moodle/lib/grade/grade_grade.php
2010-05-21 18:57:05 +00:00

807 lines
27 KiB
PHP

<?php
///////////////////////////////////////////////////////////////////////////
// //
// NOTICE OF COPYRIGHT //
// //
// Moodle - Modular Object-Oriented Dynamic Learning Environment //
// http://moodle.com //
// //
// Copyright (C) 1999 onwards Martin Dougiamas http://dougiamas.com //
// //
// This program 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 2 of the License, or //
// (at your option) any later version. //
// //
// This program 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: //
// //
// http://www.gnu.org/copyleft/gpl.html //
// //
///////////////////////////////////////////////////////////////////////////
require_once('grade_object.php');
class grade_grade extends grade_object {
/**
* The DB table.
* @var string $table
*/
public $table = 'grade_grades';
/**
* Array of required table fields, must start with 'id'.
* @var array $required_fields
*/
public $required_fields = array('id', 'itemid', 'userid', 'rawgrade', 'rawgrademax', 'rawgrademin',
'rawscaleid', 'usermodified', 'finalgrade', 'hidden', 'locked',
'locktime', 'exported', 'overridden', 'excluded', 'timecreated', 'timemodified');
/**
* Array of optional fields with default values (these should match db defaults)
* @var array $optional_fields
*/
public $optional_fields = array('feedback'=>null, 'feedbackformat'=>0, 'information'=>null, 'informationformat'=>0);
/**
* The id of the grade_item this grade belongs to.
* @var int $itemid
*/
public $itemid;
/**
* The grade_item object referenced by $this->itemid.
* @var object $grade_item
*/
public $grade_item;
/**
* The id of the user this grade belongs to.
* @var int $userid
*/
public $userid;
/**
* The grade value of this raw grade, if such was provided by the module.
* @var float $rawgrade
*/
public $rawgrade;
/**
* The maximum allowable grade when this grade was created.
* @var float $rawgrademax
*/
public $rawgrademax = 100;
/**
* The minimum allowable grade when this grade was created.
* @var float $rawgrademin
*/
public $rawgrademin = 0;
/**
* id of the scale, if this grade is based on a scale.
* @var int $rawscaleid
*/
public $rawscaleid;
/**
* The userid of the person who last modified this grade.
* @var int $usermodified
*/
public $usermodified;
/**
* The final value of this grade.
* @var float $finalgrade
*/
public $finalgrade;
/**
* 0 if visible, 1 always hidden or date not visible until
* @var float $hidden
*/
public $hidden = 0;
/**
* 0 not locked, date when the item was locked
* @var float locked
*/
public $locked = 0;
/**
* 0 no automatic locking, date when to lock the grade automatically
* @var float $locktime
*/
public $locktime = 0;
/**
* Exported flag
* @var boolean $exported
*/
public $exported = 0;
/**
* Overridden flag
* @var boolean $overridden
*/
public $overridden = 0;
/**
* Grade excluded from aggregation functions
* @var boolean $excluded
*/
public $excluded = 0;
/**
* TODO: HACK: create a new field datesubmitted - the date of submission if any
* @var boolean $timecreated
*/
public $timecreated = null;
/**
* TODO: HACK: create a new field dategraded - the date of grading
* @var boolean $timemodified
*/
public $timemodified = null;
/**
* Returns array of grades for given grade_item+users.
* @param object $grade_item
* @param array $userids
* @param bool $include_missing include grades that do not exist yet
* @return array userid=>grade_grade array
*/
public function fetch_users_grades($grade_item, $userids, $include_missing=true) {
global $DB;
// hmm, there might be a problem with length of sql query
// if there are too many users requested - we might run out of memory anyway
$limit = 2000;
$count = count($userids);
if ($count > $limit) {
$half = (int)($count/2);
$first = array_slice($userids, 0, $half);
$second = array_slice($userids, $half);
return grade_grade::fetch_users_grades($grade_item, $first, $include_missing) + grade_grade::fetch_users_grades($grade_item, $second, $include_missing);
}
list($user_ids_cvs, $params) = $DB->get_in_or_equal($userids, SQL_PARAMS_NAMED, 'uid0');
$params['giid'] = $grade_item->id;
$result = array();
if ($grade_records = $DB->get_records_select('grade_grades', "itemid=:giid AND userid $user_ids_cvs", $params)) {
foreach ($grade_records as $record) {
$result[$record->userid] = new grade_grade($record, false);
}
}
if ($include_missing) {
foreach ($userids as $userid) {
if (!array_key_exists($userid, $result)) {
$grade_grade = new grade_grade();
$grade_grade->userid = $userid;
$grade_grade->itemid = $grade_item->id;
$result[$userid] = $grade_grade;
}
}
}
return $result;
}
/**
* Loads the grade_item object referenced by $this->itemid and saves it as $this->grade_item for easy access.
