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, $wgSquidMaxage;
  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                 if ( $request->getFullRequestURL() == $this->getTitle()->getInternalURL( 'action=history' ) ) {
 105                         $out->setSquidMaxage( $wgSquidMaxage );
 106                 }
 107
 108                 $this->preCacheMessages();
 109
 110                 # Fill in the file cache if not set already
 111                 if ( $wgUseFileCache && HTMLFileCache::useFileCache( $this->getContext() ) ) {
 112                         $cache = HTMLFileCache::newFromTitle( $this->getTitle(), 'history' );
 113                         if ( !$cache->isCacheGood( /* Assume up to date */ ) ) {
 114                                 ob_start( array( &$cache, 'saveToFileCache' ) );
 115                         }
 116                 }
 117
 118                 // Setup page variables.
 119                 $out->setFeedAppendQuery( 'action=history' );
 120                 $out->addModules( array( 'mediawiki.legacy.history', 'mediawiki.action.history' ) );
 121
 122                 // Handle atom/RSS feeds.
 123                 $feedType = $request->getVal( 'feed' );
 124                 if ( $feedType ) {
 125                         $this->feed( $feedType );
 126                         wfProfileOut( __METHOD__ );
 127                         return;
 128                 }
 129
 130                 // Fail nicely if article doesn't exist.
 131                 if ( !$this->page->exists() ) {
 132                         $out->addWikiMsg( 'nohistory' );
 133                         # show deletion/move log if there is an entry
 134                         LogEventsList::showLogExtract(
 135                                 $out,
 136                                 array( 'delete', 'move' ),
 137                                 $this->getTitle(),
 138                                 '',
 139                                 array(  'lim' => 10,
 140                                         'conds' => array( "log_action != 'revision'" ),
 141                                         'showIfEmpty' => false,
 142                                         'msgKey' => array( 'moveddeleted-notice' )
 143                                 )
 144                         );
 145                         wfProfileOut( __METHOD__ );
 146                         return;
 147                 }
 148
 149                 /**
 150                  * Add date selector to quickly get to a certain time
 151                  */
 152                 $year        = $request->getInt( 'year' );
 153                 $month       = $request->getInt( 'month' );
 154                 $tagFilter   = $request->getVal( 'tagfilter' );
 155                 $tagSelector = ChangeTags::buildTagFilterSelector( $tagFilter );
 156
 157                 /**
 158                  * Option to show only revisions that have been (partially) hidden via RevisionDelete
 159                  */
 160                 if ( $request->getBool( 'deleted' ) ) {
 161                         $conds = array( "rev_deleted != '0'" );
 162                 } else {
 163                         $conds = array();
 164                 }
 165                 $checkDeleted = Xml::checkLabel( $this->msg( 'history-show-deleted' )->text(),
 166                         'deleted', 'mw-show-deleted-only', $request->getBool( 'deleted' ) ) . "\n";
 167
 168                 // Add the general form
 169                 $action = htmlspecialchars( $wgScript );
 170                 $out->addHTML(
 171                         "<form action=\"$action\" method=\"get\" id=\"mw-history-searchform\">" .
 172                         Xml::fieldset(
 173                                 $this->msg( 'history-fieldset-title' )->text(),
 174                                 false,
 175                                 array( 'id' => 'mw-history-search' )
 176                         ) .
 177                         Html::hidden( 'title', $this->getTitle()->getPrefixedDBKey() ) . "\n" .
 178                         Html::hidden( 'action', 'history' ) . "\n" .
 179                         Xml::dateMenu( $year, $month ) . '&#160;' .
 180                         ( $tagSelector ? ( implode( '&#160;', $tagSelector ) . '&#160;' ) : '' ) .
 181                         $checkDeleted .
 182                         Xml::submitButton( $this->msg( 'allpagessubmit' )->text() ) . "\n" .
 183                         '</fieldset></form>'
 184                 );
 185
 186                 wfRunHooks( 'PageHistoryBeforeList', array( &$this->page ) );
 187
 188                 // Create and output the list.
