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