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          * @returns nothing
  29          */
  30         function __construct( $article ) {
  31                 global $wgUser;
  32                 $this->article = $article;
  33                 $this->title = $article->getTitle();
  34                 $this->skin = $wgUser->getSkin();
  35                 $this->preCacheMessages();
  36         }
  37
  38         function getArticle() {
  39                 return $this->article;
  40         }
  41
  42         function getTitle() {
  43                 return $this->title;
  44         }
  45
  46         /**
  47          * As we use the same small set of messages in various methods and that
  48          * they are called often, we call them once and save them in $this->message
  49          */
  50         function preCacheMessages() {
  51                 // Precache various messages
  52                 if( !isset( $this->message ) ) {
  53                         foreach( explode(' ', 'cur last rev-delundel' ) as $msg ) {
  54                                 $this->message[$msg] = wfMsgExt( $msg, array( 'escape') );
  55                         }
  56                 }
  57         }
  58
  59         /**
  60          * Print the history page for an article.
  61          *
  62          * @returns nothing
  63          */
  64         function history() {
  65                 global $wgOut, $wgRequest, $wgScript;
  66
  67                 /*
  68                  * Allow client caching.
  69                  */
  70                 if( $wgOut->checkLastModified( $this->article->getTouched() ) )
  71                         return; // Client cache fresh and headers sent, nothing more to do.
  72
  73                 wfProfileIn( __METHOD__ );
  74
  75                 /*
  76                  * Setup page variables.
  77                  */
  78                 $wgOut->setPageTitle( wfMsg( 'history-title', $this->title->getPrefixedText() ) );
  79                 $wgOut->setPageTitleActionText( wfMsg( 'history_short' ) );
  80                 $wgOut->setArticleFlag( false );
  81                 $wgOut->setArticleRelated( true );
  82                 $wgOut->setRobotPolicy( 'noindex,nofollow' );
  83                 $wgOut->setSyndicated( true );
  84                 $wgOut->setFeedAppendQuery( 'action=history' );
  85                 $wgOut->addScriptFile( 'history.js' );
  86
  87                 $logPage = SpecialPage::getTitleFor( 'Log' );
  88                 $logLink = $this->skin->link(
  89                         $logPage,
  90                         wfMsgHtml( 'viewpagelogs' ),
  91                         array(),
  92                         array( 'page' => $this->title->getPrefixedText() ),
  93                         array( 'known', 'noclasses' )
  94                 );
  95                 $wgOut->setSubtitle( $logLink );
  96
  97                 $feedType = $wgRequest->getVal( 'feed' );
  98                 if( $feedType ) {
  99                         wfProfileOut( __METHOD__ );
 100                         return $this->feed( $feedType );
 101                 }
 102
 103                 /*
 104                  * Fail if article doesn't exist.
 105                  */
 106                 if( !$this->title->exists() ) {
 107                         $wgOut->addWikiMsg( 'nohistory' );
 108                         # show deletion/move log if there is an entry
 109                         LogEventsList::showLogExtract( $wgOut, array( 'delete', 'move' ), $this->title->getPrefixedText(), '',
 110                                 array(  'lim' => 10,
 111                                         'conds' => array( "log_action != 'revision'" ),
 112                                         'showIfEmpty' => false,
 113                                         'msgKey' => array( 'moveddeleted-notice' ) )
 114                         );
 115                         wfProfileOut( __METHOD__ );
 116                         return;
 117                 }
 118
 119                 /**
 120                  * Add date selector to quickly get to a certain time
 121                  */
 122                 $year = $wgRequest->getInt( 'year' );
 123                 $month = $wgRequest->getInt( 'month' );
 124                 $tagFilter = $wgRequest->getVal( 'tagfilter' );
 125                 $tagSelector = ChangeTags::buildTagFilterSelector( $tagFilter );
 126
 127                 $action = htmlspecialchars( $wgScript );
 128                 $wgOut->addHTML(
 129                         "<form action=\"$action\" method=\"get\" id=\"mw-history-searchform\">" .
 130                         Xml::fieldset( wfMsg( 'history-fieldset-title' ), false, array( 'id' => 'mw-history-search' ) ) .