 189                 $pager = new HistoryPager( $this, $year, $month, $tagFilter, $conds );
 190                 $out->addHTML(
 191                         $pager->getNavigationBar() .
 192                         $pager->getBody() .
 193                         $pager->getNavigationBar()
 194                 );
 195                 $out->preventClickjacking( $pager->getPreventClickjacking() );
 196
 197                 wfProfileOut( __METHOD__ );
 198         }
 199
 200         /**
 201          * Fetch an array of revisions, specified by a given limit, offset and
 202          * direction. This is now only used by the feeds. It was previously
 203          * used by the main UI but that's now handled by the pager.
 204          *
 205          * @param $limit Integer: the limit number of revisions to get
 206          * @param $offset Integer
 207          * @param $direction Integer: either HistoryPage::DIR_PREV or HistoryPage::DIR_NEXT
 208          * @return ResultWrapper
 209          */
 210         function fetchRevisions( $limit, $offset, $direction ) {
 211                 $dbr = wfGetDB( DB_SLAVE );
 212
 213                 if ( $direction == HistoryPage::DIR_PREV ) {
 214                         list( $dirs, $oper ) = array( "ASC", ">=" );
 215                 } else { /* $direction == HistoryPage::DIR_NEXT */
 216                         list( $dirs, $oper ) = array( "DESC", "<=" );
 217                 }
 218
 219                 if ( $offset ) {
 220                         $offsets = array( "rev_timestamp $oper '$offset'" );
 221                 } else {
 222                         $offsets = array();
 223                 }
 224
 225                 $page_id = $this->page->getId();
 226
 227                 return $dbr->select( 'revision',
 228                         Revision::selectFields(),
 229                         array_merge( array( "rev_page=$page_id" ), $offsets ),
 230                         __METHOD__,
 231                         array( 'ORDER BY' => "rev_timestamp $dirs",
 232                                 'USE INDEX' => 'page_timestamp', 'LIMIT' => $limit )
 233                 );
 234         }
 235
 236         /**
 237          * Output a subscription feed listing recent edits to this page.
 238          *
 239          * @param $type String: feed type
 240          */
 241         function feed( $type ) {
 242                 global $wgFeedClasses, $wgFeedLimit;
 243                 if ( !FeedUtils::checkFeedOutput( $type ) ) {
 244                         return;
 245                 }
 246                 $request = $this->getRequest();
 247
 248                 $feed = new $wgFeedClasses[$type](
 249                         $this->getTitle()->getPrefixedText() . ' - ' .
 250                         wfMsgForContent( 'history-feed-title' ),
 251                         wfMsgForContent( 'history-feed-description' ),
 252                         $this->getTitle()->getFullUrl( 'action=history' )
 253                 );
 254
 255                 // Get a limit on number of feed entries. Provide a sane default
 256                 // of 10 if none is defined (but limit to $wgFeedLimit max)
 257                 $limit = $request->getInt( 'limit', 10 );
 258                 if ( $limit > $wgFeedLimit || $limit < 1 ) {
 259                         $limit = 10;
 260                 }
 261                 $items = $this->fetchRevisions( $limit, 0, HistoryPage::DIR_NEXT );
 262
 263                 // Generate feed elements enclosed between header and footer.
 264                 $feed->outHeader();
 265                 if ( $items->numRows() ) {
 266                         foreach ( $items as $row ) {
 267                                 $feed->outItem( $this->feedItem( $row ) );
 268                         }
 269                 } else {
 270                         $feed->outItem( $this->feedEmpty() );
 271                 }
 272                 $feed->outFooter();
 273         }
 274
 275         function feedEmpty() {
 276                 return new FeedItem(
 277                         wfMsgForContent( 'nohistory' ),
 278                         $this->getOutput()->parse( wfMsgForContent( 'history-feed-empty' ) ),
 279                         $this->getTitle()->getFullUrl(),
 280                         wfTimestamp( TS_MW ),
 281                         '',
 282                         $this->getTitle()->getTalkPage()->getFullUrl()
 283                 );
 284         }
 285
 286         /**
 287          * Generate a FeedItem object from a given revision table row
 288          * Borrows Recent Changes' feed generation functions for formatting;
 289          * includes a diff to the previous revision (if any).
