Fix a possible race condition in the PaintWeb DML code.
[moodle/mihaisucan.git] / group / autogroup.php
blobadd9d3561f031886758c19726c2fd283d8acee7b
1 <?php // $Id$
2 /**
3 * Create and allocate users go groups
5 * @author Matt Clarkson mattc@catalyst.net.nz
6 * @version 0.0.1
7 * @license http://www.gnu.org/copyleft/gpl.html GNU Public License
8 * @package groups
9 */
11 require_once('../config.php');
12 require_once('lib.php');
13 require_once('autogroup_form.php');
15 if (!defined('AUTOGROUP_MIN_RATIO')) {
16 define('AUTOGROUP_MIN_RATIO', 0.7); // means minimum member count is 70% in the smallest group
19 $courseid = required_param('courseid', PARAM_INT);
21 if (!$course = get_record('course', 'id', $courseid)) {
22 error('invalidcourse');
25 // Make sure that the user has permissions to manage groups.
26 require_login($course);
28 $context = get_context_instance(CONTEXT_COURSE, $courseid);
29 $systemcontext = get_context_instance(CONTEXT_SYSTEM);
30 require_capability('moodle/course:managegroups', $context);
32 $returnurl = $CFG->wwwroot.'/group/index.php?id='.$course->id;
34 $strgroups = get_string('groups');
35 $strparticipants = get_string('participants');
36 $strautocreategroups = get_string('autocreategroups', 'group');
38 // Print the page and form
39 $navlinks = array(array('name'=>$strparticipants, 'link'=>$CFG->wwwroot.'/user/index.php?id='.$courseid, 'type'=>'misc'),
40 array('name' => $strgroups, 'link' => "$CFG->wwwroot/group/index.php?id=$courseid", 'type' => 'misc'),
41 array('name' => $strautocreategroups, 'link' => null, 'type' => 'misc'));
42 $navigation = build_navigation($navlinks);
44 $preview = '';
45 $error = '';
47 /// Get applicable roles
48 $rolenames = array();
49 if ($roles = get_roles_used_in_context($context, true)) {
50 $canviewroles = get_roles_with_capability('moodle/course:view', CAP_ALLOW, $context);
51 $doanythingroles = get_roles_with_capability('moodle/site:doanything', CAP_ALLOW, $systemcontext);
53 foreach ($roles as $role) {
54 if (!isset($canviewroles[$role->id])) { // Avoid this role (eg course creator)
55 continue;
57 if (isset($doanythingroles[$role->id])) { // Avoid this role (ie admin)
58 continue;
60 $rolenames[$role->id] = strip_tags(role_get_name($role, $context)); // Used in menus etc later on
64 /// Create the form
65 $editform = new autogroup_form(null, array('roles' => $rolenames));
66 $editform->set_data(array('courseid' => $courseid, 'seed' => time()));
68 /// Handle form submission
69 if ($editform->is_cancelled()) {
70 redirect($returnurl);
72 } elseif ($data = $editform->get_data(false)) {
74 /// Allocate members from the selected role to groups
75 switch ($data->allocateby) {
76 case 'no':
77 case 'random':
78 case 'lastname':
79 $orderby = 'lastname, firstname'; break;
80 case 'firstname':
81 $orderby = 'firstname, lastname'; break;
82 case 'idnumber':
83 $orderby = 'idnumber'; break;
84 default:
85 error('Unknown ordering');
87 $users = groups_get_potential_members($data->courseid, $data->roleid, $orderby);
88 $usercnt = count($users);
90 if ($data->allocateby == 'random') {
91 srand($data->seed);
92 shuffle($users);
95 $groups = array();
97 // Plan the allocation
98 if ($data->groupby == 'groups') {
99 $numgrps = $data->number;
100 $userpergrp = floor($usercnt/$numgrps);
102 } else { // members
103 $numgrps = ceil($usercnt/$data->number);
104 $userpergrp = $data->number;
106 if (!empty($data->nosmallgroups) and $usercnt % $data->number != 0) {
107 // If there would be one group with a small number of member reduce the number of groups
108 $missing = $userpergrp * $numgrps - $usercnt;
109 if ($missing > $userpergrp * (1-AUTOGROUP_MIN_RATIO)) {
110 // spread the users from the last small group
111 $numgrps--;
112 $userpergrp = floor($usercnt/$numgrps);
