' AND instance = '$quiz->id' ORDER BY timestart")) {
$event = array_shift($events);
if (!empty($events)) {
$event2old = array_shift($events);
if (!empty($events)) {
foreach ($events as $badevent) {
delete_records('event', 'id', $badevent->id);
}
}
}
}
$event->name = addslashes($quiz->name);
$event->description = addslashes($quiz->intro);
$event->courseid = $quiz->course;
$event->groupid = 0;
$event->userid = 0;
$event->modulename = 'quiz';
$event->instance = $quiz->id;
$event->visible = instance_is_visible('quiz', $quiz);
$event->timestart = $quiz->timeopen;
$event->eventtype = 'open';
$event->timeduration = ($quiz->timeclose - $quiz->timeopen);
if ($event->timeduration > QUIZ_MAX_EVENT_LENGTH) { /// Set up two events
$event2 = $event;
$event->name = addslashes($quiz->name).' ('.get_string('quizopens', 'quiz').')';
$event->timeduration = 0;
$event2->name = addslashes($quiz->name).' ('.get_string('quizcloses', 'quiz').')';
$event2->timestart = $quiz->timeclose;
$event2->eventtype = 'close';
$event2->timeduration = 0;
if (empty($event2old->id)) {
unset($event2->id);
add_event($event2);
} else {
$event2->id = $event2old->id;
update_event($event2);
}
} else if (!empty($event2->id)) {
delete_event($event2->id);
}
if (empty($event->id)) {
add_event($event);
} else {
update_event($event);
}
}
return true;
}
function quiz_get_recent_mod_activity(&$activities, &$index, $sincetime, $courseid, $quiz="0", $user="", $groupid="") {
// Returns all quizzes since a given time. If quiz is specified then
// this restricts the results
global $CFG;
if ($quiz) {
$quizselect = " AND cm.id = '$quiz'";
} else {
$quizselect = "";
}
if ($user) {
$userselect = " AND u.id = '$user'";
} else {
$userselect = "";
}
$quizzes = get_records_sql("SELECT qa.*, q.name, u.firstname, u.lastname, u.picture,
q.course, q.sumgrades as maxgrade, cm.instance, cm.section
FROM {$CFG->prefix}quiz_attempts qa,
{$CFG->prefix}quiz q,
{$CFG->prefix}user u,
{$CFG->prefix}course_modules cm
WHERE qa.timefinish > '$sincetime'
AND qa.userid = u.id $userselect
AND qa.quiz = q.id $quizselect
AND cm.instance = q.id
AND cm.course = '$courseid'
AND q.course = cm.course
ORDER BY qa.timefinish ASC");
if (empty($quizzes))
return;
foreach ($quizzes as $quiz) {
if (empty($groupid) || groups_is_member($groupid, $quiz->userid)) {
$tmpactivity = new Object;
$tmpactivity->type = "quiz";
$tmpactivity->defaultindex = $index;
$tmpactivity->instance = $quiz->quiz;
$tmpactivity->name = $quiz->name;
$tmpactivity->section = $quiz->section;
$tmpactivity->content->attemptid = $quiz->id;
$tmpactivity->content->sumgrades = $quiz->sumgrades;
$tmpactivity->content->maxgrade = $quiz->maxgrade;
$tmpactivity->content->attempt = $quiz->attempt;
$tmpactivity->user->userid = $quiz->userid;
$tmpactivity->user->fullname = fullname($quiz);
$tmpactivity->user->picture = $quiz->picture;
$tmpactivity->timestamp = $quiz->timefinish;
$activities[] = $tmpactivity;
$index++;
}
}
return;
}
function quiz_print_recent_mod_activity($activity, $course, $detail=false) {
global $CFG;
echo '<table border="0" cellpadding="3" cellspacing="0">';
echo "<tr><td class=\"forumpostpicture\" width=\"35\" valign=\"top\">";
print_user_picture($activity->user->userid, $course, $activity->user->picture);
echo "</td><td style=\"width:100%;\"><font size=\"2\">";
if ($detail) {
echo "<img src=\"$CFG->modpixpath/$activity->type/icon.gif\" ".
"class=\"icon\" alt=\"$activity->type\" /> ";
echo "<a href=\"$CFG->wwwroot/mod/quiz/view.php?id=" . $activity->instance . "\">"
. format_string($activity->name,true) . "</a> - ";
}
if (has_capability('mod/quiz:grade', get_context_instance(CONTEXT_MODULE, $course))) {
$grades = "(" . $activity->content->sumgrades . " / " . $activity->content->maxgrade . ") ";
echo "<a href=\"$CFG->wwwroot/mod/quiz/review.php?q="
. $activity->instance . "&amp;attempt="
. $activity->content->attemptid . "\">" . $grades . "</a> ";
echo get_string("attempt", "quiz") . " - " . $activity->content->attempt . "<br />";
}
echo "<a href=\"$CFG->wwwroot/user/view.php?id="
. $activity->user->userid . "&amp;course=$course\">"
. $activity->user->fullname . "</a> ";
echo " - " . userdate($activity->timestamp);
echo "</font></td></tr>";
echo "</table>";
return;
}
/**
* Pre-process the quiz options form data, making any necessary adjustments.
