weekly release 3.1dev
[moodle.git] / cohort / lib.php
CommitLineData
b980c56e 1<?php
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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 *
607fdf63 20 * @package core_cohort
707f4136 21 * @copyright 2010 Petr Skoda {@link http://skodak.org}
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22 * @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
23 */
24
607fdf63 25defined('MOODLE_INTERNAL') || die();
b980c56e 26
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27define('COHORT_ALL', 0);
28define('COHORT_COUNT_MEMBERS', 1);
29define('COHORT_COUNT_ENROLLED_MEMBERS', 3);
30define('COHORT_WITH_MEMBERS_ONLY', 5);
31define('COHORT_WITH_ENROLLED_MEMBERS_ONLY', 17);
32define('COHORT_WITH_NOTENROLLED_MEMBERS_ONLY', 23);
33
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34/**
35 * Add new cohort.
df997f84 36 *
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37 * @param stdClass $cohort
38 * @return int new cohort id
b980c56e 39 */
df997f84 40function cohort_add_cohort($cohort) {
b980c56e 41 global $DB;
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42
43 if (!isset($cohort->name)) {
13f66945 44 throw new coding_exception('Missing cohort name in cohort_add_cohort().');
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45 }
46 if (!isset($cohort->idnumber)) {
47 $cohort->idnumber = NULL;
48 }
49 if (!isset($cohort->description)) {
88a119bb 50 $cohort->description = '';
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51 }
52 if (!isset($cohort->descriptionformat)) {
53 $cohort->descriptionformat = FORMAT_HTML;
54 }
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55 if (!isset($cohort->visible)) {
56 $cohort->visible = 1;
57 }
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58 if (empty($cohort->component)) {
59 $cohort->component = '';
60 }
61 if (!isset($cohort->timecreated)) {
62 $cohort->timecreated = time();
63 }
64 if (!isset($cohort->timemodified)) {
65 $cohort->timemodified = $cohort->timecreated;
66 }
67
68 $cohort->id = $DB->insert_record('cohort', $cohort);
69
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70 $event = \core\event\cohort_created::create(array(
71 'context' => context::instance_by_id($cohort->contextid),
72 'objectid' => $cohort->id,
73 ));
74 $event->add_record_snapshot('cohort', $cohort);
75 $event->trigger();
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76
77 return $cohort->id;
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78}
79
80/**
81 * Update existing cohort.
6eb8bf7f 82 * @param stdClass $cohort
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83 * @return void
84 */
df997f84 85function cohort_update_cohort($cohort) {
b980c56e 86 global $DB;
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87 if (property_exists($cohort, 'component') and empty($cohort->component)) {
88 // prevent NULLs
89 $cohort->component = '';
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90 }
91 $cohort->timemodified = time();
92 $DB->update_record('cohort', $cohort);
93
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94 $event = \core\event\cohort_updated::create(array(
95 'context' => context::instance_by_id($cohort->contextid),
96 'objectid' => $cohort->id,
97 ));
98 $event->trigger();
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99}
100
101/**
102 * Delete cohort.
6eb8bf7f 103 * @param stdClass $cohort
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104 * @return void
105 */
106function cohort_delete_cohort($cohort) {
107 global $DB;
108
109 if ($cohort->component) {
110 // TODO: add component delete callback
111 }
112
113 $DB->delete_records('cohort_members', array('cohortid'=>$cohort->id));
114 $DB->delete_records('cohort', array('id'=>$cohort->id));
df997f84 115
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116 $event = \core\event\cohort_deleted::create(array(
117 'context' => context::instance_by_id($cohort->contextid),
118 'objectid' => $cohort->id,
119 ));
120 $event->add_record_snapshot('cohort', $cohort);
121 $event->trigger();
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122}
123
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124/**
125 * Somehow deal with cohorts when deleting course category,
126 * we can not just delete them because they might be used in enrol
127 * plugins or referenced in external systems.