117 // allocate the users - all groups equal count first
118 for ($i=0; $i<$numgrps; $i++) {
119 $groups[$i] = array();
120 $groups[$i]['name'] = groups_parse_name(trim($data->namingscheme), $i);
121 $groups[$i]['members'] = array();
122 if ($data->allocateby == 'no') {
123 continue; // do not allocate users
125 for ($j=0; $j<$userpergrp; $j++) {
126 if (empty($users)) {
127 break 2;
129 $user = array_shift($users);
130 $groups[$i]['members'][$user->id] = $user;
133 // now distribute the rest
134 if ($data->allocateby != 'no') {
135 for ($i=0; $i<$numgrps; $i++) {
136 if (empty($users)) {
137 break 1;
139 $user = array_shift($users);
140 $groups[$i]['members'][$user->id] = $user;
144 if (isset($data->preview)) {
145 $table = new object();
146 if ($data->allocateby == 'no') {
147 $table->head = array(get_string('groupscount', 'group', $numgrps));
148 $table->size = array('100%');
149 $table->align = array('left');
150 $table->width = '40%';
151 } else {
152 $table->head = array(get_string('groupscount', 'group', $numgrps), get_string('groupmembers', 'group'), get_string('usercounttotal', 'group', $usercnt));
153 $table->size = array('20%', '70%', '10%');
154 $table->align = array('left', 'left', 'center');
155 $table->width = '90%';
157 $table->data = array();
159 foreach ($groups as $group) {
160 $line = array();
161 if (groups_get_group_by_name($courseid, $group['name'])) {
162 $line[] = '<span class="notifyproblem">'.get_string('groupnameexists', 'group', $group['name']).'</span>';
163 $error = get_string('groupnameexists', 'group', $group['name']);
164 } else {
165 $line[] = $group['name'];
167 if ($data->allocateby != 'no') {
168 $unames = array();
169 foreach ($group['members'] as $user) {
170 $unames[] = fullname($user, true);
172 $line[] = implode(', ', $unames);
173 $line[] = count($group['members']);
175 $table->data[] = $line;
178 $preview .= print_table($table, true);
180 } else {
181 $grouping = null;
182 $createdgrouping = null;
183 $createdgroups = array();
184 $failed = false;
186 // prepare grouping
187 if (!empty($data->grouping)) {
188 $groupingname = trim($data->groupingname);
189 if ($data->grouping < 0) {
190 $grouping = new object();
191 $grouping->courseid = $COURSE->id;
192 $grouping->name = $groupingname;
193 if (!$grouping->id = groups_create_grouping(addslashes_recursive($grouping))) {
194 $error = 'Can not create grouping'; //should not happen
195 $failed = true;
197 $createdgrouping = $grouping->id;
198 } else {
199 $grouping = groups_get_grouping($data->grouping);
203 // Save the groups data
204 foreach ($groups as $key=>$group) {
205 if (groups_get_group_by_name($courseid, $group['name'])) {
206 $error = get_string('groupnameexists', 'group', $group['name']);
207 $failed = true;
208 break;
210 $newgroup = new object();
211 $newgroup->courseid = $data->courseid;
212 $newgroup->name = $group['name'];
213 if (!$groupid = groups_create_group(addslashes_recursive($newgroup))) {
214 $error = 'Can not create group!'; // should not happen
215 $failed = true;
216 break;
218 $createdgroups[] = $groupid;
219 foreach($group['members'] as $user) {
220 groups_add_member($groupid, $user->id);
222 if ($grouping) {
223 groups_assign_grouping($grouping->id, $groupid);
227 if ($failed) {
228 foreach ($createdgroups as $groupid) {
229 groups_delete_group($groupid);
231 if ($createdgrouping) {
232 groups_delete_grouping($createdgrouping);
234 } else {
235 redirect($returnurl);
240 /// Print header
241 print_header_simple($strgroups, ': '.$strgroups, $navigation, '', '', true, '', navmenu($course));
242 print_heading($strautocreategroups);
244 if ($error != '') {
245 notify($error);
248 /// Display the form
249 $editform->display();
251 if($preview !== '') {
252 print_heading(get_string('groupspreview', 'group'));
254 echo $preview;
257 print_footer($course);