MDL-40908 core_tag: created a 'tag_unflagged' event
[moodle.git] / tag / lib.php
CommitLineData
6bfe7aac 1<?php
000ebd5c
DM
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
bcdcee90 17
c933a060 18/**
4a0daed7 19 * Moodle tag library
db32b054 20 *
bcdcee90
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21 * Tag strings : you can use any character in tags, except the comma (which is the separator) and
22 * the '\' (backslash). Note that many spaces (or other blank characters) will get "compressed"
23 * into one. A tag string is always a rawurlencode'd string. This is the same behavior as
24 * http://del.icio.us.
d4be9d6d 25 *
bcdcee90
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26 * A "record" is a php array (note that an object will work too) that contains the following
27 * variables :
28 * - type: The database table containing the record that we are tagging (eg: for a blog, this is
29 * the table named 'post', and for a user it is the table name 'user')
30 * - id: The id of the record
c933a060 31 *
986dca60 32 * BASIC INSTRUCTIONS :
33 * - to "tag a blog post" (for example):
cc033d48 34 * tag_set('post', $blog_post->id, $array_of_tags, 'core', $thecontext);
d4be9d6d 35 *
db32b054 36 * - to "remove all the tags on a blog post":
cc033d48 37 * tag_set('post', $blog_post->id, array(), 'core', $thecontext);
4a0daed7 38 *
39 * Tag set will create tags that need to be created.
d4be9d6d 40 *
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41 * @package core_tag
42 * @category tag
43 * @todo MDL-31090 turn this into a full-fledged categorization system. This could start by
44 * modifying (removing, probably) the 'tag type' to use another table describing the
45 * relationship between tags (parents, sibling, etc.), which could then be merged with
46 * the 'course categorization' system.
47 * @see http://www.php.net/manual/en/function.urlencode.php
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48 * @copyright 2007 Luiz Cruz <luiz.laydner@gmail.com>
49 * @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
c933a060 50 */
51
bcdcee90
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52/**
53 * Used to require that the return value from a function is an array.
54 * @see tag_set()
55 */
db32b054 56define('TAG_RETURN_ARRAY', 0);
bcdcee90
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57/**
58 * Used to require that the return value from a function is an object.
59 * @see tag_set()
60 */
db32b054 61define('TAG_RETURN_OBJECT', 1);
bcdcee90
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62/**
63 * Use to specify that HTML free text is expected to be returned from a function.
64 * @see tag_display_name()
65 */
db32b054 66define('TAG_RETURN_TEXT', 2);
bcdcee90
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67/**
68 * Use to specify that encoded HTML is expected to be returned from a function.
69 * @see tag_display_name()
70 */
db32b054 71define('TAG_RETURN_HTML', 3);
c933a060 72
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73/**
74 * Used to specify that we wish a lowercased string to be returned
75 * @see tag_normal()
76 */
db32b054 77define('TAG_CASE_LOWER', 0);
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78/**
79 * Used to specify that we do not wish the case of the returned string to change
80 * @see tag_normal()
81 */
db32b054 82define('TAG_CASE_ORIGINAL', 1);
d4be9d6d 83
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84/**
85 * Used to specify that we want all related tags returned, no matter how they are related.
86 * @see tag_get_related_tags()
87 */
537aa65c 88define('TAG_RELATED_ALL', 0);
bcdcee90
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89/**
90 * Used to specify that we only want back tags that were manually related.
91 * @see tag_get_related_tags()
92 */
537aa65c 93define('TAG_RELATED_MANUAL', 1);
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94/**
95 * Used to specify that we only want back tags where the relationship was automatically correlated.
96 * @see tag_get_related_tags()
97 */
537aa65c 98define('TAG_RELATED_CORRELATED', 2);
99
db32b054 100///////////////////////////////////////////////////////
101/////////////////// PUBLIC TAG API ////////////////////
c933a060 102
8479c2e0 103/// Functions for settings tags //////////////////////
104
c933a060 105/**
8479c2e0 106 * Set the tags assigned to a record. This overwrites the current tags.
986dca60 107 *
bcdcee90 108 * This function is meant to be fed the string coming up from the user interface, which contains all tags assigned to a record.
8479c2e0 109 *
cc033d48 110 * @package core_tag
bcdcee90 111 * @category tag
cc033d48
MN
112 * @access public
113 * @param string $record_type the type of record to tag ('post' for blogs, 'user' for users, 'tag' for tags, etc.)
114 * @param int $record_id the id of the record to tag
115 * @param array $tags the array of tags to set on the record. If given an empty array, all tags will be removed.
116 * @param string|null $component the component that was tagged
117 * @param int|null $contextid the context id of where this tag was assigned
118 * @return bool|null
c933a060 119 */
cc033d48 120function tag_set($record_type, $record_id, $tags, $component = null, $contextid = null) {
3d436d8a 121
28f64040 122 static $in_recursion_semaphore = false; // this is to prevent loops when tagging a tag
cc033d48 123
28f64040 124 if ( $record_type == 'tag' && !$in_recursion_semaphore) {
125 $current_tagged_tag_name = tag_get_name($record_id);
126 }
8479c2e0 127
128 $tags_ids = tag_get_id($tags, TAG_RETURN_ARRAY); // force an array, even if we only have one tag.
129 $cleaned_tags = tag_normalize($tags);
130 //echo 'tags-in-tag_set'; var_dump($tags); var_dump($tags_ids); var_dump($cleaned_tags);
131
28f64040 132 $current_ids = tag_get_tags_ids($record_type, $record_id);
986dca60 133 //var_dump($current_ids);
8479c2e0 134
135 // for data coherence reasons, it's better to remove deleted tags
136 // before adding new data: ordering could be duplicated.
137 foreach($current_ids as $current_id) {
138 if (!in_array($current_id, $tags_ids)) {
28f64040 139 tag_delete_instance($record_type, $record_id, $current_id);
140 if ( $record_type == 'tag' && !$in_recursion_semaphore) {
986dca60 141 // if we are removing a tag-on-a-tag (manually related tag),
28f64040 142 // we need to remove the opposite relationship as well.
143 tag_delete_instance('tag', $current_id, $record_id);
144 }
8479c2e0 145 }
c933a060 146 }
3d436d8a 147
0f097239 148 if (empty($tags)) {
149 return true;
150 }
151
8479c2e0 152 foreach($tags as $ordering => $tag) {
153 $tag = trim($tag);
154 if (!$tag) {
db32b054 155 continue;
156 }
8479c2e0 157
158 $clean_tag = $cleaned_tags[$tag];
159 $tag_current_id = $tags_ids[$clean_tag];
986dca60 160
8479c2e0 161 if ( is_null($tag_current_id) ) {
162 // create new tags
163 //echo "call to add tag $tag\n";
164 $new_tag = tag_add($tag);
28f64040 165 $tag_current_id = $new_tag[$clean_tag];
166 }
167
cc033d48 168 tag_assign($record_type, $record_id, $tag_current_id, $ordering, 0, $component, $contextid);
28f64040 169
170 // if we are tagging a tag (adding a manually-assigned related tag), we
171 // need to create the opposite relationship as well.
172 if ( $record_type == 'tag' && !$in_recursion_semaphore) {
173 $in_recursion_semaphore = true;
cc033d48 174 tag_set_add('tag', $tag_current_id, $current_tagged_tag_name, $component, $contextid);
28f64040 175 $in_recursion_semaphore = false;
db32b054 176 }
177 }
8479c2e0 178}
3d436d8a 179
8479c2e0 180/**
181 * Adds a tag to a record, without overwriting the current tags.