* @return object grade_item.
*/
public function load_grade_item() {
if (empty($this->itemid)) {
debugging('Missing itemid');
$this->grade_item = null;
return null;
}
if (empty($this->grade_item)) {
$this->grade_item = grade_item::fetch(array('id'=>$this->itemid));
} else if ($this->grade_item->id != $this->itemid) {
debugging('Itemid mismatch');
$this->grade_item = grade_item::fetch(array('id'=>$this->itemid));
}
return $this->grade_item;
}
/**
* Is grading object editable?
* @return boolean
*/
public function is_editable() {
if ($this->is_locked()) {
return false;
}
$grade_item = $this->load_grade_item();
if ($grade_item->gradetype == GRADE_TYPE_NONE) {
return false;
}
return true;
}
/**
* Check grade lock status. Uses both grade item lock and grade lock.
* Internally any date in locked field (including future ones) means locked,
* the date is stored for logging purposes only.
*
* @return boolean true if locked, false if not
*/
public function is_locked() {
$this->load_grade_item();
if (empty($this->grade_item)) {
return !empty($this->locked);
} else {
return !empty($this->locked) or $this->grade_item->is_locked();
}
}
/**
* Checks if grade overridden
* @return boolean
*/
public function is_overridden() {
return !empty($this->overridden);
}
/**
* Returns timestamp of submission related to this grade,
* might be null if not submitted.
* @return int
*/
public function get_datesubmitted() {
//TODO: HACK - create new fields in 2.0
return $this->timecreated;
}
/**
* Returns timestamp when last graded,
* might be null if no grade present.
* @return int
*/
public function get_dategraded() {
//TODO: HACK - create new fields in 2.0
if (is_null($this->finalgrade) and is_null($this->feedback)) {
return null; // no grade == no date
} else if ($this->overridden) {
return $this->overridden;
} else {
return $this->timemodified;
}
}
/**
* Set the overridden status of grade
* @param boolean $state requested overridden state
* @param boolean $refresh refresh grades from external activities if needed
* @return boolean true is db state changed
*/
public function set_overridden($state, $refresh = true) {
if (empty($this->overridden) and $state) {
$this->overridden = time();
$this->update();
return true;
} else if (!empty($this->overridden) and !$state) {
$this->overridden = 0;
$this->update();
if ($refresh) {
//refresh when unlocking
$this->grade_item->refresh_grades($this->userid);
}
return true;
}
return false;
}
/**
* Checks if grade excluded from aggregation functions
* @return boolean
*/
public function is_excluded() {
return !empty($this->excluded);
}
/**
* Set the excluded status of grade
* @param boolean $state requested excluded state
* @return boolean true is db state changed
*/
public function set_excluded($state) {
if (empty($this->excluded) and $state) {
$this->excluded = time();
$this->update();
return true;
} else if (!empty($this->excluded) and !$state) {
$this->excluded = 0;
$this->update();
return true;
}
return false;
}
/**
* Lock/unlock this grade.
*
* @param int $locked 0, 1 or a timestamp int(10) after which date the item will be locked.
