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 $DB;
  74     if (property_exists($cohort, 'component') and empty($cohort->component)) {
  75         // prevent NULLs
  76         $cohort->component = '';
  77     }
  78     $cohort->timemodified = time();
  79     $DB->update_record('cohort', $cohort);
  80
  81     events_trigger('cohort_updated', $cohort);
  82 }
  83
  84 /**
  85  * Delete cohort.
  86  * @param  object $cohort
  87  * @return void
  88  */
  89 function cohort_delete_cohort($cohort) {
  90     global $DB;
  91
  92     if ($cohort->component) {
  93         // TODO: add component delete callback
  94     }
  95
  96     $DB->delete_records('cohort_members', array('cohortid'=>$cohort->id));
  97     $DB->delete_records('cohort', array('id'=>$cohort->id));
  98
  99     events_trigger('cohort_deleted', $cohort);
 100 }
 101
 102 /**
 103  * Somehow deal with cohorts when deleting course category,
 104  * we can not just delete them because they might be used in enrol
 105  * plugins or referenced in external systems.
 106  * @param  object $category
 107  * @return void
 108  */
 109 function cohort_delete_category($category) {
 110     global $DB;
 111     // TODO: make sure that cohorts are really, really not used anywhere and delete, for now just move to parent or system context
 112
 113     $oldcontext = get_context_instance(CONTEXT_COURSECAT, $category->id, MUST_EXIST);
 114
 115     if ($category->parent and $parent = $DB->get_record('course_categories', array('id'=>$category->parent))) {
 116         $parentcontext = get_context_instance(CONTEXT_COURSECAT, $parent->id, MUST_EXIST);
 117         $sql = "UPDATE {cohort} SET contextid = :newcontext WHERE contextid = :oldcontext";
 118         $params = array('oldcontext'=>$oldcontext->id, 'newcontext'=>$parentcontext->id);
 119     } else {
 120         $syscontext = get_context_instance(CONTEXT_SYSTEM);
 121         $sql = "UPDATE {cohort} SET contextid = :newcontext WHERE contextid = :oldcontext";
 122         $params = array('oldcontext'=>$oldcontext->id, 'newcontext'=>$syscontext->id);
 123     }
 124
 125     $DB->execute($sql, $params);
 126 }
 127
 128 /**
 129  * Remove cohort member
 130  * @param  int $cohortid
 131  * @param  int $userid
 132  * @return void
 133  */
 134 function cohort_add_member($cohortid, $userid) {
 135     global $DB;
 136     $record = new stdClass();
 137     $record->cohortid  = $cohortid;
 138     $record->userid    = $userid;
 139     $record->timeadded = time();
 140     $DB->insert_record('cohort_members', $record);
 141
 142     events_trigger('cohort_member_added', (object)array('cohortid'=>$cohortid, 'userid'=>$userid));
 143 }
 144
 145 /**
 146  * Add cohort member
 147  * @param  int $cohortid
 148  * @param  int $userid
 149  * @return void
 150  */
 151 function cohort_remove_member($cohortid, $userid) {
 152     global $DB;
 153     $DB->delete_records('cohort_members', array('cohortid'=>$cohortid, 'userid'=>$userid));
 154
 155     events_trigger('cohort_member_removed', (object)array('cohortid'=>$cohortid, 'userid'=>$userid));
 156 }
 157
 158 /**
 159  * Returns list of visible cohorts in course.
 160  *
 161  * @param  object $course
 162  * @param  bool $enrolled true means include only cohorts with enrolled users
 163  * @return array
 164  */
 165 function cohort_get_visible_list($course) {
 166     global $DB, $USER;
 167
 168     $context = get_context_instance(CONTEXT_COURSE, $course->id, MUST_EXIST);
 169     list($esql, $params) = get_enrolled_sql($context);
 170     $parentsql = get_related_contexts_string($context);
 171
 172     $sql = "SELECT c.id, c.name, c.idnumber, COUNT(u.id) AS cnt
 173               FROM {cohort} c
 174               JOIN {cohort_members} cm ON cm.cohortid = c.id
 175               JOIN ($esql) u ON u.id = cm.userid
 176              WHERE c.contextid $parentsql
 177           GROUP BY c.id, c.name, c.idnumber
 178             HAVING COUNT(u.id) > 0
 179           ORDER BY c.name, c.idnumber";
 180     $params['ctx'] = $context->id;
 181
 182     $cohorts = $DB->get_records_sql($sql, $params);
 183
 184     foreach ($cohorts as $cid=>$cohort) {
 185         $cohorts[$cid] = format_string($cohort->name);
 186         if ($cohort->idnumber) {
 187             $cohorts[$cid] .= ' (' . $cohort->cnt . ')';
 188         }
 189     }
 190
 191     return $cohorts;
 192 }
 193
 194 /**
 195  * Get all the cohorts.