 131                         Xml::hidden( 'title', $this->title->getPrefixedDBKey() ) . "\n" .
 132                         Xml::hidden( 'action', 'history' ) . "\n" .
 133                         xml::dateMenu( $year, $month ) . '&nbsp;' .
 134                         ( $tagSelector ? ( implode( '&nbsp;', $tagSelector ) . '&nbsp;' ) : '' ) .
 135                         Xml::submitButton( wfMsg( 'allpagessubmit' ) ) . "\n" .
 136                         '</fieldset></form>'
 137                 );
 138
 139                 wfRunHooks( 'PageHistoryBeforeList', array( &$this->article ) );
 140
 141                 /**
 142                  * Do the list
 143                  */
 144                 $pager = new HistoryPager( $this, $year, $month, $tagFilter );
 145                 $wgOut->addHTML(
 146                         $pager->getNavigationBar() .
 147                         $pager->getBody() .
 148                         $pager->getNavigationBar()
 149                 );
 150
 151                 wfProfileOut( __METHOD__ );
 152         }
 153
 154         /**
 155          * Fetch an array of revisions, specified by a given limit, offset and
 156          * direction. This is now only used by the feeds. It was previously
 157          * used by the main UI but that's now handled by the pager.
 158          */
 159         function fetchRevisions($limit, $offset, $direction) {
 160                 $dbr = wfGetDB( DB_SLAVE );
 161
 162                 if( $direction == HistoryPage::DIR_PREV )
 163                         list($dirs, $oper) = array("ASC", ">=");
 164                 else /* $direction == HistoryPage::DIR_NEXT */
 165                         list($dirs, $oper) = array("DESC", "<=");
 166
 167                 if( $offset )
 168                         $offsets = array("rev_timestamp $oper '$offset'");
 169                 else
 170                         $offsets = array();
 171
 172                 $page_id = $this->title->getArticleID();
 173
 174                 return $dbr->select( 'revision',
 175                         Revision::selectFields(),
 176                         array_merge(array("rev_page=$page_id"), $offsets),
 177                         __METHOD__,
 178                         array( 'ORDER BY' => "rev_timestamp $dirs",
 179                                 'USE INDEX' => 'page_timestamp', 'LIMIT' => $limit)
 180                 );
 181         }
 182
 183         /**
 184          * Output a subscription feed listing recent edits to this page.
 185          * @param string $type
 186          */
 187         function feed( $type ) {
 188                 global $wgFeedClasses, $wgRequest, $wgFeedLimit;
 189                 if( !FeedUtils::checkFeedOutput($type) ) {
 190                         return;
 191                 }
 192
 193                 $feed = new $wgFeedClasses[$type](
 194                 $this->title->getPrefixedText() . ' - ' .
 195                 wfMsgForContent( 'history-feed-title' ),
 196                 wfMsgForContent( 'history-feed-description' ),
 197                 $this->title->getFullUrl( 'action=history' ) );
 198
 199                 // Get a limit on number of feed entries. Provide a sane default
 200                 // of 10 if none is defined (but limit to $wgFeedLimit max)
 201                 $limit = $wgRequest->getInt( 'limit', 10 );
 202                 if( $limit > $wgFeedLimit || $limit < 1 ) {
 203                         $limit = 10;
 204                 }
 205                 $items = $this->fetchRevisions($limit, 0, HistoryPage::DIR_NEXT);
 206
 207                 $feed->outHeader();
 208                 if( $items ) {
 209                         foreach( $items as $row ) {
 210                                 $feed->outItem( $this->feedItem( $row ) );
 211                         }
 212                 } else {
 213                         $feed->outItem( $this->feedEmpty() );
 214                 }
 215                 $feed->outFooter();
 216         }
 217
 218         function feedEmpty() {
 219                 global $wgOut;
 220                 return new FeedItem(
 221                         wfMsgForContent( 'nohistory' ),
 222                         $wgOut->parse( wfMsgForContent( 'history-feed-empty' ) ),
 223                         $this->title->getFullUrl(),
 224                         wfTimestamp( TS_MW ),
 225                         '',
 226                         $this->title->getTalkPage()->getFullUrl()
 227                 );
 228         }
 229
 230         /**
 231          * Generate a FeedItem object from a given revision table row
 232          * Borrows Recent Changes' feed generation functions for formatting;
 233          * includes a diff to the previous revision (if any).