* @param boolean $cascade ignored param
* @param boolean $refresh refresh grades when unlocking
* @return boolean true if successful, false if can not set new lock state for grade
*/
public function set_locked($lockedstate, $cascade=false, $refresh=true) {
$this->load_grade_item();
if ($lockedstate) {
if ($this->grade_item->needsupdate) {
//can not lock grade if final not calculated!
return false;
}
$this->locked = time();
$this->update();
return true;
} else {
if (!empty($this->locked) and $this->locktime < time()) {
//we have to reset locktime or else it would lock up again
$this->locktime = 0;
}
// remove the locked flag
$this->locked = 0;
$this->update();
if ($refresh and !$this->is_overridden()) {
//refresh when unlocking and not overridden
$this->grade_item->refresh_grades($this->userid);
}
return true;
}
}
/**
* Lock the grade if needed - make sure this is called only when final grades are valid
* @param array $items array of all grade item ids
* @return void
*/
public function check_locktime_all($items) {
global $CFG, $DB;
$now = time(); // no rounding needed, this is not supposed to be called every 10 seconds
list($usql, $params) = $DB->get_in_or_equal($items);
$params[] = $now;
if ($rs = $DB->get_recordset_select('grade_grades', "itemid $usql AND locked = 0 AND locktime > 0 AND locktime < ?", $params)) {
foreach ($rs as $grade) {
$grade_grade = new grade_grade($grade, false);
$grade_grade->locked = time();
$grade_grade->update('locktime');
}
$rs->close();
}
}
/**
* Set the locktime for this grade.
*
* @param int $locktime timestamp for lock to activate
* @return void
*/
public function set_locktime($locktime) {
$this->locktime = $locktime;
$this->update();
}
/**
* Set the locktime for this grade.
*
* @return int $locktime timestamp for lock to activate
*/
public function get_locktime() {
$this->load_grade_item();
$item_locktime = $this->grade_item->get_locktime();
if (empty($this->locktime) or ($item_locktime and $item_locktime < $this->locktime)) {
return $item_locktime;
} else {
return $this->locktime;
}
}
/**
* Check grade hidden status. Uses data from both grade item and grade.
* @return boolean true if hidden, false if not
*/
public function is_hidden() {
$this->load_grade_item();
if (empty($this->grade_item)) {
return $this->hidden == 1 or ($this->hidden != 0 and $this->hidden > time());
} else {
return $this->hidden == 1 or ($this->hidden != 0 and $this->hidden > time()) or $this->grade_item->is_hidden();
}
}
/**
* Check grade hidden status. Uses data from both grade item and grade.
* @return boolean true if hiddenuntil, false if not
*/
public function is_hiddenuntil() {
$this->load_grade_item();
if ($this->hidden == 1 or $this->grade_item->hidden == 1) {
return false; //always hidden
}
if ($this->hidden > 1 or $this->grade_item->hidden > 1) {
return true;
}
return false;
}
/**
* Check grade hidden status. Uses data from both grade item and grade.
* @return int 0 means visible, 1 hidden always, timestamp hidden until
*/
public function get_hidden() {
$this->load_grade_item();
$item_hidden = $this->grade_item->get_hidden();
if ($item_hidden == 1) {
return 1;
} else if ($item_hidden == 0) {
return $this->hidden;
} else {
if ($this->hidden == 0) {
return $item_hidden;
} else if ($this->hidden == 1) {
return 1;
} else if ($this->hidden > $item_hidden) {
return $this->hidden;
} else {
return $item_hidden;
}
}
}
/**
* Set the hidden status of grade, 0 mean visible, 1 always hidden, number means date to hide until.
* @param boolean $cascade ignored
* @param int $hidden new hidden status
*/
public function set_hidden($hidden, $cascade=false) {
$this->hidden = $hidden;
$this->update();
}
/**
* Finds and returns a grade_grade instance based on params.
* @static
*
* @param array $params associative arrays varname=>value
* @return object grade_grade instance or false if none found.
*/
public static function fetch($params) {
return grade_object::fetch_helper('grade_grades', 'grade_grade', $params);
}
/**
* Finds and returns all grade_grade instances based on params.
* @static
*
* @param array $params associative arrays varname=>value
* @return array array of grade_grade instances or false if none found.
