cohort/lib.php

   1 <?php
   2
   3 // This file is part of Moodle - http://moodle.org/
   4 //
   5 // Moodle is free software: you can redistribute it and/or modify
   6 // it under the terms of the GNU General Public License as published by
   7 // the Free Software Foundation, either version 3 of the License, or
   8 // (at your option) any later version.
   9 //
  10 // Moodle is distributed in the hope that it will be useful,
  11 // but WITHOUT ANY WARRANTY; without even the implied warranty of
  12 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13 // GNU General Public License for more details.
  14 //
  15 // You should have received a copy of the GNU General Public License
  16 // along with Moodle.  If not, see <http://www.gnu.org/licenses/>.
  17
  18 /**
  19  * Cohort related management functions, this file needs to be included manually.
  20  *
  21  * @package    core
  22  * @subpackage cohort
  23  * @copyright  2010 Petr Skoda  {@link http://skodak.org}
  24  * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  25  */
  26
  27 require_once($CFG->dirroot . '/user/selector/lib.php');
  28
  29 /**
  30  * Add new cohort.
  31  *
  32  * @param  object $cohort
  33  * @return int
  34  */
  35 function cohort_add_cohort($cohort) {
  36     global $DB;
  37
  38     if (!isset($cohort->name)) {
  39         throw new coding_exception('Missing cohort name in cohort_add_cohort().');
  40     }
  41     if (!isset($cohort->idnumber)) {
  42         $cohort->idnumber = NULL;
  43     }
  44     if (!isset($cohort->description)) {
  45         $cohort->description = $DB->sql_empty();
  46     }
  47     if (!isset($cohort->descriptionformat)) {
  48         $cohort->descriptionformat = FORMAT_HTML;
  49     }
  50     if (empty($cohort->component)) {
  51         $cohort->component = '';
  52     }
  53     if (!isset($cohort->timecreated)) {
  54         $cohort->timecreated = time();
  55     }
  56     if (!isset($cohort->timemodified)) {
  57         $cohort->timemodified = $cohort->timecreated;
  58     }
  59
  60     $cohort->id = $DB->insert_record('cohort', $cohort);
  61
  62     events_trigger('cohort_added', $cohort);
  63
  64     return $cohort->id;
  65 }
  66
  67 /**
  68  * Update existing cohort.
  69  * @param  object $cohort
  70  * @return void
  71  */
  72 function cohort_update_cohort($cohort) {
  73     global $DB;
  74     if (isset($cohort->component) and empty($cohort->component)) {
  75         $cohort->component = NULL;
  76     }
  77     $cohort->timemodified = time();
  78     $DB->update_record('cohort', $cohort);
  79
  80     events_trigger('cohort_updated', $cohort);
  81 }
  82
  83 /**
  84  * Delete cohort.
  85  * @param  object $cohort
  86  * @return void
  87  */
  88 function cohort_delete_cohort($cohort) {
  89     global $DB;
  90
  91     if ($cohort->component) {
  92         // TODO: add component delete callback
  93     }
  94
  95     $DB->delete_records('cohort_members', array('cohortid'=>$cohort->id));
  96     $DB->delete_records('cohort', array('id'=>$cohort->id));
  97
  98     events_trigger('cohort_deleted', $cohort);
  99 }
 100
 101 /**
 102  * Somehow deal with cohorts when deleting course category,
 103  * we can not just delete them because they might be used in enrol
 104  * plugins or referenced in external systems.
 105  * @param  object $category
 106  * @return void
 107  */
 108 function cohort_delete_category($category) {
 109     global $DB;
 110     // TODO: make sure that cohorts are really, really not used anywhere and delete, for now just move to parent or system context
 111
 112     $oldcontext = get_context_instance(CONTEXT_COURSECAT, $category->id, MUST_EXIST);
 113
 114     if ($category->parent and $parent = $DB->get_record('course_categories', array('id'=>$category->parent))) {
 115         $parentcontext = get_context_instance(CONTEXT_COURSECAT, $parent->id, MUST_EXIST);
 116         $sql = "UPDATE {cohort} SET contextid = :newcontext WHERE contextid = :oldcontext";
 117         $params = array('oldcontext'=>$oldcontext->id, 'newcontext'=>$parentcontext->id);
 118     } else {
 119         $syscontext = get_context_instance(CONTEXT_SYSTEM);
 120         $sql = "UPDATE {cohort} SET contextid = :newcontext WHERE contextid = :oldcontext";
 121         $params = array('oldcontext'=>$oldcontext->id, 'newcontext'=>$syscontext->id);
 122     }
 123
 124     $DB->execute($sql, $params);
 125 }
 126
 127 /**
 128  * Remove cohort member
 129  * @param  int $cohortid
 130  * @param  int $userid
 131  * @return void
 132  */
 133 function cohort_add_member($cohortid, $userid) {
 134     global $DB;
 135     $record = new stdClass();
 136     $record->cohortid  = $cohortid;
 137     $record->userid    = $userid;
 138     $record->timeadded = time();
 139     $DB->insert_record('cohort_members', $record);
 140
 141     events_trigger('cohort_member_added', (object)array('cohortid'=>$cohortid, 'userid'=>$userid));
 142 }
 143
 144 /**
 145  * Add cohort member
 146  * @param  int $cohortid
 147  * @param  int $userid
 148  * @return void
 149  */
 150 function cohort_remove_member($cohortid, $userid) {
 151     global $DB;
 152     $DB->delete_records('cohort_members', array('cohortid'=>$cohortid, 'userid'=>$userid));
 153
 154     events_trigger('cohort_member_removed', (object)array('cohortid'=>$cohortid, 'userid'=>$userid));
 155 }
 156
 157 /**
 158  * Returns list of visible cohorts in course.