986dca60 182 *
cc033d48 183 * @package core_tag
bcdcee90 184 * @category tag
cc033d48
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185 * @access public
186 * @param string $record_type the type of record to tag ('post' for blogs, 'user' for users, etc.)
187 * @param int $record_id the id of the record to tag
188 * @param string $tag the tag to add
189 * @param string|null $component the component that was tagged
190 * @param int|null $contextid the context id of where this tag was assigned
191 * @return bool|null
8479c2e0 192 */
cc033d48 193function tag_set_add($record_type, $record_id, $tag, $component = null, $contextid = null) {
8479c2e0 194
195 $new_tags = array();
b91de8a5 196 foreach( tag_get_tags($record_type, $record_id) as $current_tag ) {
8479c2e0 197 $new_tags[] = $current_tag->rawname;
198 }
199 $new_tags[] = $tag;
986dca60 200
cc033d48 201 return tag_set($record_type, $record_id, $new_tags, $component, $contextid);
c933a060 202}
203
204/**
8479c2e0 205 * Removes a tag from a record, without overwriting other current tags.
986dca60 206 *
cc033d48 207 * @package core_tag
bcdcee90 208 * @category tag
cc033d48
MN
209 * @access public
210 * @param string $record_type the type of record to tag ('post' for blogs, 'user' for users, etc.)
211 * @param int $record_id the id of the record to tag
212 * @param string $tag the tag to delete
213 * @param string|null $component the component that was tagged
214 * @param int|null $contextid the context id of where this tag was assigned
215 * @return bool|null
c933a060 216 */
cc033d48 217function tag_set_delete($record_type, $record_id, $tag, $component = null, $contextid = null) {
70e9b59d 218
8479c2e0 219 $new_tags = array();
220 foreach( tag_get_tags($record_type, $record_id) as $current_tag ) {
221 if ($current_tag->name != $tag) { // Keep all tags but the one specified
222 $new_tags[] = $current_tag->name;
db32b054 223 }
c933a060 224 }
28f64040 225
cc033d48 226 return tag_set($record_type, $record_id, $new_tags, $component, $contextid);
8479c2e0 227}
228
229/**
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230 * Set the type of a tag. At this time (version 2.2) the possible values are 'default' or 'official'. Official tags will be
231 * displayed separately "at tagging time" (while selecting the tags to apply to a record).
8479c2e0 232 *
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233 * @package core_tag
234 * @category tag
235 * @access public
236 * @param string $tagid tagid to modify
237 * @param string $type either 'default' or 'official'
238 * @return bool true on success, false otherwise
8479c2e0 239 */
240function tag_type_set($tagid, $type) {
f7ed2687 241 global $DB;
242
09fce434 243 if ($tag = $DB->get_record('tag', array('id' => $tagid), 'id, userid, name, rawname')) {
f7ed2687 244 $tag->tagtype = $type;
8479c2e0 245 $tag->timemodified = time();
09fce434
MN
246 $DB->update_record('tag', $tag);
247
248 $event = \core\event\tag_updated::create(array(
249 'objectid' => $tag->id,
250 'relateduserid' => $tag->userid,
251 'context' => context_system::instance(),
252 'other' => array(
253 'name' => $tag->name,
254 'rawname' => $tag->rawname
255 )
256 ));
257 $event->trigger();
258
259 return true;
8479c2e0 260 }
261 return false;
c933a060 262}
263
986dca60 264/**
b50d2245 265 * Set the description of a tag
986dca60 266 *
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267 * @package core_tag
268 * @category tag
269 * @access public
270 * @param int $tagid the id of the tag
271 * @param string $description the tag's description string to be set
272 * @param int $descriptionformat the moodle text format of the description
273 * {@link http://docs.moodle.org/dev/Text_formats_2.0#Database_structure}
274 * @return bool true on success, false otherwise
b50d2245 275 */
276function tag_description_set($tagid, $description, $descriptionformat) {
f7ed2687 277 global $DB;
278
09fce434 279 if ($tag = $DB->get_record('tag', array('id' => $tagid), 'id, userid, name, rawname')) {
f7ed2687 280 $tag->description = $description;
281 $tag->descriptionformat = $descriptionformat;
b50d2245 282 $tag->timemodified = time();
09fce434
MN
283 $DB->update_record('tag', $tag);
284
285 $event = \core\event\tag_updated::create(array(
286 'objectid' => $tag->id,
287 'relateduserid' => $tag->userid,
288 'context' => context_system::instance(),
289 'other' => array(
290 'name' => $tag->name,
291 'rawname' => $tag->rawname
292 )
293 ));
294 $event->trigger();
295
296 return true;
b50d2245 297 }
09fce434 298
b50d2245 299 return false;
300}
301
3d436d8a 302
6361e02a 303
db32b054 304
c933a060 305
c933a060 306
8479c2e0 307/// Functions for getting information about tags //////
2f4b82f4 308
309/**
8479c2e0 310 * Simple function to just return a single tag object when you know the name or something
2f4b82f4 311 *
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312 * @package core_tag
313 * @category tag
314 * @access public
315 * @param string $field which field do we use to identify the tag: id, name or rawname
316 * @param string $value the required value of the aforementioned field
317 * @param string $returnfields which fields do we want returned. This is a comma seperated string containing any combination of
318 * 'id', 'name', 'rawname' or '*' to include all fields.
319 * @return mixed tag object
320 */
2f4b82f4 321function tag_get($field, $value, $returnfields='id, name, rawname') {
f7ed2687 322 global $DB;
323
8479c2e0 324 if ($field == 'name') {
2f1e464a 325 $value = core_text::strtolower($value); // To cope with input that might just be wrong case
8479c2e0 326 }
f7ed2687 327 return $DB->get_record('tag', array($field=>$value), $returnfields);
2f4b82f4 328}
329
330
c933a060 331/**
bcdcee90
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332 * Get the array of db record of tags associated to a record (instances). Use {@see tag_get_tags_csv()} if you wish to get the same
333 * data in a comma-separated string, for instances such as needing to simply display a list of tags to the end user. This should
334 * really be called tag_get_tag_instances().
c933a060 335 *
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336 * @package core_tag
337 * @category tag
338 * @access public
986dca60 339 * @param string $record_type the record type for which we want to get the tags
340 * @param int $record_id the record id for which we want to get the tags
bcdcee90
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341 * @param string $type the tag type (either 'default' or 'official'). By default, all tags are returned.
342 * @param int $userid (optional) only required for course tagging
db32b054 343 * @return array the array of tags
c933a060 344 */
38fb8190 345function tag_get_tags($record_type, $record_id, $type=null, $userid=0) {
f7ed2687 346 global $CFG, $DB;
347
348 $params = array();
3d436d8a 349
db32b054 350 if ($type) {
cda19b7a 351 $sql_type = "AND tg.tagtype = :type";
f7ed2687 352 $params['type'] = $type;
353 } else {
cda19b7a 354 $sql_type = '';
db32b054 355 }
537aa65c 356
38fb8190 357 $u = null;
358 if ($userid) {
359 $u = "AND ti.tiuserid = :userid ";
360 $params['userid'] = $userid;
361 }
362
f45d62e7 363 $sql = "SELECT ti.id AS taginstanceid, tg.id, tg.tagtype, tg.name, tg.rawname, tg.flag, ti.ordering
638cf615
AD
364 FROM {tag_instance} ti
365 JOIN {tag} tg ON tg.id = ti.tagid
38fb8190 366 WHERE ti.itemtype = :recordtype AND ti.itemid = :recordid $u $sql_type
f7ed2687 367 ORDER BY ti.ordering ASC";
368 $params['recordtype'] = $record_type;
369 $params['recordid'] = $record_id;
370
73c32e86 371 // if the fields in this query are changed, you need to do the same changes in tag_get_correlated_tags
f7ed2687 372 return $DB->get_records_sql($sql, $params);
986dca60 373 // This version of the query, reversing the ON clause, "correctly" returns
374 // a row with NULL values for instances that are still in the DB even though
375 // the tag has been deleted. This shouldn't happen, but if it did, using
db32b054 376 // this query could help "clean it up". This causes bugs at this time.
f7ed2687 377 //$tags = $DB->get_records_sql("SELECT ti.tagid, tg.tagtype, tg.name, tg.rawname, tg.flag, ti.ordering ".