b33389d2 128 * @param stdClass|coursecat $category
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129 * @return void
130 */
131function cohort_delete_category($category) {
132 global $DB;
133 // TODO: make sure that cohorts are really, really not used anywhere and delete, for now just move to parent or system context
134
abdf2b67 135 $oldcontext = context_coursecat::instance($category->id);
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136
137 if ($category->parent and $parent = $DB->get_record('course_categories', array('id'=>$category->parent))) {
abdf2b67 138 $parentcontext = context_coursecat::instance($parent->id);
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139 $sql = "UPDATE {cohort} SET contextid = :newcontext WHERE contextid = :oldcontext";
140 $params = array('oldcontext'=>$oldcontext->id, 'newcontext'=>$parentcontext->id);
141 } else {
6ca657a7 142 $syscontext = context_system::instance();
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143 $sql = "UPDATE {cohort} SET contextid = :newcontext WHERE contextid = :oldcontext";
144 $params = array('oldcontext'=>$oldcontext->id, 'newcontext'=>$syscontext->id);
145 }
146
147 $DB->execute($sql, $params);
148}
149
b980c56e 150/**
e0db105b 151 * Add cohort member
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152 * @param int $cohortid
153 * @param int $userid
154 * @return void
155 */
156function cohort_add_member($cohortid, $userid) {
157 global $DB;
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158 if ($DB->record_exists('cohort_members', array('cohortid'=>$cohortid, 'userid'=>$userid))) {
159 // No duplicates!
160 return;
161 }
fbaea88f 162 $record = new stdClass();
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163 $record->cohortid = $cohortid;
164 $record->userid = $userid;
165 $record->timeadded = time();
166 $DB->insert_record('cohort_members', $record);
df997f84 167
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168 $cohort = $DB->get_record('cohort', array('id' => $cohortid), '*', MUST_EXIST);
169
170 $event = \core\event\cohort_member_added::create(array(
171 'context' => context::instance_by_id($cohort->contextid),
172 'objectid' => $cohortid,
173 'relateduserid' => $userid,
174 ));
175 $event->add_record_snapshot('cohort', $cohort);
176 $event->trigger();
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177}
178
179/**
e0db105b 180 * Remove cohort member
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181 * @param int $cohortid
182 * @param int $userid
183 * @return void
184 */
185function cohort_remove_member($cohortid, $userid) {
186 global $DB;
187 $DB->delete_records('cohort_members', array('cohortid'=>$cohortid, 'userid'=>$userid));
df997f84 188
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189 $cohort = $DB->get_record('cohort', array('id' => $cohortid), '*', MUST_EXIST);
190
191 $event = \core\event\cohort_member_removed::create(array(
192 'context' => context::instance_by_id($cohort->contextid),
193 'objectid' => $cohortid,
194 'relateduserid' => $userid,
195 ));
196 $event->add_record_snapshot('cohort', $cohort);
197 $event->trigger();
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198}
199
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200/**
201 * Is this user a cohort member?
202 * @param int $cohortid
203 * @param int $userid
204 * @return bool
205 */
206function cohort_is_member($cohortid, $userid) {
207 global $DB;
208
209 return $DB->record_exists('cohort_members', array('cohortid'=>$cohortid, 'userid'=>$userid));
210}
211
92343cd2 212/**
80f98467 213 * Returns the list of cohorts visible to the current user in the given course.
92343cd2 214 *
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215 * The following fields are returned in each record: id, name, contextid, idnumber, visible
216 * Fields memberscnt and enrolledcnt will be also returned if requested
a09ae434 217 *
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218 * @param context $currentcontext
219 * @param int $withmembers one of the COHORT_XXX constants that allows to return non empty cohorts only
220 * or cohorts with enroled/not enroled users, or just return members count
221 * @param int $offset
222 * @param int $limit
223 * @param string $search
224 * @return array
92343cd2 225 */
80f98467 226function cohort_get_available_cohorts($currentcontext, $withmembers = 0, $offset = 0, $limit = 25, $search = '') {
a09ae434 227 global $DB;
92343cd2 228
80f98467 229 $params = array();
a09ae434 230
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231 // Build context subquery. Find the list of parent context where user is able to see any or visible-only cohorts.
232 // Since this method is normally called for the current course all parent contexts are already preloaded.
233 $contextsany = array_filter($currentcontext->get_parent_context_ids(),
234 create_function('$a', 'return has_capability("moodle/cohort:view", context::instance_by_id($a));'));
235 $contextsvisible = array_diff($currentcontext->get_parent_context_ids(), $contextsany);
236 if (empty($contextsany) && empty($contextsvisible)) {
237 // User does not have any permissions to view cohorts.