 159  *
 160  * @param  object $course
 161  * @param  bool $enrolled true means include only cohorts with enrolled users
 162  * @return array
 163  */
 164 function cohort_get_visible_list($course) {
 165     global $DB, $USER;
 166
 167     $context = get_context_instance(CONTEXT_COURSE, $course->id, MUST_EXIST);
 168     list($esql, $params) = get_enrolled_sql($context);
 169     $parentsql = get_related_contexts_string($context);
 170
 171     $sql = "SELECT c.id, c.name, c.idnumber, COUNT(u.id) AS cnt
 172               FROM {cohort} c
 173               JOIN {cohort_members} cm ON cm.cohortid = c.id
 174               JOIN ($esql) u ON u.id = cm.userid
 175              WHERE c.contextid $parentsql
 176           GROUP BY c.id, c.name, c.idnumber
 177             HAVING COUNT(u.id) > 0
 178           ORDER BY c.name, c.idnumber";
 179     $params['ctx'] = $context->id;
 180
 181     $cohorts = $DB->get_records_sql($sql, $params);
 182
 183     foreach ($cohorts as $cid=>$cohort) {
 184         $cohorts[$cid] = format_string($cohort->name);
 185         if ($cohort->idnumber) {
 186             $cohorts[$cid] .= ' (' . $cohort->cnt . ')';
 187         }
 188     }
 189
 190     return $cohorts;
 191 }
 192
 193 /**
 194  * Cohort assignment candidates
 195  */
 196 class cohort_candidate_selector extends user_selector_base {
 197     protected $cohortid;
 198
 199     public function __construct($name, $options) {
 200         $this->cohortid = $options['cohortid'];
 201         parent::__construct($name, $options);
 202     }
 203
 204     /**
 205      * Candidate users
 206      * @param <type> $search
 207      * @return array
 208      */
 209     public function find_users($search) {
 210         global $DB;
 211         //by default wherecondition retrieves all users except the deleted, not confirmed and guest
 212         list($wherecondition, $params) = $this->search_sql($search, 'u');
 213         $params['cohortid'] = $this->cohortid;
 214
 215         $fields      = 'SELECT ' . $this->required_fields_sql('u');
 216         $countfields = 'SELECT COUNT(1)';
 217
 218         $sql = " FROM {user} u
 219             LEFT JOIN {cohort_members} cm ON (cm.userid = u.id AND cm.cohortid = :cohortid)
 220                 WHERE cm.id IS NULL AND $wherecondition";
 221
 222         $order = ' ORDER BY u.lastname ASC, u.firstname ASC';
 223
 224         if (!$this->is_validating()) {
 225             $potentialmemberscount = $DB->count_records_sql($countfields . $sql, $params);
 226             if ($potentialmemberscount > 100) {
 227                 return $this->too_many_results($search, $potentialmemberscount);
 228             }
 229         }
 230
 231         $availableusers = $DB->get_records_sql($fields . $sql . $order, $params);
 232
 233         if (empty($availableusers)) {
 234             return array();
 235         }
 236
 237
 238         if ($search) {
 239             $groupname = get_string('potusersmatching', 'cohort', $search);
 240         } else {
 241             $groupname = get_string('potusers', 'cohort');
 242         }
 243
 244         return array($groupname => $availableusers);
 245     }
 246
 247     protected function get_options() {
 248         $options = parent::get_options();
 249         $options['cohortid'] = $this->cohortid;
 250         $options['file'] = 'cohort/lib.php';
 251         return $options;
 252     }
 253 }
 254
 255 /**
 256  * Cohort assignment candidates
 257  */
 258 class cohort_existing_selector extends user_selector_base {
 259     protected $cohortid;
 260
 261     public function __construct($name, $options) {
 262         $this->cohortid = $options['cohortid'];
 263         parent::__construct($name, $options);
 264     }
 265
 266     /**
 267      * Candidate users
 268      * @param <type> $search
 269      * @return array
 270      */
 271     public function find_users($search) {
 272         global $DB;
 273         //by default wherecondition retrieves all users except the deleted, not confirmed and guest
 274         list($wherecondition, $params) = $this->search_sql($search, 'u');
 275         $params['cohortid'] = $this->cohortid;
 276
 277         $fields      = 'SELECT ' . $this->required_fields_sql('u');
 278         $countfields = 'SELECT COUNT(1)';
 279
 280         $sql = " FROM {user} u
 281                  JOIN {cohort_members} cm ON (cm.userid = u.id AND cm.cohortid = :cohortid)
 282                 WHERE $wherecondition";
 283
 284         $order = ' ORDER BY u.lastname ASC, u.firstname ASC';
 285
 286         if (!$this->is_validating()) {
 287             $potentialmemberscount = $DB->count_records_sql($countfields . $sql, $params);
 288             if ($potentialmemberscount > 100) {
 289                 return $this->too_many_results($search, $potentialmemberscount);
 290             }
 291         }
 292
 293         $availableusers = $DB->get_records_sql($fields . $sql . $order, $params);
 294
 295         if (empty($availableusers)) {
 296             return array();
 297         }
 298
 299
 300         if ($search) {
 301             $groupname = get_string('currentusersmatching', 'cohort', $search);
 302         } else {
 303             $groupname = get_string('currentusers', 'cohort');
 304         }
 305
 306         return array($groupname => $availableusers);
 307     }
 308
 309     protected function get_options() {
 310         $options = parent::get_options();
 311         $options['cohortid'] = $this->cohortid;
 312         $options['file'] = 'cohort/lib.php';
 313         return $options;
 314     }
 315 }