includes/WatchedItem.php

   1 <?php
   2 /**
   3  * Accessor and mutator for watchlist entries.
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation; either version 2 of the License, or
   8  * (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License along
  16  * with this program; if not, write to the Free Software Foundation, Inc.,
  17  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  18  * http://www.gnu.org/copyleft/gpl.html
  19  *
  20  * @file
  21  * @ingroup Watchlist
  22  */
  23
  24 /**
  25  * Representation of a pair of user and title for watchlist entries.
  26  *
  27  * @ingroup Watchlist
  28  */
  29 class WatchedItem {
  30         /**
  31          * Constant to specify that user rights 'editmywatchlist' and
  32          * 'viewmywatchlist' should not be checked.
  33          * @since 1.22
  34          */
  35         const IGNORE_USER_RIGHTS = 0;
  36
  37         /**
  38          * Constant to specify that user rights 'editmywatchlist' and
  39          * 'viewmywatchlist' should be checked.
  40          * @since 1.22
  41          */
  42         const CHECK_USER_RIGHTS = 1;
  43
  44         /** @var Title */
  45         public $mTitle;
  46
  47         /** @var User */
  48         public $mUser;
  49
  50         /** @var int */
  51         public $mCheckRights;
  52
  53         /** @var bool */
  54         private $loaded = false;
  55
  56         /** @var bool */
  57         private $watched;
  58
  59         /** @var string */
  60         private $timestamp;
  61
  62         /**
  63          * Create a WatchedItem object with the given user and title
  64          * @since 1.22 $checkRights parameter added
  65          * @param User $user The user to use for (un)watching
  66          * @param Title $title The title we're going to (un)watch
  67          * @param int $checkRights Whether to check the 'viewmywatchlist' and 'editmywatchlist' rights.
  68          *     Pass either WatchedItem::IGNORE_USER_RIGHTS or WatchedItem::CHECK_USER_RIGHTS.
  69          * @return WatchedItem
  70          */
  71         public static function fromUserTitle( $user, $title,
  72                 $checkRights = WatchedItem::CHECK_USER_RIGHTS
  73         ) {
  74                 $wl = new WatchedItem;
  75                 $wl->mUser = $user;
  76                 $wl->mTitle = $title;
  77                 $wl->mCheckRights = $checkRights;
  78
  79                 return $wl;
  80         }
  81
  82         /**
  83          * Title being watched
  84          * @return Title
  85          */
  86         protected function getTitle() {
  87                 return $this->mTitle;
  88         }
  89
  90         /**
  91          * Helper to retrieve the title namespace
  92          * @return int
  93          */
  94         protected function getTitleNs() {
  95                 return $this->getTitle()->getNamespace();
  96         }
  97
  98         /**
  99          * Helper to retrieve the title DBkey
 100          * @return string
 101          */
 102         protected function getTitleDBkey() {
 103                 return $this->getTitle()->getDBkey();
 104         }
 105
 106         /**
 107          * Helper to retrieve the user id
 108          * @return int
 109          */
 110         protected function getUserId() {
 111                 return $this->mUser->getId();
 112         }
 113
 114         /**
 115          * Return an array of conditions to select or update the appropriate database
 116          * row.
 117          *
 118          * @return array
 119          */
 120         private function dbCond() {
 121                 return array(
 122                         'wl_user' => $this->getUserId(),
 123                         'wl_namespace' => $this->getTitleNs(),
 124                         'wl_title' => $this->getTitleDBkey(),
 125                 );
 126         }
 127
 128         /**
 129          * Load the object from the database
 130          */
 131         private function load() {
 132                 if ( $this->loaded ) {
 133                         return;
 134                 }
 135                 $this->loaded = true;
 136
 137                 // Only loggedin user can have a watchlist
 138                 if ( $this->mUser->isAnon() ) {
 139                         $this->watched = false;
 140                         return;
 141                 }
 142
 143                 // some pages cannot be watched
 144                 if ( !$this->getTitle()->isWatchable() ) {
 145                         $this->watched = false;
 146                         return;
 147                 }
 148
 149                 # Pages and their talk pages are considered equivalent for watching;
 150                 # remember that talk namespaces are numbered as page namespace+1.
 151
 152                 $dbr = wfGetDB( DB_SLAVE );
 153                 $row = $dbr->selectRow( 'watchlist', 'wl_notificationtimestamp',
 154                         $this->dbCond(), __METHOD__ );
 155
 156                 if ( $row === false ) {
 157                         $this->watched = false;
 158                 } else {
 159                         $this->watched = true;
 160                         $this->timestamp = $row->wl_notificationtimestamp;
 161                 }
 162         }
 163
 164         /**
 165          * Check permissions
 166          * @param string $what 'viewmywatchlist' or 'editmywatchlist'
 167          */
 168         private function isAllowed( $what ) {
 169                 return !$this->mCheckRights || $this->mUser->isAllowed( $what );
 170         }
 171
 172         /**
 173          * Is mTitle being watched by mUser?