 290          *
 291          * @param $row Object: database row
 292          * @return FeedItem
 293          */
 294         function feedItem( $row ) {
 295                 $rev = new Revision( $row );
 296                 $rev->setTitle( $this->getTitle() );
 297                 $text = FeedUtils::formatDiffRow(
 298                         $this->getTitle(),
 299                         $this->getTitle()->getPreviousRevisionID( $rev->getId() ),
 300                         $rev->getId(),
 301                         $rev->getTimestamp(),
 302                         $rev->getComment()
 303                 );
 304                 if ( $rev->getComment() == '' ) {
 305                         global $wgContLang;
 306                         $title = wfMsgForContent( 'history-feed-item-nocomment',
 307                                 $rev->getUserText(),
 308                                 $wgContLang->timeanddate( $rev->getTimestamp() ),
 309                                 $wgContLang->date( $rev->getTimestamp() ),
 310                                 $wgContLang->time( $rev->getTimestamp() )
 311                         );
 312                 } else {
 313                         $title = $rev->getUserText() .
 314                         wfMsgForContent( 'colon-separator' ) .
 315                         FeedItem::stripComment( $rev->getComment() );
 316                 }
 317                 return new FeedItem(
 318                         $title,
 319                         $text,
 320                         $this->getTitle()->getFullUrl( 'diff=' . $rev->getId() . '&oldid=prev' ),
 321                         $rev->getTimestamp(),
 322                         $rev->getUserText(),
 323                         $this->getTitle()->getTalkPage()->getFullUrl()
 324                 );
 325         }
 326 }
 327
 328 /**
 329  * @ingroup Pager
 330  */
 331 class HistoryPager extends ReverseChronologicalPager {
 332         public $lastRow = false, $counter, $historyPage, $buttons, $conds;
 333         protected $oldIdChecked;
 334         protected $preventClickjacking = false;
 335         /**
 336          * @var array
 337          */
 338         protected $parentLens;
 339
 340         function __construct( $historyPage, $year = '', $month = '', $tagFilter = '', $conds = array() ) {
 341                 parent::__construct( $historyPage->getContext() );
 342                 $this->historyPage = $historyPage;
 343                 $this->tagFilter = $tagFilter;
 344                 $this->getDateCond( $year, $month );
 345                 $this->conds = $conds;
 346         }
 347
 348         // For hook compatibility...
 349         function getArticle() {
 350                 return $this->historyPage->getArticle();
 351         }
 352
 353         function getSqlComment() {
 354                 if ( $this->conds ) {
 355                         return 'history page filtered'; // potentially slow, see CR r58153
 356                 } else {
 357                         return 'history page unfiltered';
 358                 }
 359         }
 360
 361         function getQueryInfo() {
 362                 $queryInfo = array(
 363                         'tables'  => array( 'revision', 'user' ),
 364                         'fields'  => array_merge( Revision::selectFields(), Revision::selectUserFields() ),
 365                         'conds'   => array_merge(
 366                                 array( 'rev_page' => $this->getWikiPage()->getId() ),
 367                                 $this->conds ),
 368                         'options' => array( 'USE INDEX' => array( 'revision' => 'page_timestamp' ) ),
 369                         'join_conds' => array(
 370                                 'user'        => Revision::userJoinCond(),
 371                                 'tag_summary' => array( 'LEFT JOIN', 'ts_rev_id=rev_id' ) ),
 372                 );
 373                 ChangeTags::modifyDisplayQuery(
 374                         $queryInfo['tables'],
 375                         $queryInfo['fields'],
 376                         $queryInfo['conds'],
 377                         $queryInfo['join_conds'],
 378                         $queryInfo['options'],