*
* @param object $quiz The variables set on the form.
*/
function quiz_process_options(&$quiz) {
$quiz->timemodified = time();
// Quiz open time.
if (empty($quiz->timeopen)) {
$quiz->preventlate = 0;
}
// Quiz name. (Make up a default if one was not given.)
if (empty($quiz->name)) {
if (empty($quiz->intro)) {
$quiz->name = get_string('modulename', 'quiz');
} else {
$quiz->name = shorten_text(strip_tags($quiz->intro));
}
}
$quiz->name = trim($quiz->name);
// Time limit. (Get rid of it if the checkbox was not ticked.)
if (empty($quiz->timelimitenable)) {
$quiz->timelimit = 0;
}
$quiz->timelimit = round($quiz->timelimit);
// Quiz feedback
// Clean up the boundary text.
for ($i = 0; $i < count($quiz->feedbacktext); $i += 1) {
if (empty($quiz->feedbacktext[$i])) {
$quiz->feedbacktext[$i] = '';
} else {
$quiz->feedbacktext[$i] = trim($quiz->feedbacktext[$i]);
}
}
// Check the boundary value is a number or a percentage, and in range.
$i = 0;
while (!empty($quiz->feedbackboundaries[$i])) {
$boundary = trim($quiz->feedbackboundaries[$i]);
if (!is_numeric($boundary)) {
if (strlen($boundary) > 0 && $boundary[strlen($boundary) - 1] == '%') {
$boundary = trim(substr($boundary, 0, -1));
if (is_numeric($boundary)) {
$boundary = $boundary * $quiz->grade / 100.0;
} else {
return get_string('feedbackerrorboundaryformat', 'quiz', $i + 1);
}
}
}
if ($boundary <= 0 || $boundary >= $quiz->grade) {
return get_string('feedbackerrorboundaryoutofrange', 'quiz', $i + 1);
}
if ($i > 0 && $boundary >= $quiz->feedbackboundaries[$i - 1]) {
return get_string('feedbackerrororder', 'quiz', $i + 1);
}
$quiz->feedbackboundaries[$i] = $boundary;
$i += 1;
}
$numboundaries = $i;
// Check there is nothing in the remaining unused fields.
for ($i = $numboundaries; $i < count($quiz->feedbackboundaries); $i += 1) {
if (!empty($quiz->feedbackboundaries[$i]) && trim($quiz->feedbackboundaries[$i]) != '') {
return get_string('feedbackerrorjunkinboundary', 'quiz', $i + 1);
}
}
for ($i = $numboundaries + 1; $i < count($quiz->feedbacktext); $i += 1) {
if (!empty($quiz->feedbacktext[$i]) && trim($quiz->feedbacktext[$i]) != '') {
return get_string('feedbackerrorjunkinfeedback', 'quiz', $i + 1);
}
}
$quiz->feedbackboundaries[-1] = $quiz->grade + 1; // Needs to be bigger than $quiz->grade because of '<' test in quiz_feedback_for_grade().
$quiz->feedbackboundaries[$numboundaries] = 0;
$quiz->feedbackboundarycount = $numboundaries;
// Settings that get combined to go into the optionflags column.
$quiz->optionflags = 0;
if (!empty($quiz->adaptive)) {
$quiz->optionflags |= QUESTION_ADAPTIVE;
}
// Settings that get combined to go into the review column.
