moodle/lib/grade/grade_tree.php

238 lines
8.7 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 $CFG->libdir . '/gradelib.php';
/**
* This class represents a complete tree of categories, grade_items and final grades,
* organises as an array primarily, but which can also be converted to other formats.
* It has simple method calls with complex implementations, allowing for easy insertion,
* deletion and moving of items and categories within the tree.
*/
class grade_tree {
/**
* The basic representation of the tree as a hierarchical, 3-tiered array.
* @var object $top_element
*/
var $top_element;
/**
* A string of GET URL variables, namely courseid and sesskey, used in most URLs built by this class.
* @var string $commonvars
*/
var $commonvars;
/**
* 2D array of grade items and categories
*/
var $levels;
/**
* Constructor, retrieves and stores a hierarchical array of all grade_category and grade_item
* objects for the given courseid. Full objects are instantiated.
* and renumbering.
* @param int $courseid
* @param boolean $fillers include fillers and colspans, make the levels var "rectangular"
* @param boolean $category_grade_last category grade item is the last child
* @param boolean $aggregation_view Either full view (0) or compact view (1)
*/
function grade_tree($courseid, $fillers=true, $category_grade_last=false,
$aggregation_view=GRADE_REPORT_AGGREGATION_VIEW_FULL) {
global $USER;
$this->courseid = $courseid;
$this->commonvars = "&amp;sesskey=$USER->sesskey&amp;id=$this->courseid";
$this->levels = array();
// get course grade tree
$this->top_element = grade_category::fetch_course_tree($courseid, true);
if ($category_grade_last) {
grade_tree::category_grade_last($this->top_element);
}
if ($fillers) {
// inject fake categories == fillers
grade_tree::inject_fillers($this->top_element, 0);
// add colspans to categories and fillers
grade_tree::inject_colspans($this->top_element);
}
grade_tree::fill_levels($this->levels, $this->top_element, 0);
}
/**
* Static recursive helper - makes the grade_item for category the last children
* @static
* @param array $element The seed of the recursion
* @return void
*/
function category_grade_last(&$element) {
if (empty($element['children'])) {
return;
}
if (count($element['children']) < 2) {
return;
}
$category_item = reset($element['children']);
$order = key($element['children']);
unset($element['children'][$order]);
$element['children'][$order] =& $category_item;
foreach ($element['children'] as $sortorder=>$child) {
grade_tree::category_grade_last($element['children'][$sortorder]);
}
}
/**
* Static recursive helper - fills the levels array, useful when accessing tree elements of one level
* @static
* @param int $levels
* @param array $element The seed of the recursion
* @param int $depth
* @return void
*/
function fill_levels(&$levels, &$element, $depth) {
if (!array_key_exists($depth, $levels)) {
$levels[$depth] = array();
}
// prepare unique identifier
if ($element['type'] == 'category') {
$element['eid'] = 'c'.$element['object']->id;
} else if (in_array($element['type'], array('item', 'courseitem', 'categoryitem'))) {
$element['eid'] = 'i'.$element['object']->id;
}
$levels[$depth][] =& $element;
$depth++;
if (empty($element['children'])) {
return;
}
$prev = 0;
foreach ($element['children'] as $sortorder=>$child) {
grade_tree::fill_levels($levels, $element['children'][$sortorder], $depth);
$element['children'][$sortorder]['prev'] = $prev;
$element['children'][$sortorder]['next'] = 0;
if ($prev) {
$element['children'][$prev]['next'] = $sortorder;
}
$prev = $sortorder;
}
}
/**
* Static recursive helper - makes full tree (all leafes are at the same level)
*/
function inject_fillers(&$element, $depth) {
$depth++;
if (empty($element['children'])) {
return $depth;
}
$chdepths = array();
$chids = array_keys($element['children']);
$last_child = end($chids);
$first_child = reset($chids);
foreach ($chids as $chid) {
$chdepths[$chid] = grade_tree::inject_fillers($element['children'][$chid], $depth);
}
arsort($chdepths);
$maxdepth = reset($chdepths);
foreach ($chdepths as $chid=>$chd) {
if ($chd == $maxdepth) {
continue;
}
for ($i=0; $i < $maxdepth-$chd; $i++) {
if ($chid == $first_child) {
$type = 'fillerfirst';
} else if ($chid == $last_child) {
$type = 'fillerlast';
} else {
$type = 'filler';
}
$oldchild =& $element['children'][$chid];
$element['children'][$chid] = array('object'=>'filler', 'type'=>$type, 'eid'=>'', 'depth'=>$element['object']->depth,'children'=>array($oldchild));
}
}
return $maxdepth;
}
/**
* Static recursive helper - add colspan information into categories
*/
function inject_colspans(&$element) {
if (empty($element['children'])) {
return 1;
}
$count = 0;
foreach ($element['children'] as $key=>$child) {
$count += grade_tree::inject_colspans($element['children'][$key]);
}
$element['colspan'] = $count;
return $count;
}
/**
* Parses the array in search of a given eid and returns a element object with
* information about the element it has found.
* @param int $eid
* @return object element
*/
function locate_element($eid) {
if (strpos($eid, 'g') === 0) {
// it is a grade construct a new object
$id = (int)substr($eid, 1);
if (!$grade = grade_grade::fetch(array('id'=>$id))) {
return null;
}
//extra security check - the grade item must be in this tree
if (!$item_el = $this->locate_element('i'.$grade->itemid)) {
return null;
}
$grade->grade_item =& $item_el['object']; // this may speedup grade_grade methods!
return array('eid'=>'g'.$id,'object'=>$grade, 'type'=>'grade');
}
// it is a category or item
foreach ($this->levels as $row) {
foreach ($row as $element) {
if ($element['type'] == 'filler') {
continue;
}
if ($element['eid'] == $eid) {
return $element;
}
}
}
return null;
}
}