5183f0cc 378 // "FROM {tag_instance} ti LEFT JOIN {tag} tg ON ti.tagid = tg.id ".
537aa65c 379 // "WHERE ti.itemtype = '{$record_type}' AND ti.itemid = '{$record_id}' {$type} ".
2f9ba531 380 // "ORDER BY ti.ordering ASC");
db32b054 381}
382
383/**
384 * Get the array of tags display names, indexed by id.
986dca60 385 *
bcdcee90
GGC
386 * @package core_tag
387 * @category tag
388 * @access public
389 * @param string $record_type the record type for which we want to get the tags
390 * @param int $record_id the record id for which we want to get the tags
391 * @param string $type the tag type (either 'default' or 'official'). By default, all tags are returned.
392 * @return array the array of tags (with the value returned by tag_display_name), indexed by id
db32b054 393 */
537aa65c 394function tag_get_tags_array($record_type, $record_id, $type=null) {
db32b054 395 $tags = array();
537aa65c 396 foreach(tag_get_tags($record_type, $record_id, $type) as $tag) {
db32b054 397 $tags[$tag->id] = tag_display_name($tag);
4f81c51d 398 }
db32b054 399 return $tags;
c933a060 400}
401
402/**
bcdcee90 403 * Get a comma-separated string of tags associated to a record. Use {@see tag_get_tags()} to get the same information in an array.
c933a060 404 *
bcdcee90
GGC
405 * @package core_tag
406 * @category tag
407 * @access public
408 * @param string $record_type the record type for which we want to get the tags
409 * @param int $record_id the record id for which we want to get the tags
410 * @param int $html either TAG_RETURN_HTML or TAG_RETURN_TEXT, depending on the type of output desired
411 * @param string $type either 'official' or 'default', if null, all tags are returned
412 * @return string the comma-separated list of tags.
c933a060 413 */
537aa65c 414function tag_get_tags_csv($record_type, $record_id, $html=TAG_RETURN_HTML, $type=null) {
db32b054 415 global $CFG;
c933a060 416
417 $tags_names = array();
8479c2e0 418 foreach(tag_get_tags($record_type, $record_id, $type) as $tag) {
db32b054 419 if ($html == TAG_RETURN_TEXT) {
e7134583 420 $tags_names[] = tag_display_name($tag, TAG_RETURN_TEXT);
db32b054 421 } else { // TAG_RETURN_HTML
422 $tags_names[] = '<a href="'. $CFG->wwwroot .'/tag/index.php?tag='. rawurlencode($tag->name) .'">'. tag_display_name($tag) .'</a>';
423 }
c933a060 424 }
db32b054 425 return implode(', ', $tags_names);
c933a060 426}
427
4f81c51d 428/**
db32b054 429 * Get an array of tag ids associated to a record.
d4be9d6d 430 *
bcdcee90
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431 * @package core_tag
432 * @category tag
433 * @access public
434 * @todo MDL-31150 Update ordering property
435 * @param string $record_type the record type for which we want to get the tags
436 * @param int $record_id the record id for which we want to get the tags
437 * @return array tag ids, indexed and sorted by 'ordering'
4f81c51d 438 */
537aa65c 439function tag_get_tags_ids($record_type, $record_id) {
db32b054 440 $tag_ids = array();
8479c2e0 441 foreach (tag_get_tags($record_type, $record_id) as $tag) {
28f64040 442 if ( array_key_exists($tag->ordering, $tag_ids) ) {
443 // until we can add a unique constraint, in table tag_instance,
444 // on (itemtype, itemid, ordering), this is needed to prevent a bug
bcdcee90 445 // TODO MDL-31150 modify database in 2.0
28f64040 446 $tag->ordering++;
447 }
db32b054 448 $tag_ids[$tag->ordering] = $tag->id;
449 }
450 ksort($tag_ids);
451 return $tag_ids;
452}
3d436d8a 453
986dca60 454/**
db32b054 455 * Returns the database ID of a set of tags.
986dca60 456 *
bcdcee90
GGC
457 * @package core_tag
458 * @category tag
459 * @access public
460 * @todo MDL-31152 Test the commented MDL-31152 todo in this function to see if it helps performance
461 * without breaking anything.
462 * @param mixed $tags one tag, or array of tags, to look for.
463 * @param bool $return_value specify the type of the returned value. Either TAG_RETURN_OBJECT, or TAG_RETURN_ARRAY (default).
464 * If TAG_RETURN_ARRAY is specified, an array will be returned even if only one tag was passed in $tags.
465 * @return mixed tag-indexed array of ids (or objects, if second parameter is TAG_RETURN_OBJECT), or only an int, if only one tag
466 * is given *and* the second parameter is null. No value for a key means the tag wasn't found.
db32b054 467 */
468function tag_get_id($tags, $return_value=null) {
f7ed2687 469 global $CFG, $DB;
470
db32b054 471 static $tag_id_cache = array();
3d436d8a 472
db32b054 473 $return_an_int = false;
474 if (!is_array($tags)) {
475 if(is_null($return_value) || $return_value == TAG_RETURN_OBJECT) {
986dca60 476 $return_an_int = true;
db32b054 477 }
478 $tags = array($tags);
479 }
986dca60 480
db32b054 481 $result = array();
986dca60 482
bcdcee90 483 //TODO MDL-31152 test this and see if it helps performance without breaking anything
db32b054 484 //foreach($tags as $key => $tag) {
2f1e464a 485 // $clean_tag = core_text::strtolower($tag);
db32b054 486 // if ( array_key_exists($clean_tag), $tag_id_cache) ) {
487 // $result[$clean_tag] = $tag_id_cache[$clean_tag];
488 // $tags[$key] = ''; // prevent further processing for this one.
489 // }
490 //}
491
492 $tags = array_values(tag_normalize($tags));
493 foreach($tags as $key => $tag) {
2f1e464a
PS
494 $tags[$key] = core_text::strtolower($tag);
495 $result[core_text::strtolower($tag)] = null; // key must exists : no value for a key means the tag wasn't found.
db32b054 496 }
db32b054 497
f7ed2687 498 if (empty($tags)) {
499 return array();
500 }
501
502 list($tag_string, $params) = $DB->get_in_or_equal($tags);
503
cd5fdfd8
EL
504 $rs = $DB->get_recordset_sql("SELECT * FROM {tag} WHERE name $tag_string ORDER BY name", $params);
505 foreach ($rs as $record) {
506 if ($return_value == TAG_RETURN_OBJECT) {
507 $result[$record->name] = $record;
508 } else { // TAG_RETURN_ARRAY
509 $result[$record->name] = $record->id;
db32b054 510 }
4f81c51d 511 }
cd5fdfd8 512 $rs->close();
3d436d8a 513
db32b054 514 if ($return_an_int) {
515 return array_pop($result);
516 }
3d436d8a 517
db32b054 518 return $result;
c933a060 519}
520
c933a060 521
522/**
db32b054 523 * Returns tags related to a tag
d4be9d6d 524 *
db32b054 525 * Related tags of a tag come from two sources:
526 * - manually added related tags, which are tag_instance entries for that tag
bcdcee90 527 * - correlated tags, which are calculated
d4be9d6d 528 *
bcdcee90
GGC
529 * @package core_tag
530 * @category tag
531 * @access public
532 * @param string $tagid is a single **normalized** tag name or the id of a tag
533 * @param int $type the function will return either manually (TAG_RELATED_MANUAL) related tags or correlated
534 * (TAG_RELATED_CORRELATED) tags. Default is TAG_RELATED_ALL, which returns everything.
