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   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   * Class core_tag_area for managing tag areas
  19   *
  20   * @package   core_tag
  21   * @copyright 2015 Marina Glancy
  22   * @license   http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  23   */
  24  
  25  defined('MOODLE_INTERNAL') || die();
  26  
  27  /**
  28   * Class to manage tag areas
  29   *
  30   * @package   core_tag
  31   * @copyright 2015 Marina Glancy
  32   * @license   http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  33   */
  34  class core_tag_area {
  35  
  36      /**
  37       * Returns the list of areas indexed by itemtype and component
  38       *
  39       * @param int $tagcollid return only areas in this tag collection
  40       * @param bool $enabledonly return only enabled tag areas
  41       * @return array itemtype=>component=>tagarea object
  42       */
  43      public static function get_areas($tagcollid = null, $enabledonly = false) {
  44          global $DB;
  45          $cache = cache::make('core', 'tags');
  46          if (($itemtypes = $cache->get('tag_area')) === false) {
  47              $colls = core_tag_collection::get_collections();
  48              $defaultcoll = reset($colls);
  49              $itemtypes = array();
  50              $areas = $DB->get_records('tag_area', array(), 'component,itemtype');
  51              foreach ($areas as $area) {
  52                  if ($colls[$area->tagcollid]->component) {
  53                      $area->locked = true;
  54                  }
  55                  $itemtypes[$area->itemtype][$area->component] = $area;
  56              }
  57              $cache->set('tag_area', $itemtypes);
  58          }
  59          if ($tagcollid || $enabledonly) {
  60              $rv = array();
  61              foreach ($itemtypes as $itemtype => $it) {
  62                  foreach ($it as $component => $v) {
  63                      if (($v->tagcollid == $tagcollid || !$tagcollid) && (!$enabledonly || $v->enabled)) {
  64                          $rv[$itemtype][$component] = $v;
  65                      }
  66                  }
  67              }
  68              return $rv;
  69          }
  70          return $itemtypes;
  71      }
  72  
  73      /**
  74       * Retrieves info about one tag area
  75       *
  76       * @param int $tagareaid
  77       * @return stdClass
  78       */
  79      public static function get_by_id($tagareaid) {
  80          $tagareas = self::get_areas();
  81          foreach ($tagareas as $itemtype => $it) {
  82              foreach ($it as $component => $v) {
  83                  if ($v->id == $tagareaid) {
  84                      return $v;
  85                  }
  86              }
  87          }
  88          return null;
  89      }
  90  
  91      /**
  92       * Returns the display name for this area
  93       *
  94       * @param string $component
  95       * @param string $itemtype
  96       * @return lang_string
  97       */
  98      public static function display_name($component, $itemtype) {
  99          $identifier = 'tagarea_' . clean_param($itemtype, PARAM_STRINGID);
 100          if ($component === 'core') {
 101              $component = 'tag';
 102          }
 103          return new lang_string($identifier, $component);
 104      }
 105  
 106      /**
 107       * Returns whether the tag area is enabled
 108       *
 109       * @param string $component component responsible for tagging
 110       * @param string $itemtype what is being tagged, for example, 'post', 'course', 'user', etc.
 111       * @return bool|null
 112       */
 113      public static function is_enabled($component, $itemtype) {
 114          global $CFG;
 115          if (empty($CFG->usetags)) {
 116              return false;
 117          }
 118          $itemtypes = self::get_areas();
 119          if (isset($itemtypes[$itemtype][$component])) {
 120              return $itemtypes[$itemtype][$component]->enabled ? true : false;
 121          }
 122          return null;
 123      }
 124  
 125      /**
 126       * Returns the id of the tag collection that should be used for storing tags of this itemtype
 127       *
 128       * @param string $component component responsible for tagging
 129       * @param string $itemtype what is being tagged, for example, 'post', 'course', 'user', etc.
