includes/actions/HistoryAction.php

   1 <?php
   2 /**
   3  * Page history
   4  *
   5  * Split off from Article.php and Skin.php, 2003-12-22
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License as published by
   9  * the Free Software Foundation; either version 2 of the License, or
  10  * (at your option) any later version.
  11  *
  12  * This program is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  15  * GNU General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU General Public License along
  18  * with this program; if not, write to the Free Software Foundation, Inc.,
  19  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  20  * http://www.gnu.org/copyleft/gpl.html
  21  *
  22  * @file
  23  */
  24
  25 /**
  26  * This class handles printing the history page for an article.  In order to
  27  * be efficient, it uses timestamps rather than offsets for paging, to avoid
  28  * costly LIMIT,offset queries.
  29  *
  30  * Construct it by passing in an Article, and call $h->history() to print the
  31  * history.
  32  *
  33  */
  34 class HistoryAction extends FormlessAction {
  35         const DIR_PREV = 0;
  36         const DIR_NEXT = 1;
  37
  38         public function getName() {
  39                 return 'history';
  40         }
  41
  42         public function requiresWrite() {
  43                 return false;
  44         }
  45
  46         public function requiresUnblock() {
  47                 return false;
  48         }
  49
  50         protected function getPageTitle() {
  51                 return $this->msg( 'history-title', $this->getTitle()->getPrefixedText() )->text();
  52         }
  53
  54         protected function getDescription() {
  55                 // Creation of a subtitle link pointing to [[Special:Log]]
  56                 return Linker::linkKnown(
  57                         SpecialPage::getTitleFor( 'Log' ),
  58                         $this->msg( 'viewpagelogs' )->escaped(),
  59                         array(),
  60                         array( 'page' => $this->getTitle()->getPrefixedText() )
  61                 );
  62         }
  63
  64         /**
  65          * Get the Article object we are working on.
  66          * @return Page
  67          */
  68         public function getArticle() {
  69                 return $this->page;
  70         }
  71
  72         /**
  73          * As we use the same small set of messages in various methods and that
  74          * they are called often, we call them once and save them in $this->message
  75          */
  76         private function preCacheMessages() {
  77                 // Precache various messages
  78                 if ( !isset( $this->message ) ) {
  79                         $msgs = array( 'cur', 'last', 'pipe-separator' );
  80                         foreach ( $msgs as $msg ) {
  81                                 $this->message[$msg] = $this->msg( $msg )->escaped();
  82                         }
  83                 }
  84         }
  85
  86         /**
  87          * Print the history page for an article.
  88          */
  89         function onView() {
  90                 global $wgScript, $wgUseFileCache;
  91
  92                 $out = $this->getOutput();
  93                 $request = $this->getRequest();
  94
  95                 /**
  96                  * Allow client caching.
  97                  */
  98                 if ( $out->checkLastModified( $this->page->getTouched() ) ) {
  99                         return; // Client cache fresh and headers sent, nothing more to do.
 100                 }
 101
 102                 wfProfileIn( __METHOD__ );
 103
 104                 $this->preCacheMessages();
 105
 106                 # Fill in the file cache if not set already
 107                 if ( $wgUseFileCache && HTMLFileCache::useFileCache( $this->getContext() ) ) {
 108                         $cache = HTMLFileCache::newFromTitle( $this->getTitle(), 'history' );
 109                         if ( !$cache->isCacheGood( /* Assume up to date */ ) ) {
 110                                 ob_start( array( &$cache, 'saveToFileCache' ) );
 111                         }
 112                 }
 113
 114                 // Setup page variables.
 115                 $out->setFeedAppendQuery( 'action=history' );
 116                 $out->addModules( array( 'mediawiki.legacy.history', 'mediawiki.action.history' ) );
 117
 118                 // Handle atom/RSS feeds.
 119                 $feedType = $request->getVal( 'feed' );
 120                 if ( $feedType ) {
 121                         $this->feed( $feedType );
 122                         wfProfileOut( __METHOD__ );
 123                         return;
 124                 }
 125
 126                 // Fail nicely if article doesn't exist.