535 * @param int $limitnum (optional) return a subset comprising this many records, the default is 10
536 * @return array an array of tag objects
c933a060 537 */
537aa65c 538function tag_get_related_tags($tagid, $type=TAG_RELATED_ALL, $limitnum=10) {
c933a060 539
537aa65c 540 $related_tags = array();
541
542 if ( $type == TAG_RELATED_ALL || $type == TAG_RELATED_MANUAL) {
543 //gets the manually added related tags
544 $related_tags = tag_get_tags('tag', $tagid);
c933a060 545 }
546
537aa65c 547 if ( $type == TAG_RELATED_ALL || $type == TAG_RELATED_CORRELATED ) {
548 //gets the correlated tags
549 $automatic_related_tags = tag_get_correlated($tagid, $limitnum);
550 if (is_array($automatic_related_tags)) {
551 $related_tags = array_merge($related_tags, $automatic_related_tags);
552 }
db32b054 553 }
3d436d8a 554
db32b054 555 return array_slice(object_array_unique($related_tags), 0 , $limitnum);
c933a060 556}
557
986dca60 558/**
db32b054 559 * Get a comma-separated list of tags related to another tag.
d4be9d6d 560 *
bcdcee90
GGC
561 * @package core_tag
562 * @category tag
563 * @access public
564 * @param array $related_tags the array returned by tag_get_related_tags
565 * @param int $html either TAG_RETURN_HTML (default) or TAG_RETURN_TEXT : return html links, or just text.
566 * @return string comma-separated list
c933a060 567 */
db32b054 568function tag_get_related_tags_csv($related_tags, $html=TAG_RETURN_HTML) {
569 global $CFG;
c933a060 570
db32b054 571 $tags_names = array();
572 foreach($related_tags as $tag) {
573 if ( $html == TAG_RETURN_TEXT) {
e7134583 574 $tags_names[] = tag_display_name($tag, TAG_RETURN_TEXT);
db32b054 575 } else {
576 // TAG_RETURN_HTML
9fccb889 577 $tags_names[] = '<a href="'. $CFG->wwwroot .'/tag/index.php?tag='. rawurlencode($tag->name) .'">'. tag_display_name($tag) .'</a>';
c933a060 578 }
c933a060 579 }
b50d2245 580
db32b054 581 return implode(', ', $tags_names);
c933a060 582}
583
3a597ace 584/**
db32b054 585 * Change the "value" of a tag, and update the associated 'name'.
3a597ace 586 *
bcdcee90
GGC
587 * @package core_tag
588 * @category tag
589 * @access public
590 * @param int $tagid the id of the tag to modify
591 * @param string $newrawname the new rawname
592 * @return bool true on success, false otherwise
3a597ace 593 */
73c32e86 594function tag_rename($tagid, $newrawname) {
09fce434 595 global $COURSE, $DB;
3a597ace 596
7c2cc9c8
PS
597 $norm = tag_normalize($newrawname, TAG_CASE_ORIGINAL);
598 if (! $newrawname_clean = array_shift($norm) ) {
db32b054 599 return false;
600 }
3a597ace 601
2f1e464a 602 if (! $newname_clean = core_text::strtolower($newrawname_clean)) {
2f4b82f4 603 return false;
604 }
605
606 // Prevent the rename if a tag with that name already exists
607 if ($existing = tag_get('name', $newname_clean, 'id, name, rawname')) {
608 if ($existing->id != $tagid) { // Another tag already exists with this name
986dca60 609 return false;
2f4b82f4 610 }
db32b054 611 }
3a597ace 612
09fce434
MN
613 if ($tag = tag_get('id', $tagid, 'id, userid, name, rawname')) {
614 // Store the name before we change it.
615 $oldname = $tag->name;
616
617 $tag->rawname = $newrawname_clean;
618 $tag->name = $newname_clean;
db32b054 619 $tag->timemodified = time();
09fce434
MN
620 $DB->update_record('tag', $tag);
621
622 $event = \core\event\tag_updated::create(array(
623 'objectid' => $tag->id,
624 'relateduserid' => $tag->userid,
625 'context' => context_system::instance(),
626 'other' => array(
627 'name' => $newname_clean,
628 'rawname' => $newrawname_clean
629 )
630 ));
631 $event->set_legacy_logdata(array($COURSE->id, 'tag', 'update', 'index.php?id='. $tag->id, $oldname . '->'. $tag->name));
632 $event->trigger();
633
634 return true;
db32b054 635 }
636 return false;
3a597ace 637}
638
8479c2e0 639
c933a060 640/**
8479c2e0 641 * Delete one or more tag, and all their instances if there are any left.
986dca60 642 *
bcdcee90
GGC
643 * @package core_tag
644 * @category tag
645 * @access public
646 * @param mixed $tagids one tagid (int), or one array of tagids to delete
647 * @return bool true on success, false otherwise
c933a060 648 */
8479c2e0 649function tag_delete($tagids) {
f7ed2687 650 global $DB;
3d436d8a 651
8479c2e0 652 if (!is_array($tagids)) {
653 $tagids = array($tagids);
db32b054 654 }
3d436d8a 655
8479c2e0 656 $success = true;
43731030 657 $context = context_system::instance();
e2a64d83 658 foreach ($tagids as $tagid) {
8479c2e0 659 if (is_null($tagid)) { // can happen if tag doesn't exists
db32b054 660 continue;
26d8649f 661 }
986dca60 662 // only delete the main entry if there were no problems deleting all the
663 // instances - that (and the fact we won't often delete lots of tags)
8618fd2a 664 // is the reason for not using $DB->delete_records_select()
e2a64d83 665 if ($DB->delete_records('tag_instance', array('tagid'=>$tagid)) && $DB->delete_records('tag_correlation', array('tagid' => $tagid))) {
f7ed2687 666 $success &= (bool) $DB->delete_records('tag', array('id'=>$tagid));
8bdc9cac
SH
667 // Delete all files associated with this tag
668 $fs = get_file_storage();
64f93798 669 $files = $fs->get_area_files($context->id, 'tag', 'description', $tagid);
8bdc9cac
SH
670 foreach ($files as $file) {
671 $file->delete();
672 }
1acd661d 673 }
c933a060 674 }
8479c2e0 675
676 return $success;
db32b054 677}
c933a060 678
db32b054 679/**
bcdcee90 680 * Delete one instance of a tag. If the last instance was deleted, it will also delete the tag, unless its type is 'official'.
8479c2e0 681 *
bcdcee90
GGC
682 * @package core_tag
683 * @category tag
684 * @access public
685 * @param string $record_type the type of the record for which to remove the instance
686 * @param int $record_id the id of the record for which to remove the instance
687 * @param int $tagid the tagid that needs to be removed
688 * @return bool true on success, false otherwise
db32b054 689 */
28f64040 690function tag_delete_instance($record_type, $record_id, $tagid) {
f7ed2687 691 global $CFG, $DB;
692
693 if ($DB->delete_records('tag_instance', array('tagid'=>$tagid, 'itemtype'=>$record_type, 'itemid'=>$record_id))) {
a72529c7 694 if (!$DB->record_exists_sql("SELECT * ".
695 "FROM {tag} tg ".