 130       * @return int
 131       */
 132      public static function get_collection($component, $itemtype) {
 133          $itemtypes = self::get_areas();
 134          if (array_key_exists($itemtype, $itemtypes)) {
 135              if (!array_key_exists($component, $itemtypes[$itemtype])) {
 136                  $component = key($itemtypes[$itemtype]);
 137              }
 138              return $itemtypes[$itemtype][$component]->tagcollid;
 139          }
 140          return core_tag_collection::get_default();
 141      }
 142  
 143      /**
 144       * Returns wether this tag area should display or not standard tags when user edits it.
 145       *
 146       * @param string $component component responsible for tagging
 147       * @param string $itemtype what is being tagged, for example, 'post', 'course', 'user', etc.
 148       * @return int
 149       */
 150      public static function get_showstandard($component, $itemtype) {
 151          $itemtypes = self::get_areas();
 152          if (array_key_exists($itemtype, $itemtypes)) {
 153              if (!array_key_exists($component, $itemtypes[$itemtype])) {
 154                  $component = key($itemtypes[$itemtype]);
 155              }
 156              return $itemtypes[$itemtype][$component]->showstandard;
 157          }
 158          return core_tag_tag::BOTH_STANDARD_AND_NOT;
 159      }
 160  
 161      /**
 162       * Returns all tag areas and collections that are currently cached in DB for this component
 163       *
 164       * @param string $componentname
 165       * @return array first element is the list of areas and the second list of collections
 166       */
 167      protected static function get_definitions_for_component($componentname) {
 168          global $DB;
 169          list($a, $b) = core_component::normalize_component($componentname);
 170          $component = $b ? ($a . '_' . $b) : $a;
 171          $sql = 'component = :component';
 172          $params = array('component' => $component);
 173          if ($component === 'core') {
 174              $sql .= ' OR component LIKE :coreprefix';
 175              $params['coreprefix'] = 'core_%';
 176          }
 177          $fields = $DB->sql_concat_join("':'", array('itemtype', 'component'));
 178          $existingareas = $DB->get_records_sql(
 179                  "SELECT $fields AS returnkey, a.* FROM {tag_area} a WHERE $sql", $params);
 180          $fields = $DB->sql_concat_join("':'", array('name', 'component'));
 181          $existingcolls = $DB->get_records_sql(
 182                  "SELECT $fields AS returnkey, t.* FROM {tag_coll} t WHERE $sql", $params);
 183          return array($existingareas, $existingcolls);
 184  
 185      }
 186  
 187      /**
 188       * Completely delete a tag area and all instances inside it
 189       *
 190       * @param stdClass $record
 191       */
 192      protected static function delete($record) {
 193          global $DB;
 194  
 195          core_tag_tag::delete_instances($record->component, $record->itemtype);
 196  
 197          $DB->delete_records('tag_area',
 198                  array('itemtype' => $record->itemtype,
 199                      'component' => $record->component));
 200  
 201          // Reset cache.
 202          cache::make('core', 'tags')->delete('tag_area');
 203      }
 204  
 205      /**
 206       * Create a new tag area
 207       *
 208       * @param stdClass $record
 209       */
 210      protected static function create($record) {
 211          global $DB;
 212          if (empty($record->tagcollid)) {
 213              $record->tagcollid = core_tag_collection::get_default();
 214          }
 215          $DB->insert_record('tag_area', array('component' => $record->component,
 216              'itemtype' => $record->itemtype,
 217              'tagcollid' => $record->tagcollid,
 218              'callback' => $record->callback,
 219              'callbackfile' => $record->callbackfile,
 220              'showstandard' => isset($record->showstandard) ? $record->showstandard : core_tag_tag::BOTH_STANDARD_AND_NOT));
 221  
 222          // Reset cache.
 223          cache::make('core', 'tags')->delete('tag_area');
 224      }
 225  
 226      /**
 227       * Update the tag area
 228       *
 229       * @param stdClass $existing current record from DB table tag_area
 230       * @param array|stdClass $data fields that need updating
 231       */
 232      public static function update($existing, $data) {
 233          global $DB;
 234          $data = array_intersect_key((array)$data,
 235                  array('enabled' => 1, 'tagcollid' => 1,
 236                      'callback' => 1, 'callbackfile' => 1, 'showstandard' => 1));
 237          foreach ($data as $key => $value) {
 238              if ($existing->$key == $value) {
 239                  unset($data[$key]);
 240              }
 241          }
 242          if (!$data) {
 243              return;
 244          }
 245  
 246          if (!empty($data['tagcollid'])) {
 247              self::move_tags($existing->component, $existing->itemtype, $data['tagcollid']);
 248          }
 249  
 250          $data['id'] = $existing->id;
 251          $DB->update_record('tag_area', $data);
 252  
 253          // Reset cache.