 127                 if ( !$this->page->exists() ) {
 128                         $out->addWikiMsg( 'nohistory' );
 129                         # show deletion/move log if there is an entry
 130                         LogEventsList::showLogExtract(
 131                                 $out,
 132                                 array( 'delete', 'move' ),
 133                                 $this->getTitle(),
 134                                 '',
 135                                 array(  'lim' => 10,
 136                                         'conds' => array( "log_action != 'revision'" ),
 137                                         'showIfEmpty' => false,
 138                                         'msgKey' => array( 'moveddeleted-notice' )
 139                                 )
 140                         );
 141                         wfProfileOut( __METHOD__ );
 142                         return;
 143                 }
 144
 145                 /**
 146                  * Add date selector to quickly get to a certain time
 147                  */
 148                 $year        = $request->getInt( 'year' );
 149                 $month       = $request->getInt( 'month' );
 150                 $tagFilter   = $request->getVal( 'tagfilter' );
 151                 $tagSelector = ChangeTags::buildTagFilterSelector( $tagFilter );
 152
 153                 /**
 154                  * Option to show only revisions that have been (partially) hidden via RevisionDelete
 155                  */
 156                 if ( $request->getBool( 'deleted' ) ) {
 157                         $conds = array( "rev_deleted != '0'" );
 158                 } else {
 159                         $conds = array();
 160                 }
 161                 $checkDeleted = Xml::checkLabel( $this->msg( 'history-show-deleted' )->text(),
 162                         'deleted', 'mw-show-deleted-only', $request->getBool( 'deleted' ) ) . "\n";
 163
 164                 // Add the general form
 165                 $action = htmlspecialchars( $wgScript );
 166                 $out->addHTML(
 167                         "<form action=\"$action\" method=\"get\" id=\"mw-history-searchform\">" .
 168                         Xml::fieldset(
 169                                 $this->msg( 'history-fieldset-title' )->text(),
 170                                 false,
 171                                 array( 'id' => 'mw-history-search' )
 172                         ) .
 173                         Html::hidden( 'title', $this->getTitle()->getPrefixedDBKey() ) . "\n" .
 174                         Html::hidden( 'action', 'history' ) . "\n" .
 175                         Xml::dateMenu( $year, $month ) . '&#160;' .
 176                         ( $tagSelector ? ( implode( '&#160;', $tagSelector ) . '&#160;' ) : '' ) .
 177                         $checkDeleted .
 178                         Xml::submitButton( $this->msg( 'allpagessubmit' )->text() ) . "\n" .
 179                         '</fieldset></form>'
 180                 );
 181
 182                 wfRunHooks( 'PageHistoryBeforeList', array( &$this->page ) );
 183
 184                 // Create and output the list.
 185                 $pager = new HistoryPager( $this, $year, $month, $tagFilter, $conds );
 186                 $out->addHTML(
 187                         $pager->getNavigationBar() .
 188                         $pager->getBody() .
 189                         $pager->getNavigationBar()
 190                 );
 191                 $out->preventClickjacking( $pager->getPreventClickjacking() );
 192
 193                 wfProfileOut( __METHOD__ );
 194         }
 195
 196         /**
 197          * Fetch an array of revisions, specified by a given limit, offset and
 198          * direction. This is now only used by the feeds. It was previously
 199          * used by the main UI but that's now handled by the pager.
 200          *
 201          * @param $limit Integer: the limit number of revisions to get
 202          * @param $offset Integer
 203          * @param $direction Integer: either HistoryPage::DIR_PREV or HistoryPage::DIR_NEXT
 204          * @return ResultWrapper
 205          */
 206         function fetchRevisions( $limit, $offset, $direction ) {
 207                 $dbr = wfGetDB( DB_SLAVE );
 208
 209                 if ( $direction == HistoryPage::DIR_PREV ) {
 210                         list( $dirs, $oper ) = array( "ASC", ">=" );
 211                 } else { /* $direction == HistoryPage::DIR_NEXT */
 212                         list( $dirs, $oper ) = array( "DESC", "<=" );
 213                 }
 214
 215                 if ( $offset ) {
 216                         $offsets = array( "rev_timestamp $oper '$offset'" );
 217                 } else {
 218                         $offsets = array();
 219                 }
 220
 221                 $page_id = $this->page->getId();
 222
 223                 return $dbr->select( 'revision',
 224                         Revision::selectFields(),
 225                         array_merge( array( "rev_page=$page_id" ), $offsets ),
 226                         __METHOD__,
 227                         array( 'ORDER BY' => "rev_timestamp $dirs",
 228                                 'USE INDEX' => 'page_timestamp', 'LIMIT' => $limit )
 229                 );
 230         }
 231
 232         /**
 233          * Output a subscription feed listing recent edits to this page.