 174          * @return bool
 175          */
 176         public function isWatched() {
 177                 if ( !$this->isAllowed( 'viewmywatchlist' ) ) {
 178                         return false;
 179                 }
 180
 181                 $this->load();
 182                 return $this->watched;
 183         }
 184
 185         /**
 186          * Get the notification timestamp of this entry.
 187          *
 188          * @return bool|null|string False if the page is not watched, the value of
 189          *   the wl_notificationtimestamp field otherwise
 190          */
 191         public function getNotificationTimestamp() {
 192                 if ( !$this->isAllowed( 'viewmywatchlist' ) ) {
 193                         return false;
 194                 }
 195
 196                 $this->load();
 197                 if ( $this->watched ) {
 198                         return $this->timestamp;
 199                 } else {
 200                         return false;
 201                 }
 202         }
 203
 204         /**
 205          * Reset the notification timestamp of this entry
 206          *
 207          * @param bool $force Whether to force the write query to be executed even if the
 208          *    page is not watched or the notification timestamp is already NULL.
 209          * @param int $oldid The revision id being viewed. If not given or 0, latest revision is assumed.
 210          */
 211         public function resetNotificationTimestamp( $force = '', $oldid = 0 ) {
 212                 // Only loggedin user can have a watchlist
 213                 if ( wfReadOnly() || $this->mUser->isAnon() || !$this->isAllowed( 'editmywatchlist' ) ) {
 214                         return;
 215                 }
 216
 217                 if ( $force != 'force' ) {
 218                         $this->load();
 219                         if ( !$this->watched || $this->timestamp === null ) {
 220                                 return;
 221                         }
 222                 }
 223
 224                 $title = $this->getTitle();
 225                 if ( !$oldid ) {
 226                         // No oldid given, assuming latest revision; clear the timestamp.
 227                         $notificationTimestamp = null;
 228                 } elseif ( !$title->getNextRevisionID( $oldid ) ) {
 229                         // Oldid given and is the latest revision for this title; clear the timestamp.
 230                         $notificationTimestamp = null;
 231                 } else {
 232                         // See if the version marked as read is more recent than the one we're viewing.
 233                         // Call load() if it wasn't called before due to $force.
 234                         $this->load();
 235
 236                         if ( $this->timestamp === null ) {
 237                                 // This can only happen if $force is enabled.
 238                                 $notificationTimestamp = null;
 239                         } else {
 240                                 // Oldid given and isn't the latest; update the timestamp.
 241                                 // This will result in no further notification emails being sent!
 242                                 $dbr = wfGetDB( DB_SLAVE );
 243                                 $notificationTimestamp = $dbr->selectField(
 244                                         'revision', 'rev_timestamp',
 245                                         array( 'rev_page' => $title->getArticleID(), 'rev_id' => $oldid )
 246                                 );
 247                                 // We need to go one second to the future because of various strict comparisons
 248                                 // throughout the codebase
 249                                 $ts = new MWTimestamp( $notificationTimestamp );
 250                                 $ts->timestamp->add( new DateInterval( 'PT1S' ) );
 251                                 $notificationTimestamp = $ts->getTimestamp( TS_MW );
 252
 253                                 if ( $notificationTimestamp < $this->timestamp ) {
 254                                         if ( $force != 'force' ) {
 255                                                 return;
 256                                         } else {
 257                                                 // This is a little silly…
 258                                                 $notificationTimestamp = $this->timestamp;
 259                                         }
 260                                 }
 261                         }
 262                 }
 263
 264                 // If the page is watched by the user (or may be watched), update the timestamp on any
 265                 // any matching rows
 266                 $dbw = wfGetDB( DB_MASTER );
 267                 $dbw->update( 'watchlist', array( 'wl_notificationtimestamp' => $notificationTimestamp ),
 268                         $this->dbCond(), __METHOD__ );
 269                 $this->timestamp = null;
 270         }
 271
 272         /**
 273          * Given a title and user (assumes the object is setup), add the watch to the database.