 254          cache::make('core', 'tags')->delete('tag_area');
 255      }
 256  
 257      /**
 258       * Update the database to contain a list of tagged areas for a component.
 259       * The list of tagged areas is read from [plugindir]/db/tag.php
 260       *
 261       * @param string $componentname - The frankenstyle component name.
 262       */
 263      public static function reset_definitions_for_component($componentname) {
 264          global $DB;
 265          $dir = core_component::get_component_directory($componentname);
 266          $file = $dir . '/db/tag.php';
 267          $tagareas = null;
 268          if (file_exists($file)) {
 269              require_once($file);
 270          }
 271  
 272          list($a, $b) = core_component::normalize_component($componentname);
 273          $component = $b ? ($a . '_' . $b) : $a;
 274  
 275          list($existingareas, $existingcolls) = self::get_definitions_for_component($componentname);
 276  
 277          $itemtypes = array();
 278          $collections = array();
 279          $needcleanup = false;
 280          if ($tagareas) {
 281              foreach ($tagareas as $tagarea) {
 282                  $record = (object)$tagarea;
 283                  if ($component !== 'core' || empty($record->component)) {
 284                      if (isset($record->component) && $record->component !== $component) {
 285                          debugging("Item type {$record->itemtype} has illegal component {$record->component}", DEBUG_DEVELOPER);
 286                      }
 287                      $record->component = $component;
 288                  }
 289                  unset($record->tagcollid);
 290                  if (!empty($record->collection)) {
 291                      // Create collection if it does not exist, or update 'searchable' and/or 'customurl' if needed.
 292                      $key = $record->collection . ':' . $record->component;
 293                      $collectiondata = array_intersect_key((array)$record,
 294                              array('component' => 1, 'searchable' => 1, 'customurl' => 1));
 295                      $collectiondata['name'] = $record->collection;
 296                      if (!array_key_exists($key, $existingcolls)) {
 297                          $existingcolls[$key] = core_tag_collection::create($collectiondata);
 298                      } else {
 299                          core_tag_collection::update($existingcolls[$key], $collectiondata);
 300                      }
 301                      $record->tagcollid = $existingcolls[$key]->id;
 302                      $collections[$key] = $existingcolls[$key];
 303                      unset($record->collection);
 304                  }
 305                  unset($record->searchable);
 306                  unset($record->customurl);
 307                  if (!isset($record->callback)) {
 308                      $record->callback = null;
 309                  }
 310                  if (!isset($record->callbackfile)) {
 311                      $record->callbackfile = null;
 312                  }
 313                  $itemtypes[$record->itemtype . ':' . $record->component] = $record;
 314              }
 315          }
 316          $todeletearea = array_diff_key($existingareas, $itemtypes);
 317          $todeletecoll = array_diff_key($existingcolls, $collections);
 318  
 319          // Delete tag areas that are no longer needed.
 320          foreach ($todeletearea as $key => $record) {
 321              self::delete($record);
 322          }
 323  
 324          // Update tag areas if changed.
 325          $toupdatearea = array_intersect_key($existingareas, $itemtypes);
 326          foreach ($toupdatearea as $key => $tagarea) {
 327              if (!isset($itemtypes[$key]->tagcollid)) {
 328                  foreach ($todeletecoll as $tagcoll) {
 329                      if ($tagcoll->id == $tagarea->tagcollid) {
 330                          $itemtypes[$key]->tagcollid = core_tag_collection::get_default();
 331                      }
 332                  }
 333              }
 334              unset($itemtypes[$key]->showstandard); // Do not override value that was already changed by admin with the default.