 234          *
 235          * @param $type String: feed type
 236          */
 237         function feed( $type ) {
 238                 global $wgFeedClasses, $wgFeedLimit;
 239                 if ( !FeedUtils::checkFeedOutput( $type ) ) {
 240                         return;
 241                 }
 242                 $request = $this->getRequest();
 243
 244                 $feed = new $wgFeedClasses[$type](
 245                         $this->getTitle()->getPrefixedText() . ' - ' .
 246                         wfMsgForContent( 'history-feed-title' ),
 247                         wfMsgForContent( 'history-feed-description' ),
 248                         $this->getTitle()->getFullUrl( 'action=history' )
 249                 );
 250
 251                 // Get a limit on number of feed entries. Provide a sane default
 252                 // of 10 if none is defined (but limit to $wgFeedLimit max)
 253                 $limit = $request->getInt( 'limit', 10 );
 254                 if ( $limit > $wgFeedLimit || $limit < 1 ) {
 255                         $limit = 10;
 256                 }
 257                 $items = $this->fetchRevisions( $limit, 0, HistoryPage::DIR_NEXT );
 258
 259                 // Generate feed elements enclosed between header and footer.
 260                 $feed->outHeader();
 261                 if ( $items->numRows() ) {
 262                         foreach ( $items as $row ) {
 263                                 $feed->outItem( $this->feedItem( $row ) );
 264                         }
 265                 } else {
 266                         $feed->outItem( $this->feedEmpty() );
 267                 }
 268                 $feed->outFooter();
 269         }
 270
 271         function feedEmpty() {
 272                 return new FeedItem(
 273                         wfMsgForContent( 'nohistory' ),
 274                         $this->getOutput()->parse( wfMsgForContent( 'history-feed-empty' ) ),
 275                         $this->getTitle()->getFullUrl(),
 276                         wfTimestamp( TS_MW ),
 277                         '',
 278                         $this->getTitle()->getTalkPage()->getFullUrl()
 279                 );
 280         }
 281
 282         /**
 283          * Generate a FeedItem object from a given revision table row
 284          * Borrows Recent Changes' feed generation functions for formatting;
 285          * includes a diff to the previous revision (if any).
 286          *
 287          * @param $row Object: database row
 288          * @return FeedItem
 289          */
 290         function feedItem( $row ) {
 291                 $rev = new Revision( $row );
 292                 $rev->setTitle( $this->getTitle() );
 293                 $text = FeedUtils::formatDiffRow(
 294                         $this->getTitle(),
 295                         $this->getTitle()->getPreviousRevisionID( $rev->getId() ),
 296                         $rev->getId(),
 297                         $rev->getTimestamp(),
 298                         $rev->getComment()
 299                 );
 300                 if ( $rev->getComment() == '' ) {
 301                         global $wgContLang;
 302                         $title = wfMsgForContent( 'history-feed-item-nocomment',
 303                                 $rev->getUserText(),
 304                                 $wgContLang->timeanddate( $rev->getTimestamp() ),
 305                                 $wgContLang->date( $rev->getTimestamp() ),
 306                                 $wgContLang->time( $rev->getTimestamp() )
 307                         );
 308                 } else {
 309                         $title = $rev->getUserText() .
 310                         wfMsgForContent( 'colon-separator' ) .
 311                         FeedItem::stripComment( $rev->getComment() );
 312                 }
 313                 return new FeedItem(
 314                         $title,
 315                         $text,
 316                         $this->getTitle()->getFullUrl( 'diff=' . $rev->getId() . '&oldid=prev' ),
 317                         $rev->getTimestamp(),
 318                         $rev->getUserText(),
 319                         $this->getTitle()->getTalkPage()->getFullUrl()
 320                 );
 321         }
 322 }
 323
 324 /**
 325  * @ingroup Pager
 326  */
 327 class HistoryPager extends ReverseChronologicalPager {
 328         public $lastRow = false, $counter, $historyPage, $buttons, $conds;
 329         protected $oldIdChecked;
 330         protected $preventClickjacking = false;
 331         /**
 332          * @var array
 333          */
 334         protected $parentLens;
 335
 336         function __construct( $historyPage, $year = '', $month = '', $tagFilter = '', $conds = array() ) {
 337                 parent::__construct( $historyPage->getContext() );
 338                 $this->historyPage = $historyPage;
 339                 $this->tagFilter = $tagFilter;
 340                 $this->getDateCond( $year, $month );
 341                 $this->conds = $conds;
 342         }
 343
 344         // For hook compatibility...
