cohort/lib.php

   1 <?php
   2 // This file is part of Moodle - http://moodle.org/
   3 //
   4 // Moodle is free software: you can redistribute it and/or modify
   5 // it under the terms of the GNU General Public License as published by
   6 // the Free Software Foundation, either version 3 of the License, or
   7 // (at your option) any later version.
   8 //
   9 // Moodle is distributed in the hope that it will be useful,
  10 // but WITHOUT ANY WARRANTY; without even the implied warranty of
  11 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12 // GNU General Public License for more details.
  13 //
  14 // You should have received a copy of the GNU General Public License
  15 // along with Moodle.  If not, see <http://www.gnu.org/licenses/>.
  16
  17 /**
  18  * Cohort related management functions, this file needs to be included manually.
  19  *
  20  * @package    core_cohort
  21  * @copyright  2010 Petr Skoda  {@link http://skodak.org}
  22  * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  23  */
  24
  25 defined('MOODLE_INTERNAL') || die();
  26
  27 /**
  28  * Add new cohort.
  29  *
  30  * @param  stdClass $cohort
  31  * @return int new cohort id
  32  */
  33 function cohort_add_cohort($cohort) {
  34     global $DB;
  35
  36     if (!isset($cohort->name)) {
  37         throw new coding_exception('Missing cohort name in cohort_add_cohort().');
  38     }
  39     if (!isset($cohort->idnumber)) {
  40         $cohort->idnumber = NULL;
  41     }
  42     if (!isset($cohort->description)) {
  43         $cohort->description = '';
  44     }
  45     if (!isset($cohort->descriptionformat)) {
  46         $cohort->descriptionformat = FORMAT_HTML;
  47     }
  48     if (empty($cohort->component)) {
  49         $cohort->component = '';
  50     }
  51     if (!isset($cohort->timecreated)) {
  52         $cohort->timecreated = time();
  53     }
  54     if (!isset($cohort->timemodified)) {
  55         $cohort->timemodified = $cohort->timecreated;
  56     }
  57
  58     $cohort->id = $DB->insert_record('cohort', $cohort);
  59
  60     events_trigger('cohort_added', $cohort);
  61
  62     return $cohort->id;
  63 }
  64
  65 /**
  66  * Update existing cohort.
  67  * @param  stdClass $cohort
  68  * @return void
  69  */
  70 function cohort_update_cohort($cohort) {
  71     global $DB;
  72     if (property_exists($cohort, 'component') and empty($cohort->component)) {
  73         // prevent NULLs
  74         $cohort->component = '';
  75     }
  76     $cohort->timemodified = time();
  77     $DB->update_record('cohort', $cohort);
  78
  79     events_trigger('cohort_updated', $cohort);
  80 }
  81
  82 /**
  83  * Delete cohort.
  84  * @param  stdClass $cohort
  85  * @return void
  86  */
  87 function cohort_delete_cohort($cohort) {
  88     global $DB;
  89
  90     if ($cohort->component) {
  91         // TODO: add component delete callback
  92     }
  93
  94     $DB->delete_records('cohort_members', array('cohortid'=>$cohort->id));
  95     $DB->delete_records('cohort', array('id'=>$cohort->id));
  96
  97     events_trigger('cohort_deleted', $cohort);
  98 }
  99
 100 /**
 101  * Somehow deal with cohorts when deleting course category,
 102  * we can not just delete them because they might be used in enrol
 103  * plugins or referenced in external systems.
 104  * @param  stdClass|coursecat $category
 105  * @return void
 106  */
 107 function cohort_delete_category($category) {
 108     global $DB;
 109     // TODO: make sure that cohorts are really, really not used anywhere and delete, for now just move to parent or system context
 110
 111     $oldcontext = context_coursecat::instance($category->id);
 112
 113     if ($category->parent and $parent = $DB->get_record('course_categories', array('id'=>$category->parent))) {
 114         $parentcontext = context_coursecat::instance($parent->id);
 115         $sql = "UPDATE {cohort} SET contextid = :newcontext WHERE contextid = :oldcontext";
 116         $params = array('oldcontext'=>$oldcontext->id, 'newcontext'=>$parentcontext->id);
 117     } else {
 118         $syscontext = context_system::instance();
 119         $sql = "UPDATE {cohort} SET contextid = :newcontext WHERE contextid = :oldcontext";
 120         $params = array('oldcontext'=>$oldcontext->id, 'newcontext'=>$syscontext->id);
 121     }
 122
 123     $DB->execute($sql, $params);
 124 }
 125
 126 /**
 127  * Add cohort member
 128  * @param  int $cohortid
 129  * @param  int $userid
 130  * @return void
 131  */
 132 function cohort_add_member($cohortid, $userid) {
 133     global $DB;
 134     if ($DB->record_exists('cohort_members', array('cohortid'=>$cohortid, 'userid'=>$userid))) {
 135         // No duplicates!