238 return array();
239 }
240 $subqueries = array();
241 if (!empty($contextsany)) {
242 list($parentsql, $params1) = $DB->get_in_or_equal($contextsany, SQL_PARAMS_NAMED, 'ctxa');
243 $subqueries[] = 'c.contextid ' . $parentsql;
244 $params = array_merge($params, $params1);
245 }
246 if (!empty($contextsvisible)) {
247 list($parentsql, $params1) = $DB->get_in_or_equal($contextsvisible, SQL_PARAMS_NAMED, 'ctxv');
248 $subqueries[] = '(c.visible = 1 AND c.contextid ' . $parentsql. ')';
249 $params = array_merge($params, $params1);
250 }
251 $wheresql = '(' . implode(' OR ', $subqueries) . ')';
252
253 // Build the rest of the query.
254 $fromsql = "";
255 $fieldssql = 'c.id, c.name, c.contextid, c.idnumber, c.visible';
256 $groupbysql = '';
257 $havingsql = '';
258 if ($withmembers) {
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259 $fieldssql .= ', s.memberscnt';
260 $subfields = "c.id, COUNT(DISTINCT cm.userid) AS memberscnt";
261 $groupbysql = " GROUP BY c.id";
80f98467 262 $fromsql = " LEFT JOIN {cohort_members} cm ON cm.cohortid = c.id ";
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263 if (in_array($withmembers,
264 array(COHORT_COUNT_ENROLLED_MEMBERS, COHORT_WITH_ENROLLED_MEMBERS_ONLY, COHORT_WITH_NOTENROLLED_MEMBERS_ONLY))) {
265 list($esql, $params2) = get_enrolled_sql($currentcontext);
266 $fromsql .= " LEFT JOIN ($esql) u ON u.id = cm.userid ";
267 $params = array_merge($params2, $params);
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268 $fieldssql .= ', s.enrolledcnt';
269 $subfields .= ', COUNT(DISTINCT u.id) AS enrolledcnt';
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270 }
271 if ($withmembers == COHORT_WITH_MEMBERS_ONLY) {
272 $havingsql = " HAVING COUNT(DISTINCT cm.userid) > 0";
273 } else if ($withmembers == COHORT_WITH_ENROLLED_MEMBERS_ONLY) {
274 $havingsql = " HAVING COUNT(DISTINCT u.id) > 0";
275 } else if ($withmembers == COHORT_WITH_NOTENROLLED_MEMBERS_ONLY) {
276 $havingsql = " HAVING COUNT(DISTINCT cm.userid) > COUNT(DISTINCT u.id)";
277 }
278 }
279 if ($search) {
280 list($searchsql, $searchparams) = cohort_get_search_query($search);
281 $wheresql .= ' AND ' . $searchsql;
282 $params = array_merge($params, $searchparams);
a09ae434 283 }
92343cd2 284
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285 if ($withmembers) {
286 $sql = "SELECT " . str_replace('c.', 'cohort.', $fieldssql) . "
287 FROM {cohort} cohort
288 JOIN (SELECT $subfields
289 FROM {cohort} c $fromsql
290 WHERE $wheresql $groupbysql $havingsql
291 ) s ON cohort.id = s.id
292 ORDER BY cohort.name, cohort.idnumber";
293 } else {
294 $sql = "SELECT $fieldssql
295 FROM {cohort} c $fromsql
296 WHERE $wheresql
297 ORDER BY c.name, c.idnumber";
298 }
92343cd2 299
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300 return $DB->get_records_sql($sql, $params, $offset, $limit);
301}
302
303/**
304 * Check if cohort exists and user is allowed to access it from the given context.
305 *
306 * @param stdClass|int $cohortorid cohort object or id
307 * @param context $currentcontext current context (course) where visibility is checked
308 * @return boolean
309 */
310function cohort_can_view_cohort($cohortorid, $currentcontext) {
311 global $DB;
312 if (is_numeric($cohortorid)) {
313 $cohort = $DB->get_record('cohort', array('id' => $cohortorid), 'id, contextid, visible');
314 } else {
315 $cohort = $cohortorid;
316 }
92343cd2 317
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318 if ($cohort && in_array($cohort->contextid, $currentcontext->get_parent_context_ids())) {
319 if ($cohort->visible) {
320 return true;
321 }
322 $cohortcontext = context::instance_by_id($cohort->contextid);
323 if (has_capability('moodle/cohort:view', $cohortcontext)) {
324 return true;
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325 }
326 }
80f98467 327 return false;
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328}
329
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330/**
331 * Produces a part of SQL query to filter cohorts by the search string
332 *
80f98467 333 * Called from {@link cohort_get_cohorts()}, {@link cohort_get_all_cohorts()} and {@link cohort_get_available_cohorts()}
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334 *
335 * @access private
336 *
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337 * @param string $search search string
338 * @param string $tablealias alias of cohort table in the SQL query (highly recommended if other tables are used in query)
339 * @return array of two elements - SQL condition and array of named parameters
274dc068 340 */
80f98467 341function cohort_get_search_query($search, $tablealias = '') {
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342 global $DB;
343 $params = array();
344 if (empty($search)) {
345 // This function should not be called if there is no search string, just in case return dummy query.