 345         function getArticle() {
 346                 return $this->historyPage->getArticle();
 347         }
 348
 349         function getSqlComment() {
 350                 if ( $this->conds ) {
 351                         return 'history page filtered'; // potentially slow, see CR r58153
 352                 } else {
 353                         return 'history page unfiltered';
 354                 }
 355         }
 356
 357         function getQueryInfo() {
 358                 $queryInfo = array(
 359                         'tables'  => array( 'revision', 'user' ),
 360                         'fields'  => array_merge( Revision::selectFields(), Revision::selectUserFields() ),
 361                         'conds'   => array_merge(
 362                                 array( 'rev_page' => $this->getWikiPage()->getId() ),
 363                                 $this->conds ),
 364                         'options' => array( 'USE INDEX' => array( 'revision' => 'page_timestamp' ) ),
 365                         'join_conds' => array(
 366                                 'user'        => Revision::userJoinCond(),
 367                                 'tag_summary' => array( 'LEFT JOIN', 'ts_rev_id=rev_id' ) ),
 368                 );
 369                 ChangeTags::modifyDisplayQuery(
 370                         $queryInfo['tables'],
 371                         $queryInfo['fields'],
 372                         $queryInfo['conds'],
 373                         $queryInfo['join_conds'],
 374                         $queryInfo['options'],
 375                         $this->tagFilter
 376                 );
 377                 wfRunHooks( 'PageHistoryPager::getQueryInfo', array( &$this, &$queryInfo ) );
 378                 return $queryInfo;
 379         }
 380
 381         function getIndexField() {
 382                 return 'rev_timestamp';
 383         }
 384
 385         function formatRow( $row ) {
 386                 if ( $this->lastRow ) {
 387                         $latest = ( $this->counter == 1 && $this->mIsFirst );
 388                         $firstInList = $this->counter == 1;
 389                         $this->counter++;
 390                         $s = $this->historyLine( $this->lastRow, $row,
 391                                 $this->getTitle()->getNotificationTimestamp( $this->getUser() ), $latest, $firstInList );
 392                 } else {
 393                         $s = '';
 394                 }
 395                 $this->lastRow = $row;
 396                 return $s;
 397         }
 398
 399         function doBatchLookups() {
 400                 # Do a link batch query
 401                 $this->mResult->seek( 0 );
 402                 $batch = new LinkBatch();
 403                 $revIds = array();
 404                 foreach ( $this->mResult as $row ) {
 405                         if( $row->rev_parent_id ) {
 406                                 $revIds[] = $row->rev_parent_id;
 407                         }
 408                         if( !is_null( $row->user_name ) ) {
 409                                 $batch->add( NS_USER, $row->user_name );
 410                                 $batch->add( NS_USER_TALK, $row->user_name );
 411                         } else { # for anons or usernames of imported revisions
 412                                 $batch->add( NS_USER, $row->rev_user_text );
 413                                 $batch->add( NS_USER_TALK, $row->rev_user_text );
 414                         }
 415                 }
 416                 $this->parentLens = $this->getParentLengths( $revIds );
 417                 $batch->execute();
 418                 $this->mResult->seek( 0 );
 419         }
 420
 421         /**
 422          * Do a batched query to get the parent revision lengths
 423          * @param $revIds array
 424          * @return array
 425          * @TODO: stolen from Contributions, refactor
 426          */
 427         private function getParentLengths( array $revIds ) {
 428                 $revLens = array();
 429                 if ( !$revIds ) {
 430                         return $revLens; // empty
 431                 }
 432                 wfProfileIn( __METHOD__ );
 433                 $res = $this->mDb->select( 'revision',
 434                         array( 'rev_id', 'rev_len' ),
 435                         array( 'rev_id' => $revIds ),
 436                         __METHOD__ );
 437                 foreach ( $res as $row ) {
 438                         $revLens[$row->rev_id] = $row->rev_len;
 439                 }
 440                 wfProfileOut( __METHOD__ );
 441                 return $revLens;
 442         }
 443
 444         /**
 445          * Creates begin of history list with a submit button
 446          *
 447          * @return string HTML output
 448          */
 449         function getStartBody() {
 450                 global $wgScript;
 451                 $this->lastRow = false;