 136         return;
 137     }
 138     $record = new stdClass();
 139     $record->cohortid  = $cohortid;
 140     $record->userid    = $userid;
 141     $record->timeadded = time();
 142     $DB->insert_record('cohort_members', $record);
 143
 144     events_trigger('cohort_member_added', (object)array('cohortid'=>$cohortid, 'userid'=>$userid));
 145 }
 146
 147 /**
 148  * Remove cohort member
 149  * @param  int $cohortid
 150  * @param  int $userid
 151  * @return void
 152  */
 153 function cohort_remove_member($cohortid, $userid) {
 154     global $DB;
 155     $DB->delete_records('cohort_members', array('cohortid'=>$cohortid, 'userid'=>$userid));
 156
 157     events_trigger('cohort_member_removed', (object)array('cohortid'=>$cohortid, 'userid'=>$userid));
 158 }
 159
 160 /**
 161  * Is this user a cohort member?
 162  * @param int $cohortid
 163  * @param int $userid
 164  * @return bool
 165  */
 166 function cohort_is_member($cohortid, $userid) {
 167     global $DB;
 168
 169     return $DB->record_exists('cohort_members', array('cohortid'=>$cohortid, 'userid'=>$userid));
 170 }
 171
 172 /**
 173  * Returns list of cohorts from course parent contexts.
 174  *
 175  * Note: this function does not implement any capability checks,
 176  *       it means it may disclose existence of cohorts,
 177  *       make sure it is displayed to users with appropriate rights only.
 178  *
 179  * @param  stdClass $course
 180  * @param  bool $onlyenrolled true means include only cohorts with enrolled users
 181  * @return array of cohort names with number of enrolled users
 182  */
 183 function cohort_get_visible_list($course, $onlyenrolled=true) {
 184     global $DB;
 185
 186     $context = context_course::instance($course->id);
 187     list($esql, $params) = get_enrolled_sql($context);
 188     list($parentsql, $params2) = $DB->get_in_or_equal($context->get_parent_context_ids(), SQL_PARAMS_NAMED);
 189     $params = array_merge($params, $params2);
 190
 191     if ($onlyenrolled) {
 192         $left = "";
 193         $having = "HAVING COUNT(u.id) > 0";
 194     } else {
 195         $left = "LEFT";
 196         $having = "";
 197     }
 198
 199     $sql = "SELECT c.id, c.name, c.contextid, c.idnumber, COUNT(u.id) AS cnt
 200               FROM {cohort} c
 201         $left JOIN ({cohort_members} cm
 202                    JOIN ($esql) u ON u.id = cm.userid) ON cm.cohortid = c.id
 203              WHERE c.contextid $parentsql
 204           GROUP BY c.id, c.name, c.contextid, c.idnumber
 205            $having
 206           ORDER BY c.name, c.idnumber";
 207
 208     $cohorts = $DB->get_records_sql($sql, $params);
 209
 210     foreach ($cohorts as $cid=>$cohort) {
 211         $cohorts[$cid] = format_string($cohort->name, true, array('context'=>$cohort->contextid));
 212         if ($cohort->cnt) {
 213             $cohorts[$cid] .= ' (' . $cohort->cnt . ')';
 214         }
 215     }
 216
 217     return $cohorts;
 218 }
 219
 220 /**
 221  * Get all the cohorts defined in given context.
 222  *
 223  * @param int $contextid
 224  * @param int $page number of the current page
 225  * @param int $perpage items per page
 226  * @param string $search search string
 227  * @return array    Array(totalcohorts => int, cohorts => array, allcohorts => int)
 228  */
 229 function cohort_get_cohorts($contextid, $page = 0, $perpage = 25, $search = '') {
 230     global $DB;
 231
 232     // Add some additional sensible conditions
 233     $tests = array('contextid = ?');
 234     $params = array($contextid);
 235
 236     if (!empty($search)) {
 237         $conditions = array('name', 'idnumber', 'description');
 238         $searchparam = '%' . $DB->sql_like_escape($search) . '%';
 239         foreach ($conditions as $key=>$condition) {
 240             $conditions[$key] = $DB->sql_like($condition, "?", false);
 241             $params[] = $searchparam;
 242         }
 243         $tests[] = '(' . implode(' OR ', $conditions) . ')';
 244     }
 245     $wherecondition = implode(' AND ', $tests);
 246
 247     $fields = "SELECT *";
 248     $countfields = "SELECT COUNT(1)";
 249     $sql = " FROM {cohort}
 250              WHERE $wherecondition";
 251     $order = " ORDER BY name ASC, idnumber ASC";
 252     $allcohorts = $DB->count_records('cohort', array('contextid'=>$contextid));
 253     $totalcohorts = $DB->count_records_sql($countfields . $sql, $params);
 254     $cohorts = $DB->get_records_sql($fields . $sql . $order, $params, $page*$perpage, $perpage);
 255
 256     return array('totalcohorts' => $totalcohorts, 'cohorts' => $cohorts, 'allcohorts'=>$allcohorts);
 257 }