moodle/lib/grade/grade_category.php
2007-06-18 15:29:20 +00:00

961 lines
34 KiB
PHP

<?php // $Id$
///////////////////////////////////////////////////////////////////////////
// //
// NOTICE OF COPYRIGHT //
// //
// Moodle - Modular Object-Oriented Dynamic Learning Environment //
// http://moodle.com //
// //
// Copyright (C) 2001-2003 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_category extends grade_object {
/**
* The DB table.
* @var string $table
*/
var $table = 'grade_categories';
/**
* Array of class variables that are not part of the DB table fields
* @var array $nonfields
*/
var $nonfields = array('table', 'nonfields', 'children', 'all_children');
/**
* The course this category belongs to.
* @var int $courseid
*/
var $courseid;
/**
* The category this category belongs to (optional).
* @var int $parent
*/
var $parent;
/**
* The grade_category object referenced by $this->parent (PK).
* @var object $parent_category
*/
var $parent_category;
/**
* A grade_category object this category used to belong to before getting updated. Will be deleted shortly.
* @var object $old_parent
*/
var $old_parent;
/**
* The number of parents this category has.
* @var int $depth
*/
var $depth = 0;
/**
* Shows the hierarchical path for this category as /1/2/3 (like course_categories), the last number being
* this category's autoincrement ID number.
* @var string $path
*/
var $path;
/**
* The name of this category.
* @var string $fullname
*/
var $fullname;
/**
* A constant pointing to one of the predefined aggregation strategies (none, mean, median, sum etc) .
* @var int $aggregation
*/
var $aggregation;
/**
* Keep only the X highest items.
* @var int $keephigh
*/
var $keephigh;
/**
* Drop the X lowest items.
* @var int $droplow
*/
var $droplow;
/**
* Array of grade_items or grade_categories nested exactly 1 level below this category
* @var array $children
*/
var $children;
/**
* A hierarchical array of all children below this category. This is stored separately from
* $children because it is more memory-intensive and may not be used as often.
* @var array $all_children
*/
var $all_children;
/**
* An associated grade_item object, with itemtype=category, used to calculate and cache a set of grade values
* for this category.
* @var object $grade_item
*/
var $grade_item;
/**
* Constructor. Extends the basic functionality defined in grade_object.
* @param array $params Can also be a standard object.
* @param boolean $fetch Whether or not to fetch the corresponding row from the DB.
* @param object $grade_item The associated grade_item object can be passed during construction.
*/
function grade_category($params=NULL, $fetch=true) {
$this->grade_object($params, $fetch);
$this->path = grade_category::build_path($this);
}
/**
* Builds this category's path string based on its parents (if any) and its own id number.
* This is typically done just before inserting this object in the DB for the first time,
* or when a new parent is added or changed. It is a recursive function: once the calling
* object no longer has a parent, the path is complete.
*
* @static
* @param object $grade_category
* @return int The depth of this category (2 means there is one parent)
*/
function build_path($grade_category) {
if (empty($grade_category->parent)) {
return "/$grade_category->id";
} else {
$parent = get_record('grade_categories', 'id', $grade_category->parent);
return grade_category::build_path($parent) . "/$grade_category->id";
}
}
/**
* Finds and returns a grade_category object based on 1-3 field values.
*
* @param string $field1
* @param string $value1
* @param string $field2
* @param string $value2
* @param string $field3
* @param string $value3
* @param string $fields
* @return object grade_category object or false if none found.
*/
function fetch($field1, $value1, $field2='', $value2='', $field3='', $value3='', $fields="*") {
if ($grade_category = get_record('grade_categories', $field1, $value1, $field2, $value2, $field3, $value3, $fields)) {
if (isset($this) && get_class($this) == 'grade_category') {
foreach ($grade_category as $param => $value) {
$this->$param = $value;
}
return $this;
} else {
$grade_category = new grade_category($grade_category);
return $grade_category;
}
} else {
return false;
}
}
/**
* In addition to update() as defined in grade_object, call flag_for_update of parent categories, if applicable.
*/
function update() {
$qualifies = $this->qualifies_for_update();
// Update the grade_item's sortorder if needed
if (!empty($this->sortorder)) {
$this->load_grade_item();
if (!empty($this->grade_item)) {
$this->grade_item->sortorder = $this->sortorder;
$this->grade_item->update();
}
unset($this->sortorder);
}
$result = parent::update();
// Use $this->path to update all parent categories
if ($result && $qualifies) {
$this->flag_for_update();
}
return $result;
}
/**
* If parent::delete() is successful, send flag_for_update message to parent category.
