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