346 return array('1=1', $params);
347 }
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348 if ($tablealias && substr($tablealias, -1) !== '.') {
349 $tablealias .= '.';
350 }
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351 $searchparam = '%' . $DB->sql_like_escape($search) . '%';
352 $conditions = array();
353 $fields = array('name', 'idnumber', 'description');
80f98467 354 $cnt = 0;
274dc068 355 foreach ($fields as $field) {
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356 $conditions[] = $DB->sql_like($tablealias . $field, ':csearch' . $cnt, false);
357 $params['csearch' . $cnt] = $searchparam;
358 $cnt++;
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359 }
360 $sql = '(' . implode(' OR ', $conditions) . ')';
361 return array($sql, $params);
362}
363
543009cb 364/**
aad6e655 365 * Get all the cohorts defined in given context.
543009cb 366 *
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367 * The function does not check user capability to view/manage cohorts in the given context
368 * assuming that it has been already verified.
369 *
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370 * @param int $contextid
371 * @param int $page number of the current page
372 * @param int $perpage items per page
373 * @param string $search search string
9a2f6770 374 * @return array Array(totalcohorts => int, cohorts => array, allcohorts => int)
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375 */
376function cohort_get_cohorts($contextid, $page = 0, $perpage = 25, $search = '') {
377 global $DB;
378
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379 $fields = "SELECT *";
380 $countfields = "SELECT COUNT(1)";
381 $sql = " FROM {cohort}
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382 WHERE contextid = :contextid";
383 $params = array('contextid' => $contextid);
274dc068 384 $order = " ORDER BY name ASC, idnumber ASC";
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385
386 if (!empty($search)) {
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387 list($searchcondition, $searchparams) = cohort_get_search_query($search);
388 $sql .= ' AND ' . $searchcondition;
389 $params = array_merge($params, $searchparams);
543009cb 390 }
543009cb 391
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392 $totalcohorts = $allcohorts = $DB->count_records('cohort', array('contextid' => $contextid));
393 if (!empty($search)) {
394 $totalcohorts = $DB->count_records_sql($countfields . $sql, $params);
395 }
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396 $cohorts = $DB->get_records_sql($fields . $sql . $order, $params, $page*$perpage, $perpage);
397
274dc068 398 return array('totalcohorts' => $totalcohorts, 'cohorts' => $cohorts, 'allcohorts' => $allcohorts);
543009cb 399}
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400
401/**
402 * Get all the cohorts defined anywhere in system.
403 *
404 * The function assumes that user capability to view/manage cohorts on system level
405 * has already been verified. This function only checks if such capabilities have been
406 * revoked in child (categories) contexts.
407 *
408 * @param int $page number of the current page
409 * @param int $perpage items per page
410 * @param string $search search string
411 * @return array Array(totalcohorts => int, cohorts => array, allcohorts => int)
412 */
413function cohort_get_all_cohorts($page = 0, $perpage = 25, $search = '') {
414 global $DB;
415
416 $fields = "SELECT c.*, ".context_helper::get_preload_record_columns_sql('ctx');
417 $countfields = "SELECT COUNT(*)";
418 $sql = " FROM {cohort} c
419 JOIN {context} ctx ON ctx.id = c.contextid ";
420 $params = array();
421 $wheresql = '';
422
423 if ($excludedcontexts = cohort_get_invisible_contexts()) {
80f98467 424 list($excludedsql, $excludedparams) = $DB->get_in_or_equal($excludedcontexts, SQL_PARAMS_NAMED, 'excl', false);
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425 $wheresql = ' WHERE c.contextid '.$excludedsql;
426 $params = array_merge($params, $excludedparams);
427 }
428
429 $totalcohorts = $allcohorts = $DB->count_records_sql($countfields . $sql . $wheresql, $params);
430
431 if (!empty($search)) {
80f98467 432 list($searchcondition, $searchparams) = cohort_get_search_query($search, 'c');
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433 $wheresql .= ($wheresql ? ' AND ' : ' WHERE ') . $searchcondition;
434 $params = array_merge($params, $searchparams);
435 $totalcohorts = $DB->count_records_sql($countfields . $sql . $wheresql, $params);
436 }
437
438 $order = " ORDER BY c.name ASC, c.idnumber ASC";
439 $cohorts = $DB->get_records_sql($fields . $sql . $wheresql . $order, $params, $page*$perpage, $perpage);
440
441 // Preload used contexts, they will be used to check view/manage/assign capabilities and display categories names.