 196  *
 197  * @global moodle_database $DB
 198  * @param int $contextid
 199  * @param int $page number of the current page
 200  * @param int $perpage items per page
 201  * @param string $search search string
 202  * @return array    Array(totalcohorts => int, cohorts => array)
 203  */
 204 function cohort_get_cohorts($contextid, $page = 0, $perpage = 25, $search = '') {
 205     global $DB;
 206
 207     $cohorts = array();
 208
 209     // Add some additional sensible conditions
 210     $tests = array('contextid = ?');
 211     $params = array($contextid);
 212
 213     if (!empty($search)) {
 214         $conditions = array(
 215             'name',
 216             'idnumber',
 217             'description',
 218         );
 219         $searchparam = '%' . $search . '%';
 220         foreach ($conditions as $key=>$condition) {
 221             $conditions[$key] = $DB->sql_like($condition,"?", false);
 222             $params[] = $searchparam;
 223         }
 224         $tests[] = '(' . implode(' OR ', $conditions) . ')';
 225     }
 226     $wherecondition = implode(' AND ', $tests);
 227
 228     $fields = 'SELECT *';
 229     $countfields = 'SELECT COUNT(1)';
 230     $sql = " FROM {cohort}
 231              WHERE $wherecondition";
 232     $order = ' ORDER BY name ASC';
 233     $totalcohorts = $DB->count_records_sql($countfields . $sql, $params);
 234     $cohorts = $DB->get_records_sql($fields . $sql . $order, $params, $page*$perpage, $perpage);
 235
 236     return array('totalcohorts' => $totalcohorts, 'cohorts' => $cohorts);
 237 }
 238
 239 /**
 240  * Cohort assignment candidates
 241  */
 242 class cohort_candidate_selector extends user_selector_base {
 243     protected $cohortid;
 244
 245     public function __construct($name, $options) {
 246         $this->cohortid = $options['cohortid'];
 247         parent::__construct($name, $options);
 248     }
 249
 250     /**
 251      * Candidate users
 252      * @param <type> $search
 253      * @return array
 254      */
 255     public function find_users($search) {
 256         global $DB;
 257         //by default wherecondition retrieves all users except the deleted, not confirmed and guest
 258         list($wherecondition, $params) = $this->search_sql($search, 'u');
 259         $params['cohortid'] = $this->cohortid;
 260
 261         $fields      = 'SELECT ' . $this->required_fields_sql('u');
 262         $countfields = 'SELECT COUNT(1)';
 263
 264         $sql = " FROM {user} u
 265             LEFT JOIN {cohort_members} cm ON (cm.userid = u.id AND cm.cohortid = :cohortid)
 266                 WHERE cm.id IS NULL AND $wherecondition";
 267
 268         $order = ' ORDER BY u.lastname ASC, u.firstname ASC';
 269
 270         if (!$this->is_validating()) {
 271             $potentialmemberscount = $DB->count_records_sql($countfields . $sql, $params);
 272             if ($potentialmemberscount > 100) {
 273                 return $this->too_many_results($search, $potentialmemberscount);
 274             }
 275         }
 276
 277         $availableusers = $DB->get_records_sql($fields . $sql . $order, $params);
 278
 279         if (empty($availableusers)) {
 280             return array();
 281         }
 282
 283
 284         if ($search) {
 285             $groupname = get_string('potusersmatching', 'cohort', $search);
 286         } else {
 287             $groupname = get_string('potusers', 'cohort');
 288         }
 289
 290         return array($groupname => $availableusers);
 291     }
 292
 293     protected function get_options() {
 294         $options = parent::get_options();
 295         $options['cohortid'] = $this->cohortid;
 296         $options['file'] = 'cohort/lib.php';
 297         return $options;
 298     }
 299 }
 300
 301 /**
 302  * Cohort assignment candidates
 303  */
 304 class cohort_existing_selector extends user_selector_base {
 305     protected $cohortid;
 306
 307     public function __construct($name, $options) {
 308         $this->cohortid = $options['cohortid'];
 309         parent::__construct($name, $options);
 310     }
 311
 312     /**
 313      * Candidate users
 314      * @param <type> $search
 315      * @return array
 316      */
 317     public function find_users($search) {
 318         global $DB;
 319         //by default wherecondition retrieves all users except the deleted, not confirmed and guest
 320         list($wherecondition, $params) = $this->search_sql($search, 'u');
 321         $params['cohortid'] = $this->cohortid;
 322
 323         $fields      = 'SELECT ' . $this->required_fields_sql('u');
 324         $countfields = 'SELECT COUNT(1)';
 325
 326         $sql = " FROM {user} u
 327                  JOIN {cohort_members} cm ON (cm.userid = u.id AND cm.cohortid = :cohortid)
 328                 WHERE $wherecondition";
 329
 330         $order = ' ORDER BY u.lastname ASC, u.firstname ASC';
 331
 332         if (!$this->is_validating()) {
 333             $potentialmemberscount = $DB->count_records_sql($countfields . $sql, $params);
 334             if ($potentialmemberscount > 100) {
 335                 return $this->too_many_results($search, $potentialmemberscount);
 336             }
 337         }
 338
 339         $availableusers = $DB->get_records_sql($fields . $sql . $order, $params);
 340
 341         if (empty($availableusers)) {
 342             return array();
 343         }
 344
 345
 346         if ($search) {
 347             $groupname = get_string('currentusersmatching', 'cohort', $search);
 348         } else {
 349             $groupname = get_string('currentusers', 'cohort');
 350         }
 351
 352         return array($groupname => $availableusers);
 353     }
 354
 355     protected function get_options() {
 356         $options = parent::get_options();
 357         $options['cohortid'] = $this->cohortid;
 358         $options['file'] = 'cohort/lib.php';
 359         return $options;
 360     }
 361 }