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