442 foreach (array_keys($cohorts) as $key) {
443 context_helper::preload_from_record($cohorts[$key]);
444 }
445
446 return array('totalcohorts' => $totalcohorts, 'cohorts' => $cohorts, 'allcohorts' => $allcohorts);
447}
448
449/**
450 * Returns list of contexts where cohorts are present but current user does not have capability to view/manage them.
451 *
452 * This function is called from {@link cohort_get_all_cohorts()} to ensure correct pagination in rare cases when user
453 * is revoked capability in child contexts. It assumes that user's capability to view/manage cohorts on system
454 * level has already been verified.
455 *
456 * @access private
457 *
458 * @return array array of context ids
459 */
460function cohort_get_invisible_contexts() {
461 global $DB;
462 if (is_siteadmin()) {
463 // Shortcut, admin can do anything and can not be prohibited from any context.
464 return array();
465 }
466 $records = $DB->get_recordset_sql("SELECT DISTINCT ctx.id, ".context_helper::get_preload_record_columns_sql('ctx')." ".
467 "FROM {context} ctx JOIN {cohort} c ON ctx.id = c.contextid ");
468 $excludedcontexts = array();
469 foreach ($records as $ctx) {
470 context_helper::preload_from_record($ctx);
471 if (!has_any_capability(array('moodle/cohort:manage', 'moodle/cohort:view'), context::instance_by_id($ctx->id))) {
472 $excludedcontexts[] = $ctx->id;
473 }
474 }
475 return $excludedcontexts;
476}
477
478/**
479 * Returns navigation controls (tabtree) to be displayed on cohort management pages
480 *
481 * @param context $context system or category context where cohorts controls are about to be displayed
482 * @param moodle_url $currenturl
483 * @return null|renderable
484 */
485function cohort_edit_controls(context $context, moodle_url $currenturl) {
486 $tabs = array();
487 $currenttab = 'view';
488 $viewurl = new moodle_url('/cohort/index.php', array('contextid' => $context->id));
489 if (($searchquery = $currenturl->get_param('search'))) {
490 $viewurl->param('search', $searchquery);
491 }
492 if ($context->contextlevel == CONTEXT_SYSTEM) {
493 $tabs[] = new tabobject('view', new moodle_url($viewurl, array('showall' => 0)), get_string('systemcohorts', 'cohort'));
494 $tabs[] = new tabobject('viewall', new moodle_url($viewurl, array('showall' => 1)), get_string('allcohorts', 'cohort'));
495 if ($currenturl->get_param('showall')) {
496 $currenttab = 'viewall';
497 }
498 } else {
499 $tabs[] = new tabobject('view', $viewurl, get_string('cohorts', 'cohort'));
500 }
501 if (has_capability('moodle/cohort:manage', $context)) {
502 $addurl = new moodle_url('/cohort/edit.php', array('contextid' => $context->id));
503 $tabs[] = new tabobject('addcohort', $addurl, get_string('addcohort', 'cohort'));
504 if ($currenturl->get_path() === $addurl->get_path() && !$currenturl->param('id')) {
505 $currenttab = 'addcohort';
506 }
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507
508 $uploadurl = new moodle_url('/cohort/upload.php', array('contextid' => $context->id));
509 $tabs[] = new tabobject('uploadcohorts', $uploadurl, get_string('uploadcohorts', 'cohort'));
510 if ($currenturl->get_path() === $uploadurl->get_path()) {
511 $currenttab = 'uploadcohorts';
512 }
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513 }
514 if (count($tabs) > 1) {
515 return new tabtree($tabs, $currenttab);
516 }
517 return null;
80f98467 518}