 379                         $this->tagFilter
 380                 );
 381                 wfRunHooks( 'PageHistoryPager::getQueryInfo', array( &$this, &$queryInfo ) );
 382                 return $queryInfo;
 383         }
 384
 385         function getIndexField() {
 386                 return 'rev_timestamp';
 387         }
 388
 389         function formatRow( $row ) {
 390                 if ( $this->lastRow ) {
 391                         $latest = ( $this->counter == 1 && $this->mIsFirst );
 392                         $firstInList = $this->counter == 1;
 393                         $this->counter++;
 394                         $s = $this->historyLine( $this->lastRow, $row,
 395                                 $this->getTitle()->getNotificationTimestamp( $this->getUser() ), $latest, $firstInList );
 396                 } else {
 397                         $s = '';
 398                 }
 399                 $this->lastRow = $row;
 400                 return $s;
 401         }
 402
 403         function doBatchLookups() {
 404                 # Do a link batch query
 405                 $this->mResult->seek( 0 );
 406                 $batch = new LinkBatch();
 407                 $revIds = array();
 408                 foreach ( $this->mResult as $row ) {
 409                         if( $row->rev_parent_id ) {
 410                                 $revIds[] = $row->rev_parent_id;
 411                         }
 412                         if( !is_null( $row->user_name ) ) {
 413                                 $batch->add( NS_USER, $row->user_name );
 414                                 $batch->add( NS_USER_TALK, $row->user_name );
 415                         } else { # for anons or usernames of imported revisions
 416                                 $batch->add( NS_USER, $row->rev_user_text );
 417                                 $batch->add( NS_USER_TALK, $row->rev_user_text );
 418                         }
 419                 }
 420                 $this->parentLens = $this->getParentLengths( $revIds );
 421                 $batch->execute();
 422                 $this->mResult->seek( 0 );
 423         }
 424
 425         /**
 426          * Do a batched query to get the parent revision lengths
 427          * @param $revIds array
 428          * @return array
 429          * @TODO: stolen from Contributions, refactor
 430          */
 431         private function getParentLengths( array $revIds ) {
 432                 $revLens = array();
 433                 if ( !$revIds ) {
 434                         return $revLens; // empty
 435                 }
 436                 wfProfileIn( __METHOD__ );
 437                 $res = $this->mDb->select( 'revision',
 438                         array( 'rev_id', 'rev_len' ),
 439                         array( 'rev_id' => $revIds ),
 440                         __METHOD__ );
 441                 foreach ( $res as $row ) {
 442                         $revLens[$row->rev_id] = $row->rev_len;
 443                 }
 444                 wfProfileOut( __METHOD__ );
 445                 return $revLens;
 446         }
 447
 448         /**
 449          * Creates begin of history list with a submit button
 450          *
 451          * @return string HTML output
 452          */
 453         function getStartBody() {
 454                 global $wgScript;
 455                 $this->lastRow = false;
 456                 $this->counter = 1;
 457                 $this->oldIdChecked = 0;
 458
 459                 $this->getOutput()->wrapWikiMsg( "<div class='mw-history-legend'>\n$1\n</div>", 'histlegend' );
 460                 $s = Html::openElement( 'form', array( 'action' => $wgScript,
 461                         'id' => 'mw-history-compare' ) ) . "\n";
 462                 $s .= Html::hidden( 'title', $this->getTitle()->getPrefixedDbKey() ) . "\n";
 463                 $s .= Html::hidden( 'action', 'historysubmit' ) . "\n";
 464
 465                 // Button container stored in $this->buttons for re-use in getEndBody()
 466                 $this->buttons = '<div>';
 467                 $this->buttons .= $this->submitButton( $this->msg( 'compareselectedversions' )->text(),
 468                         array( 'class' => 'historysubmit mw-history-compareselectedversions-button' )