*/
public static function fetch_all($params) {
return grade_object::fetch_all_helper('grade_grades', 'grade_grade', $params);
}
/**
* Given a float value situated between a source minimum and a source maximum, converts it to the
* corresponding value situated between a target minimum and a target maximum. Thanks to Darlene
* for the formula :-)
*
* @static
* @param float $rawgrade
* @param float $source_min
* @param float $source_max
* @param float $target_min
* @param float $target_max
* @return float Converted value
*/
public static function standardise_score($rawgrade, $source_min, $source_max, $target_min, $target_max) {
if (is_null($rawgrade)) {
return null;
}
if ($source_max == $source_min or $target_min == $target_max) {
// prevent division by 0
return $target_max;
}
$factor = ($rawgrade - $source_min) / ($source_max - $source_min);
$diff = $target_max - $target_min;
$standardised_value = $factor * $diff + $target_min;
return $standardised_value;
}
/**
* Return array of grade item ids that are either hidden or indirectly depend
* on hidden grades, excluded grades are not returned.
* THIS IS A REALLY BIG HACK! to be replaced by conditional aggregation of hidden grades in 2.0
*
* @static
* @param array $grades all course grades of one user, & used for better internal caching
* @param array $items $grade_items array of grade items, & used for better internal caching
* @return array
*/
public static function get_hiding_affected(&$grade_grades, &$grade_items) {
global $CFG;
if (count($grade_grades) !== count($grade_items)) {
print_error('invalidarraysize', 'debug', '', 'grade_grade::get_hiding_affected()!');
}
$dependson = array();
$todo = array();
$unknown = array(); // can not find altered
$altered = array(); // altered grades
$hiddenfound = false;
foreach($grade_grades as $itemid=>$unused) {
$grade_grade =& $grade_grades[$itemid];
if ($grade_grade->is_excluded()) {
//nothing to do, aggregation is ok
} else if ($grade_grade->is_hidden()) {
$hiddenfound = true;
$altered[$grade_grade->itemid] = null;
} else if ($grade_grade->is_locked() or $grade_grade->is_overridden()) {
// no need to recalculate locked or overridden grades
} else {
$dependson[$grade_grade->itemid] = $grade_items[$grade_grade->itemid]->depends_on();
if (!empty($dependson[$grade_grade->itemid])) {
$todo[] = $grade_grade->itemid;
}
}
}
if (!$hiddenfound) {
return array('unknown'=>array(), 'altered'=>array());
}
$max = count($todo);
$hidden_precursors = null;
for($i=0; $i<$max; $i++) {
$found = false;
foreach($todo as $key=>$do) {
$hidden_precursors = array_intersect($dependson[$do], $unknown);
if ($hidden_precursors) {
// this item depends on hidden grade indirectly
$unknown[$do] = $do;
unset($todo[$key]);
$found = true;
continue;
} else if (!array_intersect($dependson[$do], $todo)) {
$hidden_precursors = array_intersect($dependson[$do], array_keys($altered));
if (!$hidden_precursors) {
// hiding does not affect this grade
unset($todo[$key]);
$found = true;
continue;
} else {
// depends on altered grades - we should try to recalculate if possible
if ($grade_items[$do]->is_calculated() or
(!$grade_items[$do]->is_category_item() and !$grade_items[$do]->is_course_item())
) {
$unknown[$do] = $do;
unset($todo[$key]);
$found = true;
continue;
} else {
$grade_category = $grade_items[$do]->load_item_category();
$values = array();
foreach ($dependson[$do] as $itemid) {
if (array_key_exists($itemid, $altered)) {
//nulling an altered precursor
$values[$itemid] = $altered[$itemid];
} elseif (empty($values[$itemid])) {
$values[$itemid] = $grade_grades[$itemid]->finalgrade;
}
}
foreach ($values as $itemid=>$value) {
if ($grade_grades[$itemid]->is_excluded()) {
unset($values[$itemid]);
continue;
}
$values[$itemid] = grade_grade::standardise_score($value, $grade_items[$itemid]->grademin, $grade_items[$itemid]->grademax, 0, 1);
}
if ($grade_category->aggregateonlygraded) {
foreach ($values as $itemid=>$value) {
if (is_null($value)) {
unset($values[$itemid]);
}
}
} else {
foreach ($values as $itemid=>$value) {
if (is_null($value)) {
$values[$itemid] = 0;
}
}
}
// limit and sort
$grade_category->apply_limit_rules($values, $grade_items);
asort($values, SORT_NUMERIC);
// let's see we have still enough grades to do any statistics
if (count($values) == 0) {
// not enough attempts yet
$altered[$do] = null;
unset($todo[$key]);
$found = true;
continue;
}
$agg_grade = $grade_category->aggregate_values($values, $grade_items);
// recalculate the rawgrade back to requested range
$finalgrade = grade_grade::standardise_score($agg_grade, 0, 1, $grade_items[$do]->grademin, $grade_items[$do]->grademax);
$finalgrade = $grade_items[$do]->bounded_grade($finalgrade);
$altered[$do] = $finalgrade;
unset($todo[$key]);
$found = true;
continue;
}
}
}
}
if (!$found) {
break;
}
}
return array('unknown'=>$unknown, 'altered'=>$altered);
}
/**
* Returns true if the grade's value is superior or equal to the grade item's gradepass value, false otherwise.