696 "WHERE tg.id = ? AND ( tg.tagtype = 'official' OR ".
b91de8a5 697 "EXISTS (SELECT 1
698 FROM {tag_instance} ti
699 WHERE ti.tagid = ?) )",
700 array($tagid, $tagid))) {
8479c2e0 701 return tag_delete($tagid);
702 }
703 } else {
704 return false;
db32b054 705 }
4a0daed7 706
707 return true;
db32b054 708}
c933a060 709
8479c2e0 710
3627b0e3 711/**
8479c2e0 712 * Function that returns the name that should be displayed for a specific tag
713 *
bcdcee90
GGC
714 * @package core_tag
715 * @category tag
716 * @access public
717 * @param object $tagobject a line out of tag table, as returned by the adobd functions
718 * @param int $html TAG_RETURN_HTML (default) will return htmlspecialchars encoded string, TAG_RETURN_TEXT will not encode.
719 * @return string
3627b0e3 720 */
e7134583 721function tag_display_name($tagobject, $html=TAG_RETURN_HTML) {
8479c2e0 722 global $CFG;
723
34b93e39 724 if (!isset($tagobject->name)) {
8479c2e0 725 return '';
726 }
727
728 if (empty($CFG->keeptagnamecase)) {
729 //this is the normalized tag name
2f1e464a 730 $tagname = core_text::strtotitle($tagobject->name);
8479c2e0 731 } else {
732 //original casing of the tag name
e7134583 733 $tagname = $tagobject->rawname;
3627b0e3 734 }
e7134583 735
34b93e39
PS
736 // clean up a bit just in case the rules change again
737 $tagname = clean_param($tagname, PARAM_TAG);
738
e7134583 739 if ($html == TAG_RETURN_TEXT) {
740 return $tagname;
741 } else { // TAG_RETURN_HTML
742 return htmlspecialchars($tagname);
b91de8a5 743 }
3627b0e3 744}
745
db32b054 746/**
8479c2e0 747 * Find all records tagged with a tag of a given type ('post', 'user', etc.)
db32b054 748 *
bcdcee90
GGC
749 * @package core_tag
750 * @category tag
751 * @access public
752 * @param string $tag tag to look for
753 * @param string $type type to restrict search to. If null, every matching record will be returned
754 * @param int $limitfrom (optional, required if $limitnum is set) return a subset of records, starting at this point.
755 * @param int $limitnum (optional, required if $limitfrom is set) return a subset comprising this many records.
756 * @return array of matching objects, indexed by record id, from the table containing the type requested
db32b054 757 */
8479c2e0 758function tag_find_records($tag, $type, $limitfrom='', $limitnum='') {
f7ed2687 759 global $CFG, $DB;
8479c2e0 760
761 if (!$tag || !$type) {
762 return array();
db32b054 763 }
8479c2e0 764
765 $tagid = tag_get_id($tag);
766
f7ed2687 767 $query = "SELECT it.*
768 FROM {".$type."} it INNER JOIN {tag_instance} tt ON it.id = tt.itemid
769 WHERE tt.itemtype = ? AND tt.tagid = ?";
770 $params = array($type, $tagid);
986dca60 771
772 return $DB->get_records_sql($query, $params, $limitfrom, $limitnum);
c933a060 773}
774
8479c2e0 775
776
777
db32b054 778///////////////////////////////////////////////////////
779/////////////////// PRIVATE TAG API ///////////////////
c933a060 780
781/**
bcdcee90
GGC
782 * Adds one or more tag in the database. This function should not be called directly : you should
783 * use tag_set.
d4be9d6d 784 *
bcdcee90
GGC
785 * @package core_tag
786 * @access private
787 * @param mixed $tags one tag, or an array of tags, to be created
788 * @param string $type type of tag to be created ("default" is the default value and "official" is the only other supported
789 * value at this time). An official tag is kept even if there are no records tagged with it.
790 * @return array $tags ids indexed by their lowercase normalized names. Any boolean false in the array indicates an error while
791 * adding the tag.
c933a060 792 */
db32b054 793function tag_add($tags, $type="default") {
f7ed2687 794 global $USER, $DB;
c933a060 795
db32b054 796 if (!is_array($tags)) {
797 $tags = array($tags);
c933a060 798 }
3d436d8a 799
db32b054 800 $tag_object = new StdClass;
f7ed2687 801 $tag_object->tagtype = $type;
802 $tag_object->userid = $USER->id;
803 $tag_object->timemodified = time();
c933a060 804
db32b054 805 $clean_tags = tag_normalize($tags, TAG_CASE_ORIGINAL);
c933a060 806
db32b054 807 $tags_ids = array();
808 foreach($clean_tags as $tag) {
809 $tag = trim($tag);
810 if (!$tag) {
811 $tags_ids[$tag] = false;
812 } else {
986dca60 813 // note that the difference between rawname and name is only
814 // capitalization : the rawname is NOT the same at the rawtag.
815 $tag_object->rawname = $tag;
2f1e464a 816 $tag_name_lc = core_text::strtolower($tag);
f7ed2687 817 $tag_object->name = $tag_name_lc;
db32b054 818 //var_dump($tag_object);
f7ed2687 819 $tags_ids[$tag_name_lc] = $DB->insert_record('tag', $tag_object);
db32b054 820 }
821 }
c933a060 822
db32b054 823 return $tags_ids;
c933a060 824}
825
826/**
bcdcee90 827 * Assigns a tag to a record; if the record already exists, the time and ordering will be updated.
986dca60 828 *
bcdcee90 829 * @package core_tag
cc033d48
MN
830 * @access private
831 * @param string $record_type the type of the record that will be tagged
832 * @param int $record_id the id of the record that will be tagged
833 * @param string $tagid the tag id to set on the record.
834 * @param int $ordering the order of the instance for this record
835 * @param int $userid (optional) only required for course tagging
836 * @param string|null $component the component that was tagged
837 * @param int|null $contextid the context id of where this tag was assigned
838 * @return bool true on success, false otherwise
c933a060 839 */
cc033d48 840function tag_assign($record_type, $record_id, $tagid, $ordering, $userid = 0, $component = null, $contextid = null) {
f7ed2687 841 global $DB;
c933a060 842
cc033d48
MN
843 if ($component === null || $contextid === null) {
844 debugging('You should specify the component and contextid of the item being tagged in your call to tag_assign.',
845 DEBUG_DEVELOPER);
846 }
847
cfa2c6e1
MN
848 // Get the tag.
849 $tag = $DB->get_record('tag', array('id' => $tagid), 'name, rawname', MUST_EXIST);
850
38fb8190 851 if ( $tag_instance_object = $DB->get_record('tag_instance', array('tagid'=>$tagid, 'itemtype'=>$record_type, 'itemid'=>$record_id, 'tiuserid'=>$userid), 'id')) {
f7ed2687 852 $tag_instance_object->ordering = $ordering;
db32b054 853 $tag_instance_object->timemodified = time();
cfa2c6e1
MN
854
855 $DB->update_record('tag_instance', $tag_instance_object);
986dca60 856 } else {
db32b054 857 $tag_instance_object = new StdClass;
f7ed2687 858 $tag_instance_object->tagid = $tagid;
cc033d48 859 $tag_instance_object->component = $component;
f7ed2687 860 $tag_instance_object->itemid = $record_id;
861 $tag_instance_object->itemtype = $record_type;
cc033d48 862 $tag_instance_object->contextid = $contextid;
f7ed2687 863 $tag_instance_object->ordering = $ordering;
cc033d48
MN
864 $tag_instance_object->timecreated = time();
865 $tag_instance_object->timemodified = $tag_instance_object->timecreated;
38fb8190 866 $tag_instance_object->tiuserid = $userid;
cc033d48 867
cfa2c6e1
MN
868 $tag_instance_object->id = $DB->insert_record('tag_instance', $tag_instance_object);
869 }
870
871 // We can not fire an event with 'null' as the contextid.