 234          *
 235          * @param $row
 236          * @return FeedItem
 237          */
 238         function feedItem( $row ) {
 239                 $rev = new Revision( $row );
 240                 $rev->setTitle( $this->title );
 241                 $text = FeedUtils::formatDiffRow(
 242                         $this->title,
 243                         $this->title->getPreviousRevisionID( $rev->getId() ),
 244                         $rev->getId(),
 245                         $rev->getTimestamp(),
 246                         $rev->getComment()
 247                 );
 248                 if( $rev->getComment() == '' ) {
 249                         global $wgContLang;
 250                         $title = wfMsgForContent( 'history-feed-item-nocomment',
 251                         $rev->getUserText(),
 252                         $wgContLang->timeanddate( $rev->getTimestamp() ) );
 253                 } else {
 254                         $title = $rev->getUserText() . wfMsgForContent( 'colon-separator' ) . FeedItem::stripComment( $rev->getComment() );
 255                 }
 256                 return new FeedItem(
 257                         $title,
 258                         $text,
 259                         $this->title->getFullUrl( 'diff=' . $rev->getId() . '&oldid=prev' ),
 260                         $rev->getTimestamp(),
 261                         $rev->getUserText(),
 262                         $this->title->getTalkPage()->getFullUrl()
 263                 );
 264         }
 265 }
 266
 267
 268 /**
 269  * @ingroup Pager
 270  */
 271 class HistoryPager extends ReverseChronologicalPager {
 272         public $lastRow = false, $counter, $historyPage, $title, $buttons;
 273         protected $oldIdChecked;
 274
 275         function __construct( $historyPage, $year='', $month='', $tagFilter = '' ) {
 276                 parent::__construct();
 277                 $this->historyPage = $historyPage;
 278                 $this->title = $this->historyPage->title;
 279                 $this->tagFilter = $tagFilter;
 280                 $this->getDateCond( $year, $month );
 281         }
 282
 283         // For hook compatibility...
 284         function getArticle() {
 285                 return $this->historyPage->getArticle();
 286         }
 287
 288         function getQueryInfo() {
 289                 $queryInfo = array(
 290                         'tables'  => array('revision'),
 291                         'fields'  => array_merge( Revision::selectFields(), array('ts_tags') ),
 292                         'conds'   => array('rev_page' => $this->historyPage->title->getArticleID() ),
 293                         'options' => array( 'USE INDEX' => array('revision' => 'page_timestamp') ),
 294                         'join_conds' => array( 'tag_summary' => array( 'LEFT JOIN', 'ts_rev_id=rev_id' ) ),
 295                 );
 296                 ChangeTags::modifyDisplayQuery( $queryInfo['tables'],
 297                                                                                 $queryInfo['fields'],
 298                                                                                 $queryInfo['conds'],
 299                                                                                 $queryInfo['join_conds'],
 300                                                                                 $queryInfo['options'],
 301                                                                                 $this->tagFilter );
 302                 wfRunHooks( 'PageHistoryPager::getQueryInfo', array( &$this, &$queryInfo ) );
 303                 return $queryInfo;
 304         }
 305
 306         function getIndexField() {
 307                 return 'rev_timestamp';
 308         }
 309
 310         function formatRow( $row ) {
 311                 if( $this->lastRow ) {
 312                         $latest = ($this->counter == 1 && $this->mIsFirst);
 313                         $firstInList = $this->counter == 1;
 314                         $s = $this->historyLine( $this->lastRow, $row, $this->counter++,
 315                                 $this->title->getNotificationTimestamp(), $latest, $firstInList );
 316                 } else {
 317                         $s = '';
 318                 }
 319                 $this->lastRow = $row;
 320                 return $s;
 321         }
 322
 323         /**
 324          * Creates begin of history list with a submit button
 325          *
 326          * @return string HTML output
 327          */
 328         function getStartBody() {
 329                 global $wgScript, $wgEnableHtmlDiff, $wgUser, $wgOut;
 330                 $this->lastRow = false;
 331                 $this->counter = 1;
 332                 $this->oldIdChecked = 0;
 333
 334                 $wgOut->wrapWikiMsg( "<div class='mw-history-legend'>\n$1</div>", 'histlegend' );
 335                 $s = Xml::openElement( 'form', array( 'action' => $wgScript,
 336                         'id' => 'mw-history-compare' ) ) . "\n";
 337                 $s .= Xml::hidden( 'title', $this->title->getPrefixedDbKey() ) . "\n";
 338
 339                 $this->buttons = '<div>';
 340                 if( $wgUser->isAllowed('deleterevision') ) {