* @return boolean Success or failure.
*/
function delete() {
$result = parent::delete();
if ($result) {
$this->load_parent_category();
if (!empty($this->parent_category)) {
$result = $result && $this->parent_category->flag_for_update();
}
// Update children's categoryid/parent field
global $db;
$set_field_result = set_field('grade_items', 'categoryid', null, 'categoryid', $this->id);
$set_field_result = set_field('grade_categories', 'parent', null, 'parent', $this->id);
}
return $result;
}
/**
* In addition to the normal insert() defined in grade_object, this method sets the depth
* and path for this object, and update the record accordingly. The reason why this must
* be done here instead of in the constructor, is that they both need to know the record's
* id number, which only gets created at insertion time.
* This method also creates an associated grade_item if this wasn't done during construction.
*/
function insert() {
if (!parent::insert()) {
debugging("Could not insert this category: " . print_r($this, true));
return false;
}
$this->path = grade_category::build_path($this);
// Build path and depth variables
if (!empty($this->parent)) {
$this->depth = $this->get_depth_from_path();
} else {
$this->depth = 1;
}
$this->update();
// initialize grade_item for this category
$this->grade_item = $this->get_grade_item();
// Notify parent category of need to update.
$this->load_parent_category();
if (!empty($this->parent_category)) {
if (!$this->parent_category->flag_for_update()) {
debugging("Could not notify parent category of the need to update its final grades.");
return false;
}
}
return true;
}
/**
* Compares the values held by this object with those of the matching record in DB, and returns
* whether or not these differences are sufficient to justify an update of all parent objects.
* This assumes that this object has an id number and a matching record in DB. If not, it will return false.
* @return boolean
*/
function qualifies_for_update() {
if (empty($this->id)) {
return false;
}
$db_item = new grade_category(array('id' => $this->id));
$aggregationdiff = $db_item->aggregation != $this->aggregation;
$keephighdiff = $db_item->keephigh != $this->keephigh;
$droplowdiff = $db_item->droplow != $this->droplow;
if ($aggregationdiff || $keephighdiff || $droplowdiff) {
return true;
} else {
return false;
}
}
/**
* Sets this category's and its parent's grade_item.needsupdate to true.
* This is triggered whenever any change in any lower level may cause grade_finals
* for this category to require an update. The flag needs to be propagated up all
* levels until it reaches the top category. This is then used to determine whether or not
* to regenerate the raw and final grades for each category grade_item. This is accomplished
* thanks to the path variable, so we don't need to use recursion.
* @return boolean Success or failure
*/
function flag_for_update() {
if (empty($this->id)) {
debugging("Needsupdate requested before insering grade category.");
return true;
}
$result = true;
$this->load_grade_item();
$paths = explode('/', $this->path);
// Remove the first index, which is always empty
unset($paths[0]);
if (!empty($paths)) {
$wheresql = '';
foreach ($paths as $categoryid) {
$wheresql .= "iteminstance = $categoryid OR ";
}
$wheresql = substr($wheresql, 0, strrpos($wheresql, 'OR'));
$grade_items = set_field_select('grade_items', 'needsupdate', '1', $wheresql . ' AND courseid = ' . $this->courseid);
$this->grade_item->update_from_db();
}
return $result;
}
/**
* Generates and saves raw_grades, based on this category's immediate children, then uses the
* associated grade_item to generate matching final grades. These immediate children must first have their own
* raw and final grades, which means that ultimately we must get grade_items as children. The category's aggregation
* method is used to generate these raw grades, which can then be used by the category's associated grade_item
* to apply calculations to and generate final grades.
*
* This function must be use ONLY from grade_item::update_final_grade(),
* because the calculation must be done in correct order!!