 274          * @return bool
 275          */
 276         public function addWatch() {
 277                 wfProfileIn( __METHOD__ );
 278
 279                 // Only loggedin user can have a watchlist
 280                 if ( wfReadOnly() || $this->mUser->isAnon() || !$this->isAllowed( 'editmywatchlist' ) ) {
 281                         wfProfileOut( __METHOD__ );
 282                         return false;
 283                 }
 284
 285                 // Use INSERT IGNORE to avoid overwriting the notification timestamp
 286                 // if there's already an entry for this page
 287                 $dbw = wfGetDB( DB_MASTER );
 288                 $dbw->insert( 'watchlist',
 289                         array(
 290                                 'wl_user' => $this->getUserId(),
 291                                 'wl_namespace' => MWNamespace::getSubject( $this->getTitleNs() ),
 292                                 'wl_title' => $this->getTitleDBkey(),
 293                                 'wl_notificationtimestamp' => null
 294                         ), __METHOD__, 'IGNORE' );
 295
 296                 // Every single watched page needs now to be listed in watchlist;
 297                 // namespace:page and namespace_talk:page need separate entries:
 298                 $dbw->insert( 'watchlist',
 299                         array(
 300                                 'wl_user' => $this->getUserId(),
 301                                 'wl_namespace' => MWNamespace::getTalk( $this->getTitleNs() ),
 302                                 'wl_title' => $this->getTitleDBkey(),
 303                                 'wl_notificationtimestamp' => null
 304                         ), __METHOD__, 'IGNORE' );
 305
 306                 $this->watched = true;
 307
 308                 wfProfileOut( __METHOD__ );
 309                 return true;
 310         }
 311
 312         /**
 313          * Same as addWatch, only the opposite.
 314          * @return bool
 315          */
 316         public function removeWatch() {
 317                 wfProfileIn( __METHOD__ );
 318
 319                 // Only loggedin user can have a watchlist
 320                 if ( wfReadOnly() || $this->mUser->isAnon() || !$this->isAllowed( 'editmywatchlist' ) ) {
 321                         wfProfileOut( __METHOD__ );
 322                         return false;
 323                 }
 324
 325                 $success = false;
 326                 $dbw = wfGetDB( DB_MASTER );
 327                 $dbw->delete( 'watchlist',
 328                         array(
 329                                 'wl_user' => $this->getUserId(),
 330                                 'wl_namespace' => MWNamespace::getSubject( $this->getTitleNs() ),
 331                                 'wl_title' => $this->getTitleDBkey(),
 332                         ), __METHOD__
 333                 );
 334                 if ( $dbw->affectedRows() ) {
 335                         $success = true;
 336                 }
 337
 338                 # the following code compensates the new behavior, introduced by the
 339                 # enotif patch, that every single watched page needs now to be listed
 340                 # in watchlist namespace:page and namespace_talk:page had separate
 341                 # entries: clear them
 342                 $dbw->delete( 'watchlist',
 343                         array(
 344                                 'wl_user' => $this->getUserId(),
 345                                 'wl_namespace' => MWNamespace::getTalk( $this->getTitleNs() ),
 346                                 'wl_title' => $this->getTitleDBkey(),
 347                         ), __METHOD__
 348                 );
 349
 350                 if ( $dbw->affectedRows() ) {
 351                         $success = true;
 352                 }
 353
 354                 $this->watched = false;
 355
 356                 wfProfileOut( __METHOD__ );
 357                 return $success;
 358         }
 359
 360         /**
 361          * Check if the given title already is watched by the user, and if so
 362          * add watches on a new title. To be used for page renames and such.
 363          *
 364          * @param Title $ot Page title to duplicate entries from, if present
 365          * @param Title $nt Page title to add watches on
 366          */
 367         public static function duplicateEntries( $ot, $nt ) {
 368                 WatchedItem::doDuplicateEntries( $ot->getSubjectPage(), $nt->getSubjectPage() );
 369                 WatchedItem::doDuplicateEntries( $ot->getTalkPage(), $nt->getTalkPage() );
 370         }
 371
 372         /**
 373          * Handle duplicate entries. Backend for duplicateEntries().
 374          *
 375          * @param Title $ot
 376          * @param Title $nt
 377          *
 378          * @return bool
 379          */
 380         private static function doDuplicateEntries( $ot, $nt ) {
 381                 $oldnamespace = $ot->getNamespace();
 382                 $newnamespace = $nt->getNamespace();
 383                 $oldtitle = $ot->getDBkey();
 384                 $newtitle = $nt->getDBkey();
 385
 386                 $dbw = wfGetDB( DB_MASTER );
 387                 $res = $dbw->select( 'watchlist', 'wl_user',
 388                         array( 'wl_namespace' => $oldnamespace, 'wl_title' => $oldtitle ),
 389                         __METHOD__, 'FOR UPDATE'
 390                 );
 391                 # Construct array to replace into the watchlist
 392                 $values = array();
 393                 foreach ( $res as $s ) {
 394                         $values[] = array(
 395                                 'wl_user' => $s->wl_user,
 396                                 'wl_namespace' => $newnamespace,
 397                                 'wl_title' => $newtitle
 398                         );
 399                 }
 400
 401                 if ( empty( $values ) ) {
 402                         // Nothing to do
 403                         return true;
 404                 }
 405
 406                 # Perform replace
 407                 # Note that multi-row replace is very efficient for MySQL but may be inefficient for
 408                 # some other DBMSes, mostly due to poor simulation by us
 409                 $dbw->replace(
 410                         'watchlist',
 411                         array( array( 'wl_user', 'wl_namespace', 'wl_title' ) ),
 412                         $values,
 413                         __METHOD__
 414                 );
 415
 416                 return true;
 417         }
 418 }