$review = 0;
if (isset($quiz->responsesimmediately)) {
$review += (QUIZ_REVIEW_RESPONSES & QUIZ_REVIEW_IMMEDIATELY);
unset($quiz->responsesimmediately);
}
if (isset($quiz->responsesopen)) {
$review += (QUIZ_REVIEW_RESPONSES & QUIZ_REVIEW_OPEN);
unset($quiz->responsesopen);
}
if (isset($quiz->responsesclosed)) {
$review += (QUIZ_REVIEW_RESPONSES & QUIZ_REVIEW_CLOSED);
unset($quiz->responsesclosed);
}
if (isset($quiz->scoreimmediately)) {
$review += (QUIZ_REVIEW_SCORES & QUIZ_REVIEW_IMMEDIATELY);
unset($quiz->scoreimmediately);
}
if (isset($quiz->scoreopen)) {
$review += (QUIZ_REVIEW_SCORES & QUIZ_REVIEW_OPEN);
unset($quiz->scoreopen);
}
if (isset($quiz->scoreclosed)) {
$review += (QUIZ_REVIEW_SCORES & QUIZ_REVIEW_CLOSED);
unset($quiz->scoreclosed);
}
if (isset($quiz->feedbackimmediately)) {
$review += (QUIZ_REVIEW_FEEDBACK & QUIZ_REVIEW_IMMEDIATELY);
unset($quiz->feedbackimmediately);
}
if (isset($quiz->feedbackopen)) {
$review += (QUIZ_REVIEW_FEEDBACK & QUIZ_REVIEW_OPEN);
unset($quiz->feedbackopen);
}
if (isset($quiz->feedbackclosed)) {
$review += (QUIZ_REVIEW_FEEDBACK & QUIZ_REVIEW_CLOSED);
unset($quiz->feedbackclosed);
}
if (isset($quiz->answersimmediately)) {
$review += (QUIZ_REVIEW_ANSWERS & QUIZ_REVIEW_IMMEDIATELY);
unset($quiz->answersimmediately);
}
if (isset($quiz->answersopen)) {
$review += (QUIZ_REVIEW_ANSWERS & QUIZ_REVIEW_OPEN);
unset($quiz->answersopen);
}
if (isset($quiz->answersclosed)) {
$review += (QUIZ_REVIEW_ANSWERS & QUIZ_REVIEW_CLOSED);
unset($quiz->answersclosed);
}
if (isset($quiz->solutionsimmediately)) {
$review += (QUIZ_REVIEW_SOLUTIONS & QUIZ_REVIEW_IMMEDIATELY);
unset($quiz->solutionsimmediately);
}
if (isset($quiz->solutionsopen)) {
$review += (QUIZ_REVIEW_SOLUTIONS & QUIZ_REVIEW_OPEN);
unset($quiz->solutionsopen);
}
if (isset($quiz->solutionsclosed)) {
$review += (QUIZ_REVIEW_SOLUTIONS & QUIZ_REVIEW_CLOSED);
unset($quiz->solutionsclosed);
}
if (isset($quiz->generalfeedbackimmediately)) {
$review += (QUIZ_REVIEW_GENERALFEEDBACK & QUIZ_REVIEW_IMMEDIATELY);
unset($quiz->solutionsimmediately);
}
if (isset($quiz->generalfeedbackopen)) {
$review += (QUIZ_REVIEW_GENERALFEEDBACK & QUIZ_REVIEW_OPEN);
unset($quiz->solutionsopen);
}
if (isset($quiz->generalfeedbackclosed)) {
$review += (QUIZ_REVIEW_GENERALFEEDBACK & QUIZ_REVIEW_CLOSED);
unset($quiz->solutionsclosed);
}
$quiz->review = $review;
}
/**
* This function is called at the end of quiz_add_instance
* and quiz_update_instance, to do the common processing.
*
* @param object $quiz the quiz object.
*/
function quiz_after_add_or_update($quiz) {
// Save the feedback
delete_records('quiz_feedback', 'quizid', $quiz->id);
for ($i = 0; $i <= $quiz->feedbackboundarycount; $i += 1) {
$feedback = new stdClass;
$feedback->quizid = $quiz->id;
$feedback->feedbacktext = $quiz->feedbacktext[$i];
$feedback->mingrade = $quiz->feedbackboundaries[$i];
$feedback->maxgrade = $quiz->feedbackboundaries[$i - 1];
if (!insert_record('quiz_feedback', $feedback, false)) {
return "Could not save quiz feedback.";
}
}
// Update the events relating to this quiz.
// This is slightly inefficient, deleting the old events and creating new ones. However,
// there are at most two events, and this keeps the code simpler.
if ($events = get_records_select('event', "modulename = 'quiz' and instance = '$quiz->id'")) {
foreach($events as $event) {
delete_event($event->id);
}
}
$event = new stdClass;
$event->description = $quiz->intro;
$event->courseid = $quiz->course;
$event->groupid = 0;
$event->userid = 0;
$event->modulename = 'quiz';
$event->instance = $quiz->id;
$event->timestart = $quiz->timeopen;
$event->timeduration = $quiz->timeclose - $quiz->timeopen;
$event->visible = instance_is_visible('quiz', $quiz);
$event->eventtype = 'open';
if ($quiz->timeclose and $quiz->timeopen and $event->timeduration <= QUIZ_MAX_EVENT_LENGTH) {
// Single event for the whole quiz.
$event->name = $quiz->name;
add_event($event);
} else {
// Separate start and end events.
$event->timeduration = 0;
if ($quiz->timeopen) {
$event->name = $quiz->name.' ('.get_string('quizopens', 'quiz').')';
add_event($event);
unset($event->id); // So we can use the same object for the close event.
}
if ($quiz->timeclose) {
$event->name = $quiz->name.' ('.get_string('quizcloses', 'quiz').')';
$event->timestart = $quiz->timeclose;
$event->eventtype = 'close';
add_event($event);
}
}
}
function quiz_get_view_actions() {
return array('view','view all','report');
}
function quiz_get_post_actions() {
return array('attempt','editquestions','review','submit');
}
/**
* Returns an array of names of quizzes that use this question
*
* TODO: write this
* @param object $questionid
* @return array of strings
*/
function quiz_question_list_instances($questionid) {
return array();
}
?>