* Steps to follow:
* 1. Get final grades from immediate children (if the children are categories, get the final grades from their grade_item)
* 3. Aggregate these grades
* 4. Save them under $this->grade_item->grade_grades_raw
*/
function generate_grades() {
global $CFG;
$grade_item = $this->get_grade_item();
if ($grade_item->gradetype == GRADE_TYPE_SCALE) {
$grade_item->load_scale();
}
$dependson = $grade_item->dependson();
$items = array();
foreach($dependson as $dep) {
$items[$dep] = grade_item::fetch('id', $dep);
}
// where to look for final grades
$gis = implode(',', array_merge($dependson, array($grade_item->id)));
$sql = "SELECT f.*
FROM {$CFG->prefix}grade_grades_final f, {$CFG->prefix}grade_items gi
WHERE gi.id = f.itemid AND gi.courseid={$grade_item->courseid} AND gi.id IN ($gis)
ORDER BY f.userid";
if ($rs = get_recordset_sql($sql)) {
if ($rs->RecordCount() > 0) {
$prevuser = 0;
$grades = array();
while ($subfinal = rs_fetch_next_record($rs)) {
if ($subfinal->userid != $prevuser) {
$this->aggregate_grades($prevuser, $items, $grades, $grade_item, $dependson);
$prevuser = $subfinal->userid;
$grades = array();
}
$grades[$subfinal->itemid] = $subfinal->gradevalue;
}
$this->aggregate_grades($prevuser, $items, $grades, $grade_item, $dependson);
}
}
//TODO: set grade to null for raw grades that do not have corresponding final grade
// using left join
return true;
}
/**
* internal function for vategory grades aggregation
*/
function aggregate_grades($userid, $items, $grades, &$grade_item, $dependson) {
if (empty($userid)) {
return;
}
// remove the final item we used to get all existing final grades of this category
unset($grades[$grade_item->id]);
if (empty($grades) or empty($items) or ($grade_item->gradetype != GRADE_TYPE_VALUE and $grade_item->gradetype != GRADE_TYPE_SCALE)) {
// no grading
if ($raw = grade_grades_raw::fetch('itemid', $grade_item->id, 'userid', $userid)) {
$raw->gradevalue = null;
$raw->update();
}
return;
}
// normalize the grades first - all will have value 0...1
foreach ($grades as $k=>$v) {
if (is_null($v)) {
// null means no grade
unset($grades[$k]);
continue;
}
$grades[$k] = standardise_score($v, $items[$k]->grademin, $items[$k]->grademax, 0, 1);
}
//sort and limit
$this->apply_limit_rules($grades);
sort($grades, SORT_NUMERIC);
if (count($grades) == 0) {
// no grading yet
if ($raw = grade_grades_raw::fetch('itemid', $grade_item->id, 'userid', $userid)) {
$raw->gradevalue = null;
$raw->update();
}
return;
}
switch ($this->aggregation) {
case GRADE_AGGREGATE_MEDIAN: // Middle point value in the set: ignores frequencies
$num = count($grades);
$halfpoint = intval($num / 2);
if($num % 2 == 0) {
$gradevalue = ($grades[ceil($halfpoint)] + $grades[floor($halfpoint)]) / 2;
} else {
$gradevalue = $grades[$halfpoint];
}
break;
case GRADE_AGGREGATE_MIN:
$gradevalue = reset($grades);
break;
case GRADE_AGGREGATE_MAX:
$gradevalue = array_pop($grades);
break;
case GRADE_AGGREGATE_MEAN_ALL: // Arithmetic average of all grade items including even NULLs; NULL grade caunted as minimum
$num = count($dependson); // you can calculate sum from this one if you multiply it with count($this->dependson() ;-)
$sum = array_sum($grades);
$gradevalue = $sum / $num;
break;
case GRADE_AGGREGATE_MODE: // the most common value, the highest one if multimode
$freq = array_count_values($grades);
arsort($freq); // sort by frequency keeping keys
$top = reset($freq); // highest frequency count
$modes = array_keys($freq, $top); // search for all modes (have the same highest count)
rsort($modes, SORT_NUMERIC); // get highes mode
$gradevalue = reset($modes);
case GRADE_AGGREGATE_MEAN_GRADED: // Arithmetic average of all final grades, unfinished are not calculated
$num = count($grades);
$sum = array_sum($grades);
$gradevalue = $sum / $num;
default:
break;
}
$raw = new grade_grades_raw(array('itemid'=>$grade_item->id, 'userid'=>$userid));
$raw->gradevalue = $gradevalue;
$raw->gradetype = $grade_item->gradetype;
$raw->scaleid = $grade_item->scaleid;
$raw->grademin = 0;
$raw->grademax = 1;
// recalculate the gradevalue bvack to requested range
$raw->gradevalue = $grade_item->adjust_grade($raw);
$raw->grademin = $grade_item->grademin;
$raw->grademax = $grade_item->grademax;
if ($raw->id) {
$raw->update();
} else {
$raw->insert();
}
}
/**
* Given an array of grade values (numerical indices), applies droplow or keephigh
* rules to limit the final array.