 452                 $this->counter = 1;
 453                 $this->oldIdChecked = 0;
 454
 455                 $this->getOutput()->wrapWikiMsg( "<div class='mw-history-legend'>\n$1\n</div>", 'histlegend' );
 456                 $s = Html::openElement( 'form', array( 'action' => $wgScript,
 457                         'id' => 'mw-history-compare' ) ) . "\n";
 458                 $s .= Html::hidden( 'title', $this->getTitle()->getPrefixedDbKey() ) . "\n";
 459                 $s .= Html::hidden( 'action', 'historysubmit' ) . "\n";
 460
 461                 // Button container stored in $this->buttons for re-use in getEndBody()
 462                 $this->buttons = '<div>';
 463                 $this->buttons .= $this->submitButton( $this->msg( 'compareselectedversions' )->text(),
 464                         array( 'class' => 'historysubmit mw-history-compareselectedversions-button' )
 465                                 + Linker::tooltipAndAccesskeyAttribs( 'compareselectedversions' )
 466                 ) . "\n";
 467
 468                 if ( $this->getUser()->isAllowed( 'deleterevision' ) ) {
 469                         $this->buttons .= $this->getRevisionButton( 'revisiondelete', 'showhideselectedversions' );
 470                 }
 471                 $this->buttons .= '</div>';
 472
 473                 $s .= $this->buttons;
 474                 $s .= '<ul id="pagehistory">' . "\n";
 475                 return $s;
 476         }
 477
 478         private function getRevisionButton( $name, $msg ) {
 479                 $this->preventClickjacking();
 480                 # Note bug #20966, <button> is non-standard in IE<8
 481                 $element = Html::element( 'button',
 482                         array(
 483                                 'type' => 'submit',
 484                                 'name' => $name,
 485                                 'value' => '1',
 486                                 'class' => "historysubmit mw-history-$name-button",
 487                         ),
 488                         $this->msg( $msg )->text()
 489                 ) . "\n";
 490                 return $element;
 491         }
 492
 493         function getEndBody() {
 494                 if ( $this->lastRow ) {
 495                         $latest = $this->counter == 1 && $this->mIsFirst;
 496                         $firstInList = $this->counter == 1;
 497                         if ( $this->mIsBackwards ) {
 498                                 # Next row is unknown, but for UI reasons, probably exists if an offset has been specified
 499                                 if ( $this->mOffset == '' ) {
 500                                         $next = null;
 501                                 } else {
 502                                         $next = 'unknown';
 503                                 }
 504                         } else {
 505                                 # The next row is the past-the-end row
 506                                 $next = $this->mPastTheEndRow;
 507                         }
 508                         $this->counter++;
 509                         $s = $this->historyLine( $this->lastRow, $next,
 510                                 $this->getTitle()->getNotificationTimestamp( $this->getUser() ), $latest, $firstInList );
 511                 } else {
 512                         $s = '';
 513                 }
 514                 $s .= "</ul>\n";
 515                 # Add second buttons only if there is more than one rev
 516                 if ( $this->getNumRows() > 2 ) {
 517                         $s .= $this->buttons;
 518                 }
 519                 $s .= '</form>';
 520                 return $s;
 521         }
 522
 523         /**
 524          * Creates a submit button
 525          *
 526          * @param $message String: text of the submit button, will be escaped
 527          * @param $attributes Array: attributes
 528          * @return String: HTML output for the submit button
 529          */
 530         function submitButton( $message, $attributes = array() ) {
 531                 # Disable submit button if history has 1 revision only
 532                 if ( $this->getNumRows() > 1 ) {
 533                         return Xml::submitButton( $message , $attributes );
 534                 } else {
 535                         return '';
 536                 }
 537         }
 538
 539         /**
 540          * Returns a row from the history printout.
 541          *
 542          * @todo document some more, and maybe clean up the code (some params redundant?)
 543          *
 544          * @param $row Object: the database row corresponding to the previous line.
 545          * @param $next Mixed: the database row corresponding to the next line. (chronologically previous)
 546          * @param $notificationtimestamp
 547          * @param $latest Boolean: whether this row corresponds to the page's latest revision.