872 if (is_null($contextid)) {
873 $contextid = context_system::instance()->id;
c933a060 874 }
cfa2c6e1
MN
875
876 // Trigger item tagged event.
877 $event = \core\event\item_tagged::create(array(
878 'objectid' => $tag_instance_object->id,
879 'contextid' => $contextid,
880 'other' => array(
881 'tagid' => $tagid,
882 'tagname' => $tag->name,
883 'tagrawname' => $tag->rawname,
884 'itemid' => $record_id,
885 'itemtype' => $record_type
886 )
887 ));
888 $event->trigger();
889
890 return true;
c933a060 891}
892
893/**
db32b054 894 * Function that returns tags that start with some text, for use by the autocomplete feature
d4be9d6d 895 *
bcdcee90
GGC
896 * @package core_tag
897 * @access private
898 * @param string $text string that the tag names will be matched against
899 * @return mixed an array of objects, or false if no records were found or an error occured.
c933a060 900 */
db32b054 901function tag_autocomplete($text) {
f7ed2687 902 global $DB;
903 return $DB->get_records_sql("SELECT tg.id, tg.name, tg.rawname
904 FROM {tag} tg
2f1e464a 905 WHERE tg.name LIKE ?", array(core_text::strtolower($text)."%"));
c933a060 906}
907
986dca60 908/**
9545cdba 909 * Clean up the tag tables, making sure all tagged object still exists.
910 *
bcdcee90
GGC
911 * This should normally not be necessary, but in case related tags are not deleted when the tagged record is removed, this should be
912 * done once in a while, perhaps on an occasional cron run. On a site with lots of tags, this could become an expensive function to
913 * call: don't run at peak time.
914 *
915 * @package core_tag
916 * @access private
917 * @todo MDL-31212 Update tag cleanup sql so that it supports multiple types of tags
9545cdba 918 */
919function tag_cleanup() {
f7ed2687 920 global $DB;
9545cdba 921
f7ed2687 922 $instances = $DB->get_recordset('tag_instance');
9545cdba 923
084426c5 924 // cleanup tag instances
f7ed2687 925 foreach ($instances as $instance) {
9545cdba 926 $delete = false;
986dca60 927
f7ed2687 928 if (!$DB->record_exists('tag', array('id'=>$instance->tagid))) {
9545cdba 929 // if the tag has been removed, instance should be deleted.
930 $delete = true;
931 } else {
932 switch ($instance->itemtype) {
933 case 'user': // users are marked as deleted, but not actually deleted
f7ed2687 934 if ($DB->record_exists('user', array('id'=>$instance->itemid, 'deleted'=>1))) {
9545cdba 935 $delete = true;
936 }
937 break;
938 default: // anything else, if the instance is not there, delete.
f7ed2687 939 if (!$DB->record_exists($instance->itemtype, array('id'=>$instance->itemid))) {
9545cdba 940 $delete = true;
941 }
942 break;
943 }
944 }
945 if ($delete) {
946 tag_delete_instance($instance->itemtype, $instance->itemid, $instance->tagid);
947 //debugging('deleting tag_instance #'. $instance->id .', linked to tag id #'. $instance->tagid, DEBUG_DEVELOPER);
948 }
949 }
f7ed2687 950 $instances->close();
9545cdba 951
bcdcee90 952 // TODO MDL-31212 this will only clean tags of type 'default'. This is good as
9545cdba 953 // it won't delete 'official' tags, but the day we get more than two
954 // types, we need to fix this.
f7ed2687 955 $unused_tags = $DB->get_recordset_sql("SELECT tg.id
956 FROM {tag} tg
957 WHERE tg.tagtype = 'default'
958 AND NOT EXISTS (
959 SELECT 'x'
960 FROM {tag_instance} ti
961 WHERE ti.tagid = tg.id
962 )");
9545cdba 963
084426c5 964 // cleanup tags
f7ed2687 965 foreach ($unused_tags as $unused_tag) {
084426c5 966 tag_delete($unused_tag->id);
967 //debugging('deleting unused tag #'. $unused_tag->id, DEBUG_DEVELOPER);
9545cdba 968 }
f7ed2687 969 $unused_tags->close();
9545cdba 970}
971
c933a060 972/**
bcdcee90 973 * Calculates and stores the correlated tags of all tags. The correlations are stored in the 'tag_correlation' table.
db32b054 974 *
bcdcee90 975 * Two tags are correlated if they appear together a lot. Ex.: Users tagged with "computers" will probably also be tagged with "algorithms".
d4be9d6d 976 *
bcdcee90
GGC
977 * The rationale for the 'tag_correlation' table is performance. It works as a cache for a potentially heavy load query done at the
978 * 'tag_instance' table. So, the 'tag_correlation' table stores redundant information derived from the 'tag_instance' table.
d4be9d6d 979 *
bcdcee90
GGC
980 * @package core_tag
981 * @access private
982 * @param int $mincorrelation Only tags with more than $mincorrelation correlations will be identified.
c933a060 983 */
78defd5c 984function tag_compute_correlations($mincorrelation = 2) {
f7ed2687 985 global $DB;
3d436d8a 986
78defd5c
SH
987 // This mighty one line query fetches a row from the database for every
988 // individual tag correlation. We then need to process the rows collecting
989 // the correlations for each tag id.
990 // The fields used by this query are as follows:
991 // tagid : This is the tag id, there should be at least $mincorrelation
992 // rows for each tag id.
993 // correlation : This is the tag id that correlates to the above tagid field.
994 // correlationid : This is the id of the row in the tag_correlation table that
995 // relates to the tagid field and will be NULL if there are no
996 // existing correlations
2650c547 997 $sql = 'SELECT pairs.tagid, pairs.correlation, pairs.ocurrences, co.id AS correlationid
1c2cfff0
EL
998 FROM (
999 SELECT ta.tagid, tb.tagid AS correlation, COUNT(*) AS ocurrences
1000 FROM {tag_instance} ta
1001 JOIN {tag_instance} tb ON (ta.itemtype = tb.itemtype AND ta.itemid = tb.itemid AND ta.tagid <> tb.tagid)
1002 GROUP BY ta.tagid, tb.tagid
1003 HAVING COUNT(*) > :mincorrelation
1004 ) pairs
1005 LEFT JOIN {tag_correlation} co ON co.tagid = pairs.tagid
1006 ORDER BY pairs.tagid ASC, pairs.ocurrences DESC, pairs.correlation ASC';
78defd5c
SH
1007 $rs = $DB->get_recordset_sql($sql, array('mincorrelation' => $mincorrelation));
1008
1009 // Set up an empty tag correlation object
1010 $tagcorrelation = new stdClass;
1011 $tagcorrelation->id = null;
1012 $tagcorrelation->tagid = null;
1013 $tagcorrelation->correlatedtags = array();
1014
638cf615 1015 // We store each correlation id in this array so we can remove any correlations
2650c547
SH
1016 // that no longer exist.
1017 $correlations = array();
1018
78defd5c 1019 // Iterate each row of the result set and build them into tag correlations.
638cf615
AD
1020 // We add all of a tag's correlations to $tagcorrelation->correlatedtags[]
1021 // then save the $tagcorrelation object
78defd5c
SH
1022 foreach ($rs as $row) {
1023 if ($row->tagid != $tagcorrelation->tagid) {
638cf615 1024 // The tag id has changed so we have all of the correlations for this tag
2650c547
SH
1025 $tagcorrelationid = tag_process_computed_correlation($tagcorrelation);
1026 if ($tagcorrelationid) {
1027 $correlations[] = $tagcorrelationid;
1028 }
78defd5c
SH
1029 // Now we reset the tag correlation object so we can reuse it and set it
1030 // up for the current record.