* @param array $grades
* @return array Limited grades.
*/
function apply_limit_rules(&$grades) {
rsort($grades, SORT_NUMERIC);
if (!empty($this->droplow)) {
for ($i = 0; $i < $this->droplow; $i++) {
array_pop($grades);
}
} elseif (!empty($this->keephigh)) {
while (count($grades) > $this->keephigh) {
array_pop($grades);
}
}
}
/**
* Given an array of stdClass children of a certain $object_type, returns a flat or nested
* array of these children, ready for appending to a tree built by get_children.
* @static
* @param array $children
* @param string $arraytype
* @param string $object_type
* @return array
*/
function children_to_array($children, $arraytype='nested', $object_type='grade_item') {
$children_array = array();
foreach ($children as $id => $child) {
$child = new $object_type($child, false);
if ($arraytype == 'nested') {
$children_array[$child->get_sortorder()] = array('object' => $child);
} else {
$children_array[$child->get_sortorder()] = $child;
}
}
return $children_array;
}
/**
* Returns true if this category has any child grade_category or grade_item.
* @return int number of direct children, or false if none found.
*/
function has_children() {
return count_records('grade_categories', 'parent', $this->id) + count_records('grade_items', 'categoryid', $this->id);
}
/**
* Checks whether an existing child exists for this category. If the new child is of a
* different type, the method will return false (not allowed). Otherwise it will return true.
* @param object $child This must be a complete object, not a stdClass
* @return boolean Success or failure
*/
function can_add_child($child) {
if ($this->has_children()) {
if (get_class($child) != $this->get_childrentype()) {
return false;
} else {
return true;
}
} else {
return true;
}
}
/**
* Disassociates this category from its category parent(s). The object is then updated in DB.
* @return boolean Success or Failure
*/
function divorce_parent() {
$this->old_parent = $this->get_parent_category();
$this->parent = null;
$this->parent_category = null;
$this->depth = 1;
$this->path = '/' . $this->id;
return $this->update();
}
/**
* Looks at a path string (e.g. /2/45/56) and returns the depth level represented by this path (in this example, 3).
* If no string is given, it looks at the obect's path and assigns the resulting depth to its $depth variable.
* @param string $path
* @return int Depth level
*/
function get_depth_from_path($path=NULL) {
if (empty($path)) {
$path = $this->path;
}
preg_match_all('/\/([0-9]+)+?/', $path, $matches);
$depth = count($matches[0]);
return $depth;
}
/**
* Fetches and returns all the children categories and/or grade_items belonging to this category.
* By default only returns the immediate children (depth=1), but deeper levels can be requested,
* as well as all levels (0). The elements are indexed by sort order.
* @param int $depth 1 for immediate children, 0 for all children, and 2+ for specific levels deeper than 1.
* @param string $arraytype Either 'nested' or 'flat'. A nested array represents the true hierarchy, but is more difficult to work with.
* @return array Array of child objects (grade_category and grade_item).
*/
function get_children($depth=1, $arraytype='nested') {
$children_array = array();
// Set up $depth for recursion
$newdepth = $depth;
if ($depth > 1) {
$newdepth--;
}
$childrentype = $this->get_childrentype();
if ($childrentype == 'grade_item') {
$children = get_records('grade_items', 'categoryid', $this->id);
// No need to proceed with recursion
$children_array = $this->children_to_array($children, $arraytype, 'grade_item');
$this->children = $this->children_to_array($children, 'flat', 'grade_item');
} elseif ($childrentype == 'grade_category') {
$children = get_records('grade_categories', 'parent', $this->id, 'id');
if ($depth == 1) {
$children_array = $this->children_to_array($children, $arraytype, 'grade_category');
$this->children = $this->children_to_array($children, 'flat', 'grade_category');
} else {
foreach ($children as $id => $child) {
$cat = new grade_category($child, false);
if ($cat->has_children()) {
if ($arraytype == 'nested') {
$children_array[$cat->get_sortorder()] = array('object' => $cat, 'children' => $cat->get_children($newdepth, $arraytype));
} else {
$children_array[$cat->get_sortorder()] = $cat;
$cat_children = $cat->get_children($newdepth, $arraytype);
foreach ($cat_children as $id => $cat_child) {
$children_array[$cat_child->get_sortorder()] = new grade_category($cat_child, false);
}
}
} else {
if ($arraytype == 'nested') {
$children_array[$cat->get_sortorder()] = array('object' => $cat);
} else {
$children_array[$cat->get_sortorder()] = $cat;
}
}
}
}
} else {
return null;
}
return $children_array;
}
/**
* Check the type of the first child of this category, to see whether it is a
* grade_category or a grade_item, and returns that type as a string (get_class).