 548          * @param $firstInList Boolean: whether this row corresponds to the first displayed on this history page.
 549          * @return String: HTML output for the row
 550          */
 551         function historyLine( $row, $next, $notificationtimestamp = false,
 552                 $latest = false, $firstInList = false )
 553         {
 554                 $rev = new Revision( $row );
 555                 $rev->setTitle( $this->getTitle() );
 556
 557                 if ( is_object( $next ) ) {
 558                         $prevRev = new Revision( $next );
 559                         $prevRev->setTitle( $this->getTitle() );
 560                 } else {
 561                         $prevRev = null;
 562                 }
 563
 564                 $curlink = $this->curLink( $rev, $latest );
 565                 $lastlink = $this->lastLink( $rev, $next );
 566                 $diffButtons = $this->diffButtons( $rev, $firstInList );
 567                 $histLinks = Html::rawElement(
 568                                 'span',
 569                                 array( 'class' => 'mw-history-histlinks' ),
 570                                 $this->msg( 'parentheses' )->rawParams( $curlink . $this->historyPage->message['pipe-separator'] . $lastlink )->escaped()
 571                 );
 572                 $s = $histLinks . $diffButtons;
 573
 574                 $link = $this->revLink( $rev );
 575                 $classes = array();
 576
 577                 $del = '';
 578                 $user = $this->getUser();
 579                 // Show checkboxes for each revision
 580                 if ( $user->isAllowed( 'deleterevision' ) ) {
 581                         $this->preventClickjacking();
 582                         // If revision was hidden from sysops, disable the checkbox
 583                         if ( !$rev->userCan( Revision::DELETED_RESTRICTED, $user ) ) {
 584                                 $del = Xml::check( 'deleterevisions', false, array( 'disabled' => 'disabled' ) );
 585                         // Otherwise, enable the checkbox...
 586                         } else {
 587                                 $del = Xml::check( 'showhiderevisions', false,
 588                                         array( 'name' => 'ids[' . $rev->getId() . ']' ) );
 589                         }
 590                 // User can only view deleted revisions...
 591                 } elseif ( $rev->getVisibility() && $user->isAllowed( 'deletedhistory' ) ) {
 592                         // If revision was hidden from sysops, disable the link
 593                         if ( !$rev->userCan( Revision::DELETED_RESTRICTED, $user ) ) {
 594                                 $cdel = Linker::revDeleteLinkDisabled( false );
 595                         // Otherwise, show the link...
 596                         } else {
 597                                 $query = array( 'type' => 'revision',
 598                                         'target' => $this->getTitle()->getPrefixedDbkey(), 'ids' => $rev->getId() );
 599                                 $del .= Linker::revDeleteLink( $query,
 600                                         $rev->isDeleted( Revision::DELETED_RESTRICTED ), false );
 601                         }
 602                 }
 603                 if ( $del ) {
 604                         $s .= " $del ";
 605                 }
 606
 607                 $lang = $this->getLanguage();
 608                 $dirmark = $lang->getDirMark();
 609
 610                 $s .= " $link";
 611                 $s .= $dirmark;
 612                 $s .= " <span class='history-user'>" .
 613                         Linker::revUserTools( $rev, true ) . "</span>";
 614                 $s .= $dirmark;
 615
 616                 if ( $rev->isMinor() ) {
 617                         $s .= ' ' . ChangesList::flag( 'minor' );
 618                 }
 619
 620                 # Size is always public data
 621                 $prevSize = isset( $this->parentLens[$row->rev_parent_id] )
 622                         ? $this->parentLens[$row->rev_parent_id]
 623                         : 0;
 624                 $sDiff = ChangesList::showCharacterDifference( $prevSize, $rev->getSize() );
 625                 $fSize = Linker::formatRevisionSize($rev->getSize());
 626                 $s .= " . . $fSize $sDiff";
 627
 628                 # Text following the character difference is added just before running hooks
 629                 $s2 = Linker::revComment( $rev, false, true );
 630
 631                 if ( $notificationtimestamp && ( $row->rev_timestamp >= $notificationtimestamp ) ) {
 632                         $s2 .= ' <span class="updatedmarker">' .  $this->msg( 'updatedmarker' )->escaped() . '</span>';
 633                 }
 634
 635                 $tools = array();
 636
 637                 # Rollback and undo links
 638                 if ( $prevRev &&
 639                         !count( $this->getTitle()->getUserPermissionsErrors( 'edit', $this->getUser() ) ) )
 640                 {
 641                         if ( $latest && !count( $this->getTitle()->getUserPermissionsErrors( 'rollback', $this->getUser() ) ) ) {
 642                                 $this->preventClickjacking();
 643                                 $tools[] = '<span class="mw-rollback-link">' .
