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