 335              self::update($tagarea, $itemtypes[$key]);
 336          }
 337  
 338          // Create new tag areas.
 339          $toaddarea = array_diff_key($itemtypes, $existingareas);
 340          foreach ($toaddarea as $record) {
 341              self::create($record);
 342          }
 343  
 344          // Delete tag collections that are no longer needed.
 345          foreach ($todeletecoll as $key => $tagcoll) {
 346              core_tag_collection::delete($tagcoll);
 347          }
 348      }
 349  
 350      /**
 351       * Deletes all tag areas, collections and instances associated with the plugin.
 352       *
 353       * @param string $pluginname
 354       */
 355      public static function uninstall($pluginname) {
 356          global $DB;
 357  
 358          list($a, $b) = core_component::normalize_component($pluginname);
 359          if (empty($b) || $a === 'core') {
 360              throw new coding_exception('Core component can not be uninstalled');
 361          }
 362          $component = $a . '_' . $b;
 363  
 364          core_tag_tag::delete_instances($component);
 365  
 366          $DB->delete_records('tag_area', array('component' => $component));
 367          $DB->delete_records('tag_coll', array('component' => $component));
 368          cache::make('core', 'tags')->delete_many(array('tag_area', 'tag_coll'));
 369      }
 370  
 371      /**
 372       * Moves existing tags associated with an item type to another tag collection
 373       *
 374       * @param string $component
 375       * @param string $itemtype
 376       * @param int $tagcollid
 377       */
 378      public static function move_tags($component, $itemtype, $tagcollid) {
 379          global $DB;
 380          $params = array('itemtype1' => $itemtype, 'component1' => $component,
 381              'itemtype2' => $itemtype, 'component2' => $component,
 382              'tagcollid1' => $tagcollid, 'tagcollid2' => $tagcollid);
 383  
 384          // Find all collections that need to be cleaned later.
 385          $sql = "SELECT DISTINCT t.tagcollid " .
 386              "FROM {tag_instance} ti " .
 387              "JOIN {tag} t ON t.id = ti.tagid AND t.tagcollid <> :tagcollid1 " .
 388              "WHERE ti.itemtype = :itemtype2 AND ti.component = :component2 ";
 389          $cleanupcollections = $DB->get_fieldset_sql($sql, $params);
 390  
 391          // Find all tags that are related to the tags being moved and make sure they are present in the target tagcoll.
 392          // This query is a little complicated because Oracle does not allow to run SELECT DISTINCT on CLOB fields.
 393          $sql = "SELECT name, rawname, description, descriptionformat, userid, isstandard, flag, timemodified ".
 394                  "FROM {tag} WHERE id IN ".
 395                  "(SELECT r.id ".
 396                  "FROM {tag_instance} ti ". // Instances that need moving.
 397                  "JOIN {tag} t ON t.id = ti.tagid AND t.tagcollid <> :tagcollid1 ". // Tags that need moving.
 398                  "JOIN {tag_instance} tr ON tr.itemtype = 'tag' and tr.component = 'core' AND tr.itemid = t.id ".
 399                  "JOIN {tag} r ON r.id = tr.tagid ". // Tags related to the tags that need moving.
 400                  "LEFT JOIN {tag} re ON re.name = r.name AND re.tagcollid = :tagcollid2 ". // Existing tags in the target tagcoll with the same name as related tags.
 401                  "WHERE ti.itemtype = :itemtype2 AND ti.component = :component2 ".
 402                  "    AND re.id IS NULL)"; // We need related tags that ARE NOT present in the target tagcoll.
 403          $result = $DB->get_records_sql($sql, $params);
 404          foreach ($result as $tag) {
 405              $tag->tagcollid = $tagcollid;
 406              $tag->id = $DB->insert_record('tag', $tag);
 407              \core\event\tag_created::create_from_tag($tag);
 408          }
 409  
 410          // Find all tags that need moving and have related tags, remember their related tags.
 411          $sql = "SELECT t.name AS tagname, r.rawname AS relatedtag ".
 412                  "FROM {tag_instance} ti ". // Instances that need moving.