 644                                         Linker::buildRollbackLink( $rev ) . '</span>';
 645                         }
 646
 647                         if ( !$rev->isDeleted( Revision::DELETED_TEXT )
 648                                 && !$prevRev->isDeleted( Revision::DELETED_TEXT ) )
 649                         {
 650                                 # Create undo tooltip for the first (=latest) line only
 651                                 $undoTooltip = $latest
 652                                         ? array( 'title' => $this->msg( 'tooltip-undo' )->text() )
 653                                         : array();
 654                                 $undolink = Linker::linkKnown(
 655                                         $this->getTitle(),
 656                                         $this->msg( 'editundo' )->escaped(),
 657                                         $undoTooltip,
 658                                         array(
 659                                                 'action'    => 'edit',
 660                                                 'undoafter' => $prevRev->getId(),
 661                                                 'undo'      => $rev->getId()
 662                                         )
 663                                 );
 664                                 $tools[] = "<span class=\"mw-history-undo\">{$undolink}</span>";
 665                         }
 666                 }
 667
 668                 if ( $tools ) {
 669                         $s2 .= ' '. $this->msg( 'parentheses' )->rawParams( $lang->pipeList( $tools ) )->escaped();
 670                 }
 671
 672                 # Tags
 673                 list( $tagSummary, $newClasses ) = ChangeTags::formatSummaryRow( $row->ts_tags, 'history' );
 674                 $classes = array_merge( $classes, $newClasses );
 675                 if ( $tagSummary !== '' ) {
 676                         $s2 .= " $tagSummary";
 677                 }
 678
 679                 # Include separator between character difference and following text
 680                 if ( $s2 !== '' ) {
 681                         $s .= " . . $s2";
 682                 }
 683
 684                 wfRunHooks( 'PageHistoryLineEnding', array( $this, &$row , &$s, &$classes ) );
 685
 686                 $attribs = array();
 687                 if ( $classes ) {
 688                         $attribs['class'] = implode( ' ', $classes );
 689                 }
 690
 691                 return Xml::tags( 'li', $attribs, $s ) . "\n";
 692         }
 693
 694         /**
 695          * Create a link to view this revision of the page
 696          *
 697          * @param $rev Revision
 698          * @return String
 699          */
 700         function revLink( $rev ) {
 701                 $date = $this->getLanguage()->userTimeAndDate( $rev->getTimestamp(), $this->getUser() );
 702                 $date = htmlspecialchars( $date );
 703                 if ( $rev->userCan( Revision::DELETED_TEXT, $this->getUser() ) ) {
 704                         $link = Linker::linkKnown(
 705                                 $this->getTitle(),
 706                                 $date,
 707                                 array(),
 708                                 array( 'oldid' => $rev->getId() )
 709                         );
 710                 } else {
 711                         $link = $date;
 712                 }
 713                 if ( $rev->isDeleted( Revision::DELETED_TEXT ) ) {
 714                         $link = "<span class=\"history-deleted\">$link</span>";
 715                 }
 716                 return $link;
 717         }
 718
 719         /**
 720          * Create a diff-to-current link for this revision for this page
 721          *
 722          * @param $rev Revision
 723          * @param $latest Boolean: this is the latest revision of the page?
 724          * @return String
 725          */
 726         function curLink( $rev, $latest ) {
 727                 $cur = $this->historyPage->message['cur'];
 728                 if ( $latest || !$rev->userCan( Revision::DELETED_TEXT, $this->getUser() ) ) {
 729                         return $cur;
 730                 } else {
 731                         return Linker::linkKnown(
 732                                 $this->getTitle(),
 733                                 $cur,
 734                                 array(),
 735                                 array(
 736                                         'diff' => $this->getWikiPage()->getLatest(),
 737                                         'oldid' => $rev->getId()
 738                                 )
 739                         );
 740                 }
 741         }
 742
 743         /**
 744          * Create a diff-to-previous link for this revision for this page.
