includes/HistoryPage.php

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