 469                                 + Linker::tooltipAndAccesskeyAttribs( 'compareselectedversions' )
 470                 ) . "\n";
 471
 472                 if ( $this->getUser()->isAllowed( 'deleterevision' ) ) {
 473                         $this->buttons .= $this->getRevisionButton( 'revisiondelete', 'showhideselectedversions' );
 474                 }
 475                 $this->buttons .= '</div>';
 476
 477                 $s .= $this->buttons;
 478                 $s .= '<ul id="pagehistory">' . "\n";
 479                 return $s;
 480         }
 481
 482         private function getRevisionButton( $name, $msg ) {
 483                 $this->preventClickjacking();
 484                 # Note bug #20966, <button> is non-standard in IE<8
 485                 $element = Html::element( 'button',
 486                         array(
 487                                 'type' => 'submit',
 488                                 'name' => $name,
 489                                 'value' => '1',
 490                                 'class' => "historysubmit mw-history-$name-button",
 491                         ),
 492                         $this->msg( $msg )->text()
 493                 ) . "\n";
 494                 return $element;
 495         }
 496
 497         function getEndBody() {
 498                 if ( $this->lastRow ) {
 499                         $latest = $this->counter == 1 && $this->mIsFirst;
 500                         $firstInList = $this->counter == 1;
 501                         if ( $this->mIsBackwards ) {
 502                                 # Next row is unknown, but for UI reasons, probably exists if an offset has been specified
 503                                 if ( $this->mOffset == '' ) {
 504                                         $next = null;
 505                                 } else {
 506                                         $next = 'unknown';
 507                                 }
 508                         } else {
 509                                 # The next row is the past-the-end row
 510                                 $next = $this->mPastTheEndRow;
 511                         }
 512                         $this->counter++;
 513                         $s = $this->historyLine( $this->lastRow, $next,
 514                                 $this->getTitle()->getNotificationTimestamp( $this->getUser() ), $latest, $firstInList );
 515                 } else {
 516                         $s = '';
 517                 }
 518                 $s .= "</ul>\n";
 519                 # Add second buttons only if there is more than one rev
 520                 if ( $this->getNumRows() > 2 ) {
 521                         $s .= $this->buttons;
 522                 }
 523                 $s .= '</form>';
 524                 return $s;
 525         }
 526
 527         /**
 528          * Creates a submit button
 529          *
 530          * @param $message String: text of the submit button, will be escaped
 531          * @param $attributes Array: attributes
 532          * @return String: HTML output for the submit button
 533          */
 534         function submitButton( $message, $attributes = array() ) {
 535                 # Disable submit button if history has 1 revision only
 536                 if ( $this->getNumRows() > 1 ) {
 537                         return Xml::submitButton( $message , $attributes );
 538                 } else {
 539                         return '';
 540                 }
 541         }
 542
 543         /**
 544          * Returns a row from the history printout.
 545          *
 546          * @todo document some more, and maybe clean up the code (some params redundant?)
 547          *
 548          * @param $row Object: the database row corresponding to the previous line.
 549          * @param $next Mixed: the database row corresponding to the next line. (chronologically previous)
 550          * @param $notificationtimestamp
 551          * @param $latest Boolean: whether this row corresponds to the page's latest revision.
 552          * @param $firstInList Boolean: whether this row corresponds to the first displayed on this history page.