 745          *
 746          * @param $prevRev Revision: the previous revision
 747          * @param $next Mixed: the newer revision
 748          * @return String
 749          */
 750         function lastLink( $prevRev, $next ) {
 751                 $last = $this->historyPage->message['last'];
 752                 # $next may either be a Row, null, or "unkown"
 753                 $nextRev = is_object( $next ) ? new Revision( $next ) : $next;
 754                 if ( is_null( $next ) ) {
 755                         # Probably no next row
 756                         return $last;
 757                 } elseif ( $next === 'unknown' ) {
 758                         # Next row probably exists but is unknown, use an oldid=prev link
 759                         return Linker::linkKnown(
 760                                 $this->getTitle(),
 761                                 $last,
 762                                 array(),
 763                                 array(
 764                                         'diff' => $prevRev->getId(),
 765                                         'oldid' => 'prev'
 766                                 )
 767                         );
 768                 } elseif ( !$prevRev->userCan( Revision::DELETED_TEXT, $this->getUser() )
 769                         || !$nextRev->userCan( Revision::DELETED_TEXT, $this->getUser() ) )
 770                 {
 771                         return $last;
 772                 } else {
 773                         return Linker::linkKnown(
 774                                 $this->getTitle(),
 775                                 $last,
 776                                 array(),
 777                                 array(
 778                                         'diff' => $prevRev->getId(),
 779                                         'oldid' => $next->rev_id
 780                                 )
 781                         );
 782                 }
 783         }
 784
 785         /**
 786          * Create radio buttons for page history
 787          *
 788          * @param $rev Revision object
 789          * @param $firstInList Boolean: is this version the first one?
 790          *
 791          * @return String: HTML output for the radio buttons
 792          */
 793         function diffButtons( $rev, $firstInList ) {
 794                 if ( $this->getNumRows() > 1 ) {
 795                         $id = $rev->getId();
 796                         $radio = array( 'type'  => 'radio', 'value' => $id );
 797                         /** @todo: move title texts to javascript */
 798                         if ( $firstInList ) {
 799                                 $first = Xml::element( 'input',
 800                                         array_merge( $radio, array(
 801                                                 'style' => 'visibility:hidden',
 802                                                 'name'  => 'oldid',
 803                                                 'id' => 'mw-oldid-null' ) )
 804                                 );
 805                                 $checkmark = array( 'checked' => 'checked' );
 806                         } else {
 807                                 # Check visibility of old revisions
 808                                 if ( !$rev->userCan( Revision::DELETED_TEXT, $this->getUser() ) ) {
 809                                         $radio['disabled'] = 'disabled';
 810                                         $checkmark = array(); // We will check the next possible one
 811                                 } elseif ( !$this->oldIdChecked ) {
 812                                         $checkmark = array( 'checked' => 'checked' );
 813                                         $this->oldIdChecked = $id;
 814                                 } else {
 815                                         $checkmark = array();
 816                                 }
 817                                 $first = Xml::element( 'input',
 818                                         array_merge( $radio, $checkmark, array(
 819                                                 'name'  => 'oldid',
 820                                                 'id' => "mw-oldid-$id" ) ) );
 821                                 $checkmark = array();
 822                         }
 823                         $second = Xml::element( 'input',
 824                                 array_merge( $radio, $checkmark, array(
 825                                         'name'  => 'diff',
 826                                         'id' => "mw-diff-$id" ) ) );
 827                         return $first . $second;
 828                 } else {
 829                         return '';
 830                 }
 831         }
 832
 833         /**
 834          * This is called if a write operation is possible from the generated HTML
 835          */
 836         function preventClickjacking( $enable = true ) {
 837                 $this->preventClickjacking = $enable;
 838         }
 839
 840         /**
 841          * Get the "prevent clickjacking" flag
 842          * @return bool
 843          */
 844         function getPreventClickjacking() {
 845                 return $this->preventClickjacking;
 846         }
 847 }
 848
 849 /**
 850  * Backwards-compatibility alias
 851  */
 852 class HistoryPage extends HistoryAction {
 853         public function __construct( Page $article ) { # Just to make it public
 854                 parent::__construct( $article );
 855         }
 856
 857         public function history() {
 858                 $this->onView();
 859         }
 860 }