1031 $tagcorrelation = new stdClass;
1032 $tagcorrelation->id = $row->correlationid;
1033 $tagcorrelation->tagid = $row->tagid;
1034 $tagcorrelation->correlatedtags = array();
db32b054 1035 }
638cf615 1036 //Save the correlation on the tag correlation object
78defd5c
SH
1037 $tagcorrelation->correlatedtags[] = $row->correlation;
1038 }
1039 // Update the current correlation after the last record.
2650c547
SH
1040 $tagcorrelationid = tag_process_computed_correlation($tagcorrelation);
1041 if ($tagcorrelationid) {
1042 $correlations[] = $tagcorrelationid;
1043 }
1044
c933a060 1045
78defd5c
SH
1046 // Close the recordset
1047 $rs->close();
2650c547
SH
1048
1049 // Remove any correlations that weren't just identified
638cf615
AD
1050 if (empty($correlations)) {
1051 //there are no tag correlations
1052 $DB->delete_records('tag_correlation');
1053 } else {
1054 list($sql, $params) = $DB->get_in_or_equal($correlations, SQL_PARAMS_NAMED, 'param0000', false);
1055 $DB->delete_records_select('tag_correlation', 'id '.$sql, $params);
1056 }
78defd5c 1057}
844f9c15 1058
78defd5c 1059/**
bcdcee90 1060 * This function processes a tag correlation and makes changes in the database as required.
78defd5c 1061 *
bcdcee90 1062 * The tag correlation object needs have both a tagid property and a correlatedtags property that is an array.
78defd5c 1063 *
bcdcee90
GGC
1064 * @package core_tag
1065 * @access private
1066 * @param stdClass $tagcorrelation
1067 * @return int/bool The id of the tag correlation that was just processed or false.
78defd5c
SH
1068 */
1069function tag_process_computed_correlation(stdClass $tagcorrelation) {
1070 global $DB;
db32b054 1071
78defd5c
SH
1072 // You must provide a tagid and correlatedtags must be set and be an array
1073 if (empty($tagcorrelation->tagid) || !isset($tagcorrelation->correlatedtags) || !is_array($tagcorrelation->correlatedtags)) {
1074 return false;
3d436d8a 1075 }
78defd5c 1076
78defd5c
SH
1077 $tagcorrelation->correlatedtags = join(',', $tagcorrelation->correlatedtags);
1078 if (!empty($tagcorrelation->id)) {
1079 // The tag correlation already exists so update it
1080 $DB->update_record('tag_correlation', $tagcorrelation);
1081 } else {
1082 // This is a new correlation to insert
2650c547 1083 $tagcorrelation->id = $DB->insert_record('tag_correlation', $tagcorrelation);
78defd5c 1084 }
2650c547 1085 return $tagcorrelation->id;
db32b054 1086}
1087
1088/**
1089 * Tasks that should be performed at cron time
bcdcee90
GGC
1090 *
1091 * @package core_tag
1092 * @access private
db32b054 1093 */
1094function tag_cron() {
1095 tag_compute_correlations();
0f5e5f5c 1096 tag_cleanup();
db32b054 1097}
1098
0f039283 1099/**
1100 * Search for tags with names that match some text
1101 *
bcdcee90
GGC
1102 * @package core_tag
1103 * @access private
1104 * @param string $text escaped string that the tag names will be matched against
1105 * @param bool $ordered If true, tags are ordered by their popularity. If false, no ordering.
1106 * @param int/string $limitfrom (optional, required if $limitnum is set) return a subset of records, starting at this point.
1107 * @param int/string $limitnum (optional, required if $limitfrom is set) return a subset comprising this many records.
1108 * @return array/boolean an array of objects, or false if no records were found or an error occured.
0f039283 1109 */
1110function tag_find_tags($text, $ordered=true, $limitfrom='', $limitnum='') {
f7ed2687 1111 global $DB;
0f039283 1112
7c2cc9c8
PS
1113 $norm = tag_normalize($text, TAG_CASE_LOWER);
1114 $text = array_shift($norm);
0f039283 1115
1116 if ($ordered) {
f7ed2687 1117 $query = "SELECT tg.id, tg.name, tg.rawname, COUNT(ti.id) AS count
1118 FROM {tag} tg LEFT JOIN {tag_instance} ti ON tg.id = ti.tagid
1119 WHERE tg.name LIKE ?
1120 GROUP BY tg.id, tg.name, tg.rawname
1121 ORDER BY count DESC";
0f039283 1122 } else {
f7ed2687 1123 $query = "SELECT tg.id, tg.name, tg.rawname
1124 FROM {tag} tg
1125 WHERE tg.name LIKE ?";
0f039283 1126 }
f7ed2687 1127 $params = array("%{$text}%");
1128 return $DB->get_records_sql($query, $params, $limitfrom , $limitnum);
0f039283 1129}
1130
986dca60 1131/**
db32b054 1132 * Get the name of a tag
986dca60 1133 *
bcdcee90
GGC
1134 * @package core_tag
1135 * @access private
1136 * @param mixed $tagids the id of the tag, or an array of ids
1137 * @return mixed string name of one tag, or id-indexed array of strings
db32b054 1138 */
1139function tag_get_name($tagids) {
f7ed2687 1140 global $DB;
3d436d8a 1141
f7ed2687 1142 if (!is_array($tagids)) {
1143 if ($tag = $DB->get_record('tag', array('id'=>$tagids))) {
1144 return $tag->name;
1145 }
1146 return false;
db32b054 1147 }
c933a060 1148
db32b054 1149 $tag_names = array();
986dca60 1150 foreach($DB->get_records_list('tag', 'id', $tagids) as $tag) {
db32b054 1151 $tag_names[$tag->id] = $tag->name;
1152 }
c933a060 1153
db32b054 1154 return $tag_names;
c933a060 1155}
1156
1157/**
bcdcee90
GGC
1158 * Returns the correlated tags of a tag, retrieved from the tag_correlation table. Make sure cron runs, otherwise the table will be
1159 * empty and this function won't return anything.
c933a060 1160 *
bcdcee90
GGC
1161 * @package core_tag
1162 * @access private
1163 * @param int $tag_id is a single tag id
1164 * @param int $limitnum this parameter does not appear to have any function???
1165 * @return array an array of tag objects or an empty if no correlated tags are found
c933a060 1166 */
db32b054 1167function tag_get_correlated($tag_id, $limitnum=null) {
f7ed2687 1168 global $DB;
3d436d8a 1169
f7ed2687 1170 $tag_correlation = $DB->get_record('tag_correlation', array('tagid'=>$tag_id));
c933a060 1171
db32b054 1172 if (!$tag_correlation || empty($tag_correlation->correlatedtags)) {
1173 return array();
c933a060 1174 }
986dca60 1175
73c32e86 1176 // this is (and has to) return the same fields as the query in tag_get_tags
638cf615 1177 $sql = "SELECT DISTINCT tg.id, tg.tagtype, tg.name, tg.rawname, tg.flag, ti.ordering
e2a64d83 1178 FROM {tag} tg
638cf615 1179 INNER JOIN {tag_instance} ti ON tg.id = ti.tagid
e2a64d83
SH
1180 WHERE tg.id IN ({$tag_correlation->correlatedtags})";
1181 $result = $DB->get_records_sql($sql);
1182 if (!$result) {
db32b054 1183 return array();
c933a060 1184 }
986dca60 1185
db32b054 1186 return $result;
c933a060 1187}
1188
c933a060 1189/**
db32b054 1190 * Function that normalizes a list of tag names.
c933a060 1191 *
bcdcee90
GGC
1192 * @package core_tag
1193 * @access private
1194 * @param array/string $rawtags array of tags, or a single tag.