 553          * @return String: HTML output for the row
 554          */
 555         function historyLine( $row, $next, $notificationtimestamp = false,
 556                 $latest = false, $firstInList = false )
 557         {
 558                 $rev = new Revision( $row );
 559                 $rev->setTitle( $this->getTitle() );
 560
 561                 if ( is_object( $next ) ) {
 562                         $prevRev = new Revision( $next );
 563                         $prevRev->setTitle( $this->getTitle() );
 564                 } else {
 565                         $prevRev = null;
 566                 }
 567
 568                 $curlink = $this->curLink( $rev, $latest );
 569                 $lastlink = $this->lastLink( $rev, $next );
 570                 $diffButtons = $this->diffButtons( $rev, $firstInList );
 571                 $histLinks = Html::rawElement(
 572                                 'span',
 573                                 array( 'class' => 'mw-history-histlinks' ),
 574                                 $this->msg( 'parentheses' )->rawParams( $curlink . $this->historyPage->message['pipe-separator'] . $lastlink )->escaped()
 575                 );
 576                 $s = $histLinks . $diffButtons;
 577
 578                 $link = $this->revLink( $rev );
 579                 $classes = array();
 580
 581                 $del = '';
 582                 $user = $this->getUser();
 583                 // Show checkboxes for each revision
 584                 if ( $user->isAllowed( 'deleterevision' ) ) {
 585                         $this->preventClickjacking();
 586                         // If revision was hidden from sysops, disable the checkbox
 587                         if ( !$rev->userCan( Revision::DELETED_RESTRICTED, $user ) ) {
 588                                 $del = Xml::check( 'deleterevisions', false, array( 'disabled' => 'disabled' ) );
 589                         // Otherwise, enable the checkbox...
 590                         } else {
 591                                 $del = Xml::check( 'showhiderevisions', false,
 592                                         array( 'name' => 'ids[' . $rev->getId() . ']' ) );
 593                         }
 594                 // User can only view deleted revisions...
 595                 } elseif ( $rev->getVisibility() && $user->isAllowed( 'deletedhistory' ) ) {
 596                         // If revision was hidden from sysops, disable the link
 597                         if ( !$rev->userCan( Revision::DELETED_RESTRICTED, $user ) ) {
 598                                 $cdel = Linker::revDeleteLinkDisabled( false );
 599                         // Otherwise, show the link...
 600                         } else {
 601                                 $query = array( 'type' => 'revision',
 602                                         'target' => $this->getTitle()->getPrefixedDbkey(), 'ids' => $rev->getId() );
 603                                 $del .= Linker::revDeleteLink( $query,
 604                                         $rev->isDeleted( Revision::DELETED_RESTRICTED ), false );
 605                         }
 606                 }
 607                 if ( $del ) {
 608                         $s .= " $del ";
 609                 }
 610
 611                 $lang = $this->getLanguage();
 612                 $dirmark = $lang->getDirMark();
 613
 614                 $s .= " $link";
 615                 $s .= $dirmark;
 616                 $s .= " <span class='history-user'>" .
 617                         Linker::revUserTools( $rev, true ) . "</span>";
 618                 $s .= $dirmark;
 619
 620                 if ( $rev->isMinor() ) {
 621                         $s .= ' ' . ChangesList::flag( 'minor' );
 622                 }
 623
 624                 # Size is always public data
 625                 $prevSize = isset( $this->parentLens[$row->rev_parent_id] )
 626                         ? $this->parentLens[$row->rev_parent_id]
 627                         : 0;
 628                 $sDiff = ChangesList::showCharacterDifference( $prevSize, $rev->getSize() );
 629                 $fSize = Linker::formatRevisionSize($rev->getSize());
 630                 $s .= " . . $fSize $sDiff";
 631
 632                 # Text following the character difference is added just before running hooks
 633                 $s2 = Linker::revComment( $rev, false, true );
 634
 635                 if ( $notificationtimestamp && ( $row->rev_timestamp >= $notificationtimestamp ) ) {
 636                         $s2 .= ' <span class="updatedmarker">' .  $this->msg( 'updatedmarker' )->escaped() . '</span>';
 637                 }
 638
 639                 $tools = array();
 640
 641                 # Rollback and undo links
 642                 if ( $prevRev &&
 643                         !count( $this->getTitle()->getUserPermissionsErrors( 'edit', $this->getUser() ) ) )
 644                 {
 645                         if ( $latest && !count( $this->getTitle()->getUserPermissionsErrors( 'rollback', $this->getUser() ) ) ) {
 646                                 $this->preventClickjacking();
 647                                 $tools[] = '<span class="mw-rollback-link">' .