* @return string
*/
function get_childrentype() {
if (empty($this->children)) {
$count_item_children = count_records('grade_items', 'categoryid', $this->id);
$count_cat_children = count_records('grade_categories', 'parent', $this->id);
if ($count_item_children > 0) {
return 'grade_item';
} elseif ($count_cat_children > 0) {
return 'grade_category';
} else {
return null;
}
}
reset($this->children);
return get_class(current($this->children));
}
/**
* Uses get_grade_item to load or create a grade_item, then saves it as $this->grade_item.
* @return object Grade_item
*/
function load_grade_item() {
$this->grade_item = $this->get_grade_item();
return $this->grade_item;
}
/**
* Retrieves from DB and instantiates the associated grade_item object.
* If no grade_item exists yet, create one.
* @return object Grade_item
*/
function get_grade_item() {
if (empty($this->id)) {
debugging("Attempt to obtain a grade_category's associated grade_item without the category's ID being set.");
return false;
}
$grade_item = new grade_item(array('courseid'=>$this->courseid, 'itemtype'=>'category', 'iteminstance'=>$this->id), false);
if (!$grade_items = $grade_item->fetch_all_using_this()) {
// create a new one
$grade_item->gradetype = GRADE_TYPE_VALUE;
$grade_item->insert();
} else if (count($grade_items) == 1){
// found existing one
$grade_item = reset($grade_items);
} else {
debugging("Found more than one grade_item attached to category id:".$this->id);
return false;
}
return $grade_item;
}
/**
* Uses $this->parent to instantiate $this->parent_category based on the
* referenced record in the DB.
* @return object Parent_category
*/
function load_parent_category() {
if (empty($this->parent_category) && !empty($this->parent)) {
$this->parent_category = $this->get_parent_category();
}
return $this->parent_category;
}
/**
* Uses $this->parent to instantiate and return a grade_category object.
* @return object Parent_category
*/
function get_parent_category() {
if (!empty($this->parent)) {
$parent_category = new grade_category(array('id' => $this->parent));
return $parent_category;
} else {
return null;
}
}
/**
* Sets this category as the parent for the given children. If the category's courseid isn't set, it uses that of the children items.
* A number of constraints are necessary:
* - The children must all be of the same type and at the same level
* - The children cannot already be top categories
* - The children all belong to the same course
* @param array $children An array of fully instantiated grade_category OR grade_item objects
*
* @return boolean Success or Failure
* @TODO big problem of performance
*/
function set_as_parent($children) {
global $CFG;
if (empty($children) || !is_array($children)) {
debugging("Passed an empty or non-array variable to grade_category::set_as_parent()");
return false;
}
// Check type and sortorder of first child
$first_child = current($children);
$first_child_type = get_class($first_child);
// If this->courseid is not set, set it to the first child's courseid
if (empty($this->courseid)) {
$this->courseid = $first_child->courseid;
}
$grade_tree = new grade_tree();
foreach ($children as $child) {
if (get_class($child) != $first_child_type) {
debugging("Violated constraint: Attempted to set a category as a parent over children of 2 different types.");
return false;
}
if ($grade_tree->get_element_type($child) == 'topcat') {
debugging("Violated constraint: Attempted to set a category over children which are already top categories.");
return false;
}
if ($first_child_type == 'grade_category' or $first_child_type == 'grade_item') {
if (!empty($child->parent)) {
debugging("Violated constraint: Attempted to set a category over children that already have a top category.");
return false;
}
} else {
debugging("Attempted to set a category over children that are neither grade_items nor grade_categories.");
return false;
}
if ($child->courseid != $this->courseid) {
debugging("Attempted to set a category over children which do not belong to the same course.");
return false;
}
}
// We passed all the checks, time to set the category as a parent.
foreach ($children as $child) {
$child->divorce_parent();
$child->set_parent_id($this->id);
if (!$child->update()) {
debugging("Could not set this category as a parent for one of its children, DB operation failed.");
return false;
}
}
// TODO Assign correct sortorders to the newly assigned children and parent. Simply add 1 to all of them!