1195 * @param int $case case to use for returned value (default: lower case). Either TAG_CASE_LOWER (default) or TAG_CASE_ORIGINAL
1196 * @return array lowercased normalized tags, indexed by the normalized tag, in the same order as the original array.
1197 * (Eg: 'Banana' => 'banana').
c933a060 1198 */
db32b054 1199function tag_normalize($rawtags, $case = TAG_CASE_LOWER) {
1200
0f039283 1201 // cache normalized tags, to prevent costly repeated calls to clean_param
db32b054 1202 static $cleaned_tags_lc = array(); // lower case - use for comparison
1203 static $cleaned_tags_mc = array(); // mixed case - use for saving to database
c933a060 1204
db32b054 1205 if ( !is_array($rawtags) ) {
1206 $rawtags = array($rawtags);
1207 }
c933a060 1208
db32b054 1209 $result = array();
1210 foreach($rawtags as $rawtag) {
1211 $rawtag = trim($rawtag);
1212 if (!$rawtag) {
1213 continue;
1214 }
1215 if ( !array_key_exists($rawtag, $cleaned_tags_lc) ) {
2f1e464a 1216 $cleaned_tags_lc[$rawtag] = core_text::strtolower( clean_param($rawtag, PARAM_TAG) );
db32b054 1217 $cleaned_tags_mc[$rawtag] = clean_param($rawtag, PARAM_TAG);
1218 }
986dca60 1219 if ( $case == TAG_CASE_LOWER ) {
db32b054 1220 $result[$rawtag] = $cleaned_tags_lc[$rawtag];
1221 } else { // TAG_CASE_ORIGINAL
1222 $result[$rawtag] = $cleaned_tags_mc[$rawtag];
1223 }
1224 }
986dca60 1225
db32b054 1226 return $result;
c933a060 1227}
1228
1229/**
bcdcee90 1230 * Count how many records are tagged with a specific tag.
c933a060 1231 *
bcdcee90
GGC
1232 * @package core_tag
1233 * @access private
1234 * @param string $record_type record to look for ('post', 'user', etc.)
1235 * @param int $tagid is a single tag id
1236 * @return int number of mathing tags.
c933a060 1237 */
0f039283 1238function tag_record_count($record_type, $tagid) {
f7ed2687 1239 global $DB;
1240 return $DB->count_records('tag_instance', array('itemtype'=>$record_type, 'tagid'=>$tagid));
0f039283 1241}
c933a060 1242
0f039283 1243/**
986dca60 1244 * Determine if a record is tagged with a specific tag
0f039283 1245 *
bcdcee90
GGC
1246 * @package core_tag
1247 * @access private
1248 * @param string $record_type the record type to look for
1249 * @param int $record_id the record id to look for
1250 * @param string $tag a tag name
1251 * @return bool/int true if it is tagged, 0 (false) otherwise
0f039283 1252 */
1253function tag_record_tagged_with($record_type, $record_id, $tag) {
f7ed2687 1254 global $DB;
0f039283 1255 if ($tagid = tag_get_id($tag)) {
f7ed2687 1256 return $DB->count_records('tag_instance', array('itemtype'=>$record_type, 'itemid'=>$record_id, 'tagid'=>$tagid));
c933a060 1257 } else {
0f039283 1258 return 0; // tag doesn't exist
c933a060 1259 }
c933a060 1260}
1261
1262/**
6298494d 1263 * Flag a tag as inappropriate.
986dca60 1264 *
6298494d 1265 * @param int|array $tagids a single tagid, or an array of tagids
c933a060 1266 */
db32b054 1267function tag_set_flag($tagids) {
f7ed2687 1268 global $DB;
1269
6298494d
MN
1270 $tagids = (array) $tagids;
1271
1272 // Use the tagids to create a select statement to be used later.
1273 list($tagsql, $tagparams) = $DB->get_in_or_equal($tagids, SQL_PARAMS_NAMED);
1274
1275 // Update all the tags to flagged.
1276 $sql = "UPDATE {tag}
1277 SET flag = flag + 1, timemodified = :time
1278 WHERE id $tagsql";
1279
1280 // Update all the tags.
1281 $DB->execute($sql, array_merge(array('time' => time()), $tagparams));
1282
1283 // Get all the tags.
1284 if ($tags = $DB->get_records_select('tag', 'id '. $tagsql, $tagparams, 'id ASC')) {
1285 // Loop through and fire an event for each tag that it was flagged.
1286 foreach ($tags as $tag) {
1287 $event = \core\event\tag_flagged::create(array(
1288 'objectid' => $tag->id,
1289 'relateduserid' => $tag->userid,
1290 'context' => context_system::instance(),
1291 'other' => array(
1292 'name' => $tag->name,
1293 'rawname' => $tag->rawname
1294 )
1295
1296 ));
1297 $event->add_record_snapshot('tag', $tag);
1298 $event->trigger();
1299 }
c933a060 1300 }
1301}
1302
986dca60 1303/**
097bd4cd 1304 * Remove the inappropriate flag on a tag.
986dca60 1305 *
097bd4cd 1306 * @param int|array $tagids a single tagid, or an array of tagids
c933a060 1307 */
db32b054 1308function tag_unset_flag($tagids) {
f7ed2687 1309 global $DB;
d4be9d6d 1310
097bd4cd
MN
1311 $tagids = (array) $tagids;
1312
1313 // Use the tagids to create a select statement to be used later.
1314 list($tagsql, $tagparams) = $DB->get_in_or_equal($tagids, SQL_PARAMS_NAMED);
1315
1316 // Update all the tags to unflagged.
1317 $sql = "UPDATE {tag}
1318 SET flag = 0, timemodified = :time
1319 WHERE id $tagsql";
1320
1321 // Update all the tags.
1322 $DB->execute($sql, array_merge(array('time' => time()), $tagparams));
1323
1324 // Get all the tags.
1325 if ($tags = $DB->get_records_select('tag', 'id '. $tagsql, $tagparams, 'id ASC')) {
1326 // Loop through and fire an event for each tag that it was unflagged.
1327 foreach ($tags as $tag) {
1328 $event = \core\event\tag_unflagged::create(array(
1329 'objectid' => $tag->id,
1330 'relateduserid' => $tag->userid,
1331 'context' => context_system::instance(),
1332 'other' => array(
1333 'name' => $tag->name,
1334 'rawname' => $tag->rawname
1335 )
1336 ));
1337 $event->add_record_snapshot('tag', $tag);
1338 $event->trigger();
1339 }
ab86d9c7 1340 }
c933a060 1341}
b1627a92 1342
b1627a92
DC
1343/**
1344 * Return a list of page types
bcdcee90
GGC
1345 *
1346 * @package core_tag
1347 * @access private
1348 * @param string $pagetype current page type
1349 * @param stdClass $parentcontext Block's parent context
1350 * @param stdClass $currentcontext Current context of block
b1627a92 1351 */
b38e2e28 1352function tag_page_type_list($pagetype, $parentcontext, $currentcontext) {
b1627a92
DC
1353 return array(
1354 'tag-*'=>get_string('page-tag-x', 'tag'),
1355 'tag-index'=>get_string('page-tag-index', 'tag'),
1356 'tag-search'=>get_string('page-tag-search', 'tag'),
1357 'tag-manage'=>get_string('page-tag-manage', 'tag')
1358 );
1359}