 413                  "JOIN {tag} t ON t.id = ti.tagid AND t.tagcollid <> :tagcollid1 ". // Tags that need moving.
 414                  "JOIN {tag_instance} tr ON t.id = tr.tagid AND tr.itemtype = 'tag' and tr.component = 'core' ".
 415                  "JOIN {tag} r ON r.id = tr.itemid ". // Tags related to the tags that need moving.
 416                  "WHERE ti.itemtype = :itemtype2 AND ti.component = :component2 ".
 417                  "ORDER BY t.id, tr.ordering ";
 418          $relatedtags = array();
 419          $result = $DB->get_recordset_sql($sql, $params);
 420          foreach ($result as $record) {
 421              $relatedtags[$record->tagname][] = $record->relatedtag;
 422          }
 423          $result->close();
 424  
 425          // Find all tags that are used for this itemtype/component and are not present in the target tag collection.
 426          // This query is a little complicated because Oracle does not allow to run SELECT DISTINCT on CLOB fields.
 427          $sql = "SELECT id, name, rawname, description, descriptionformat, userid, isstandard, flag, timemodified
 428                  FROM {tag} WHERE id IN
 429                  (SELECT t.id
 430                  FROM {tag_instance} ti
 431                  JOIN {tag} t ON t.id = ti.tagid AND t.tagcollid <> :tagcollid1
 432                  LEFT JOIN {tag} tt ON tt.name = t.name AND tt.tagcollid = :tagcollid2
 433                  WHERE ti.itemtype = :itemtype2 AND ti.component = :component2
 434                      AND tt.id IS NULL)";
 435          $movedtags = array(); // Keep track of moved tags so we don't hit DB index violation.
 436          $result = $DB->get_records_sql($sql, $params);
 437          foreach ($result as $tag) {
 438              $originaltagid = $tag->id;
 439              if (array_key_exists($tag->name, $movedtags)) {
 440                  // Case of corrupted data when the same tag was in several collections.
 441                  $tag->id = $movedtags[$tag->name];
 442              } else {
 443                  // Copy the tag into the new collection.
 444                  unset($tag->id);
 445                  $tag->tagcollid = $tagcollid;
 446                  $tag->id = $DB->insert_record('tag', $tag);
 447                  \core\event\tag_created::create_from_tag($tag);
 448                  $movedtags[$tag->name] = $tag->id;
 449              }
 450              $DB->execute("UPDATE {tag_instance} SET tagid = ? WHERE tagid = ? AND itemtype = ? AND component = ?",
 451                      array($tag->id, $originaltagid, $itemtype, $component));
 452          }
 453  
 454          // Find all tags that are used for this itemtype/component and are already present in the target tag collection.
 455          $sql = "SELECT DISTINCT t.id, tt.id AS targettagid
 456                  FROM {tag_instance} ti
 457                  JOIN {tag} t ON t.id = ti.tagid AND t.tagcollid <> :tagcollid1
 458                  JOIN {tag} tt ON tt.name = t.name AND tt.tagcollid = :tagcollid2
 459                  WHERE ti.itemtype = :itemtype2 AND ti.component = :component2";
 460          $result = $DB->get_records_sql($sql, $params);
 461          foreach ($result as $tag) {
 462              $DB->execute("UPDATE {tag_instance} SET tagid = ? WHERE tagid = ? AND itemtype = ? AND component = ?",
 463                      array($tag->targettagid, $tag->id, $itemtype, $component));
 464          }
 465  
 466          // Add related tags to the moved tags.
 467          if ($relatedtags) {
 468              $tags = core_tag_tag::get_by_name_bulk($tagcollid, array_keys($relatedtags));
 469              foreach ($tags as $tag) {
 470                  $tag->add_related_tags($relatedtags[$tag->name]);
 471              }
 472          }
 473  
 474          if ($cleanupcollections) {
 475              core_tag_collection::cleanup_unused_tags($cleanupcollections);
 476          }
 477  
 478          // Reset caches.
 479          cache::make('core', 'tags')->delete('tag_area');
 480      }
 481  }