$this->load_grade_item();
$this->grade_item->sortorder = $first_child->get_sortorder();
if (!$this->update()) {
debugging("Could not update this category's sortorder in DB.");
return false;
}
$query = "UPDATE {$CFG->prefix}grade_items SET sortorder = sortorder + 1 WHERE sortorder >= {$this->grade_item->sortorder}";
$query .= " AND courseid = $this->courseid";
if (!execute_sql($query)) {
debugging("Could not update the sortorder of grade_items listed after this category.");
return false;
} else {
return true;
}
}
/**
* Returns the most descriptive field for this object. This is a standard method used
* when we do not know the exact type of an object.
* @return string name
*/
function get_name() {
return $this->fullname;
}
/**
* Returns this category's grade_item's id. This is specified for cases where we do not
* know an object's type, and want to get either an item's id or a category's item's id.
*
* @return int
*/
function get_item_id() {
$this->load_grade_item();
return $this->grade_item->id;
}
/**
* Returns this category's parent id. A generic method shared by objects that have a parent id of some kind.
* @return id $parentid
*/
function get_parent_id() {
return $this->parent;
}
/**
* Sets this category's parent id. A generic method shared by objects that have a parent id of some kind.
* @param id $parentid
*/
function set_parent_id($parentid) {
$this->parent = $parentid;
$this->path = grade_category::build_path($this);
$this->depth = $this->get_depth_from_path();
}
/**
* Returns the sortorder of the associated grade_item. This method is also available in
* grade_item, for cases where the object type is not known.
* @return int Sort order
*/
function get_sortorder() {
if (empty($this->sortorder)) {
$this->load_grade_item();
if (!empty($this->grade_item)) {
return $this->grade_item->sortorder;
}
} else {
return $this->sortorder;
}
}
/**
* Sets a temporary sortorder variable for this category. It is used in the update() method to update the grade_item.
* This method is also available in grade_item, for cases where the object type is not know.
* @param int $sortorder
* @return void
*/
function set_sortorder($sortorder) {
$this->sortorder = $sortorder;
}
/**
* Returns the locked state/date of the associated grade_item. This method is also available in
* grade_item, for cases where the object type is not known.
* @return int 0, 1 or timestamp int(10)
*/
function get_locked() {
$this->load_grade_item();
if (!empty($this->grade_item)) {
return $this->grade_item->locked;
} else {
return false;
}
}
/**
* Sets the grade_item's locked variable and updates the grade_item.
* Method named after grade_item::set_locked().
* @param int $locked 0, 1 or a timestamp int(10) after which date the item will be locked.
* @return void
*/
function set_locked($locked) {
$this->load_grade_item();
if (!empty($this->grade_item)) {
$this->grade_item->locked = $locked;
return $this->grade_item->update();
} else {
return false;
}
}
/**
* Returns the hidden state/date of the associated grade_item. This method is also available in
* grade_item, for cases where the object type is not known.
* @return int 0, 1 or timestamp int(10)
*/
function get_hidden() {
$this->load_grade_item();
if (!empty($this->grade_item)) {
return $this->grade_item->hidden;
} else {
return false;
}
}
/**
* Sets the grade_item's hidden variable and updates the grade_item.
* Method named after grade_item::set_hidden().
* @param int $hidden 0, 1 or a timestamp int(10) after which date the item will be hidden.
* @return void
*/
function set_hidden($hidden) {
$this->load_grade_item();
if (!empty($this->grade_item)) {
$this->grade_item->hidden = $hidden;
return $this->grade_item->update();
} else {
return false;
}
}
/**
* If the old parent is set (after an update), this checks and returns whether it has any children. Important for
* deleting childless categories.
* @return boolean
*/
function is_old_parent_childless() {
if (!empty($this->old_parent)) {
return !$this->old_parent->has_children();
} else {
return false;
}
}
}
?>