 648                                         Linker::buildRollbackLink( $rev ) . '</span>';
 649                         }
 650
 651                         if ( !$rev->isDeleted( Revision::DELETED_TEXT )
 652                                 && !$prevRev->isDeleted( Revision::DELETED_TEXT ) )
 653                         {
 654                                 # Create undo tooltip for the first (=latest) line only
 655                                 $undoTooltip = $latest
 656                                         ? array( 'title' => $this->msg( 'tooltip-undo' )->text() )
 657                                         : array();
 658                                 $undolink = Linker::linkKnown(
 659                                         $this->getTitle(),
 660                                         $this->msg( 'editundo' )->escaped(),
 661                                         $undoTooltip,
 662                                         array(
 663                                                 'action'    => 'edit',
 664                                                 'undoafter' => $prevRev->getId(),
 665                                                 'undo'      => $rev->getId()
 666                                         )
 667                                 );
 668                                 $tools[] = "<span class=\"mw-history-undo\">{$undolink}</span>";
 669                         }
 670                 }
 671
 672                 if ( $tools ) {
 673                         $s2 .= ' '. $this->msg( 'parentheses' )->rawParams( $lang->pipeList( $tools ) )->escaped();
 674                 }
 675
 676                 # Tags
 677                 list( $tagSummary, $newClasses ) = ChangeTags::formatSummaryRow( $row->ts_tags, 'history' );
 678                 $classes = array_merge( $classes, $newClasses );
 679                 if ( $tagSummary !== '' ) {
 680                         $s2 .= " $tagSummary";
 681                 }
 682
 683                 # Include separator between character difference and following text
 684                 if ( $s2 !== '' ) {
 685                         $s .= " . . $s2";
 686                 }
 687
 688                 wfRunHooks( 'PageHistoryLineEnding', array( $this, &$row , &$s, &$classes ) );
 689
 690                 $attribs = array();
 691                 if ( $classes ) {
 692                         $attribs['class'] = implode( ' ', $classes );
 693                 }
 694
 695                 return Xml::tags( 'li', $attribs, $s ) . "\n";
 696         }
 697
 698         /**
 699          * Create a link to view this revision of the page
 700          *
 701          * @param $rev Revision
 702          * @return String
 703          */
 704         function revLink( $rev ) {
 705                 $date = $this->getLanguage()->userTimeAndDate( $rev->getTimestamp(), $this->getUser() );
 706                 $date = htmlspecialchars( $date );
 707                 if ( $rev->userCan( Revision::DELETED_TEXT, $this->getUser() ) ) {
 708                         $link = Linker::linkKnown(
 709                                 $this->getTitle(),
 710                                 $date,
 711                                 array(),
 712                                 array( 'oldid' => $rev->getId() )
 713                         );
 714                 } else {
 715                         $link = $date;
 716                 }
 717                 if ( $rev->isDeleted( Revision::DELETED_TEXT ) ) {
 718                         $link = "<span class=\"history-deleted\">$link</span>";
 719                 }
 720                 return $link;
 721         }
 722
 723         /**
 724          * Create a diff-to-current link for this revision for this page
 725          *
 726          * @param $rev Revision
 727          * @param $latest Boolean: this is the latest revision of the page?
 728          * @return String
 729          */
 730         function curLink( $rev, $latest ) {
 731                 $cur = $this->historyPage->message['cur'];
 732                 if ( $latest || !$rev->userCan( Revision::DELETED_TEXT, $this->getUser() ) ) {
 733                         return $cur;
 734                 } else {
 735                         return Linker::linkKnown(
 736                                 $this->getTitle(),
 737                                 $cur,
 738                                 array(),
 739                                 array(
 740                                         'diff' => $this->getWikiPage()->getLatest(),
 741                                         'oldid' => $rev->getId()
 742                                 )
 743                         );
 744                 }
 745         }
 746
 747         /**
 748          * Create a diff-to-previous link for this revision for this page.