* @param object $grade_item An optional grade_item of which gradepass value we can use, saves having to load the grade_grade's grade_item
* @return boolean
*/
public function is_passed($grade_item = null) {
if (empty($grade_item)) {
if (!isset($this->grade_item)) {
$this->load_grade_item();
}
} else {
$this->grade_item = $grade_item;
$this->itemid = $grade_item->id;
}
// Return null if finalgrade is null
if (is_null($this->finalgrade)) {
return null;
}
// Return null if gradepass == grademin or gradepass is null
if (is_null($this->grade_item->gradepass) || $this->grade_item->gradepass == $this->grade_item->grademin) {
return null;
}
return $this->finalgrade >= $this->grade_item->gradepass;
}
public function insert($source=null) {
// TODO: dategraded hack - do not update times, they are used for submission and grading
//$this->timecreated = $this->timemodified = time();
return parent::insert($source);
}
/**
* In addition to update() as defined in grade_object rounds the float numbers using php function,
* the reason is we need to compare the db value with computed number to skip updates if possible.
* @param string $source from where was the object inserted (mod/forum, manual, etc.)
* @return boolean success
*/
public function update($source=null) {
$this->rawgrade = grade_floatval($this->rawgrade);
$this->finalgrade = grade_floatval($this->finalgrade);
$this->rawgrademin = grade_floatval($this->rawgrademin);
$this->rawgrademax = grade_floatval($this->rawgrademax);
return parent::update($source);
}
/**
* Used to notify the completion system (if necessary) that a user's grade
* has changed, and clear up a possible score cache.
* @param bool deleted True if grade was actually deleted
*/
function notify_changed($deleted) {
global $USER, $SESSION, $CFG,$COURSE, $DB;
// Grades may be cached in user session
if ($USER->id == $this->userid) {
unset($SESSION->gradescorecache[$this->itemid]);
}
// Ignore during restore
// TODO There should be a proper way to determine when we are in restore
// so that this hack looking for a $restore global is not needed.
global $restore;
if (!empty($restore->backup_unique_code)) {
return;
}
require_once($CFG->libdir.'/completionlib.php');
// Bail out immediately if completion is not enabled for site (saves loading
// grade item below)
if (!completion_info::is_enabled_for_site()) {
return;
}
// Load information about grade item
$this->load_grade_item();
// Only course-modules have completion data
if ($this->grade_item->itemtype!='mod') {
return;
}
// Use $COURSE if available otherwise get it via item fields
if(!empty($COURSE) && $COURSE->id == $this->grade_item->courseid) {
$course = $COURSE;
} else {
$course = $DB->get_record('course', array('id'=>$this->grade_item->courseid));
}
// Bail out if completion is not enabled for course
$completion = new completion_info($course);
if (!$completion->is_enabled()) {
return;
}
// Get course-module
$cm = get_coursemodule_from_instance($this->grade_item->itemmodule,
$this->grade_item->iteminstance, $this->grade_item->courseid);
if (!$cm) {
debugging("Couldn't find course-module for module
'{$this->grade_item->itemmodule}', instance '{$this->grade_item->iteminstance}',
course '{$this->grade_item->courseid}'");
return;
}
// Pass information on to completion system
$completion->inform_grade_changed($cm, $this->grade_item, $this, $deleted);
}
}