 749          *
 750          * @param $prevRev Revision: the previous revision
 751          * @param $next Mixed: the newer revision
 752          * @return String
 753          */
 754         function lastLink( $prevRev, $next ) {
 755                 $last = $this->historyPage->message['last'];
 756                 # $next may either be a Row, null, or "unkown"
 757                 $nextRev = is_object( $next ) ? new Revision( $next ) : $next;
 758                 if ( is_null( $next ) ) {
 759                         # Probably no next row
 760                         return $last;
 761                 } elseif ( $next === 'unknown' ) {
 762                         # Next row probably exists but is unknown, use an oldid=prev link
 763                         return Linker::linkKnown(
 764                                 $this->getTitle(),
 765                                 $last,
 766                                 array(),
 767                                 array(
 768                                         'diff' => $prevRev->getId(),
 769                                         'oldid' => 'prev'
 770                                 )
 771                         );
 772                 } elseif ( !$prevRev->userCan( Revision::DELETED_TEXT, $this->getUser() )
 773                         || !$nextRev->userCan( Revision::DELETED_TEXT, $this->getUser() ) )
 774                 {
 775                         return $last;
 776                 } else {
 777                         return Linker::linkKnown(
 778                                 $this->getTitle(),
 779                                 $last,
 780                                 array(),
 781                                 array(
 782                                         'diff' => $prevRev->getId(),
 783                                         'oldid' => $next->rev_id
 784                                 )
 785                         );
 786                 }
 787         }
 788
 789         /**
 790          * Create radio buttons for page history
 791          *
 792          * @param $rev Revision object
 793          * @param $firstInList Boolean: is this version the first one?
 794          *
 795          * @return String: HTML output for the radio buttons
 796          */
 797         function diffButtons( $rev, $firstInList ) {
 798                 if ( $this->getNumRows() > 1 ) {
 799                         $id = $rev->getId();
 800                         $radio = array( 'type'  => 'radio', 'value' => $id );
 801                         /** @todo: move title texts to javascript */
 802                         if ( $firstInList ) {
 803                                 $first = Xml::element( 'input',
 804                                         array_merge( $radio, array(
 805                                                 'style' => 'visibility:hidden',
 806                                                 'name'  => 'oldid',
 807                                                 'id' => 'mw-oldid-null' ) )
 808                                 );
 809                                 $checkmark = array( 'checked' => 'checked' );
 810                         } else {
 811                                 # Check visibility of old revisions
 812                                 if ( !$rev->userCan( Revision::DELETED_TEXT, $this->getUser() ) ) {
 813                                         $radio['disabled'] = 'disabled';
 814                                         $checkmark = array(); // We will check the next possible one
 815                                 } elseif ( !$this->oldIdChecked ) {
 816                                         $checkmark = array( 'checked' => 'checked' );
 817                                         $this->oldIdChecked = $id;
 818                                 } else {
 819                                         $checkmark = array();
 820                                 }
 821                                 $first = Xml::element( 'input',
 822                                         array_merge( $radio, $checkmark, array(
 823                                                 'name'  => 'oldid',
 824                                                 'id' => "mw-oldid-$id" ) ) );
 825                                 $checkmark = array();
 826                         }
 827                         $second = Xml::element( 'input',
 828                                 array_merge( $radio, $checkmark, array(
 829                                         'name'  => 'diff',
 830                                         'id' => "mw-diff-$id" ) ) );
 831                         return $first . $second;
 832                 } else {
 833                         return '';
 834                 }
 835         }
 836
 837         /**
 838          * This is called if a write operation is possible from the generated HTML
 839          */
 840         function preventClickjacking( $enable = true ) {
 841                 $this->preventClickjacking = $enable;
 842         }
 843
 844         /**
 845          * Get the "prevent clickjacking" flag
 846          * @return bool
 847          */
 848         function getPreventClickjacking() {
 849                 return $this->preventClickjacking;
 850         }
 851 }
 852
 853 /**
 854  * Backwards-compatibility alias
 855  */
 856 class HistoryPage extends HistoryAction {
 857         public function __construct( Page $article ) { # Just to make it public
 858                 parent::__construct( $article );
 859         }
 860
 861         public function history() {
 862                 $this->onView();
 863         }
 864 }