 341                         $this->buttons .= Xml::element( 'button',
 342                                 array(
 343                                         'type' => 'submit',
 344                                         'name' => 'action',
 345                                         'value' => 'revisiondelete',
 346                                         'style' => 'float: right',
 347                                 ),
 348                                 wfMsg( 'showhideselectedversions' )
 349                         ) . "\n";
 350                 }
 351                 if( $wgEnableHtmlDiff ) {
 352                         $this->buttons .= Xml::element( 'button',
 353                                 array(
 354                                         'type'      => 'submit',
 355                                         'name'      => 'htmldiff',
 356                                         'value'     => '1',
 357                                         'class'     => 'historysubmit',
 358                                         'accesskey' => wfMsg( 'accesskey-visualcomparison' ),
 359                                         'title'     => wfMsg( 'tooltip-compareselectedversions' ),
 360                                 ),
 361                                 wfMsg( 'visualcomparison')
 362                         ) . "\n";
 363                         $this->buttons .= $this->submitButton( wfMsg( 'wikicodecomparison'),
 364                                 array(
 365                                         'class'     => 'historysubmit',
 366                                         'accesskey' => wfMsg( 'accesskey-compareselectedversions' ),
 367                                         'title'     => wfMsg( 'tooltip-compareselectedversions' ),
 368                                 )
 369                         ) . "\n";
 370                 } else {
 371                         $this->buttons .= $this->submitButton( wfMsg( 'compareselectedversions'),
 372                                 array(
 373                                         'class'     => 'historysubmit',
 374                                         'accesskey' => wfMsg( 'accesskey-compareselectedversions' ),
 375                                         'title'     => wfMsg( 'tooltip-compareselectedversions' ),
 376                                 )
 377                         ) . "\n";
 378                 }
 379                 $this->buttons .= '</div>';
 380                 $s .= $this->buttons . '<ul id="pagehistory">' . "\n";
 381                 return $s;
 382         }
 383
 384         function getEndBody() {
 385                 if( $this->lastRow ) {
 386                         $latest = $this->counter == 1 && $this->mIsFirst;
 387                         $firstInList = $this->counter == 1;
 388                         if( $this->mIsBackwards ) {
 389                                 # Next row is unknown, but for UI reasons, probably exists if an offset has been specified
 390                                 if( $this->mOffset == '' ) {
 391                                         $next = null;
 392                                 } else {
 393                                         $next = 'unknown';
 394                                 }
 395                         } else {
 396                                 # The next row is the past-the-end row
 397                                 $next = $this->mPastTheEndRow;
 398                         }
 399                         $s = $this->historyLine( $this->lastRow, $next, $this->counter++,
 400                                 $this->title->getNotificationTimestamp(), $latest, $firstInList );
 401                 } else {
 402                         $s = '';
 403                 }
 404                 $s .= "</ul>\n";
 405                 $s .= $this->buttons;
 406                 $s .= '</form>';
 407                 return $s;
 408         }
 409
 410         /**
 411          * Creates a submit button
 412          *
 413          * @param array $attributes attributes
 414          * @return string HTML output for the submit button
 415          */
 416         function submitButton($message, $attributes = array() ) {
 417                 # Disable submit button if history has 1 revision only
 418                 if( $this->getNumRows() > 1 ) {
 419                         return Xml::submitButton( $message , $attributes );
 420                 } else {
 421                         return '';
 422                 }
 423         }
 424
 425         /**
 426          * Returns a row from the history printout.
 427          *
 428          * @todo document some more, and maybe clean up the code (some params redundant?)
 429          *
 430          * @param Row $row The database row corresponding to the previous line.
 431          * @param mixed $next The database row corresponding to the next line.
 432          * @param int $counter Apparently a counter of what row number we're at, counted from the top row = 1.
 433          * @param $notificationtimestamp
 434          * @param bool $latest Whether this row corresponds to the page's latest revision.
 435          * @param bool $firstInList Whether this row corresponds to the first displayed on this history page.
 436          * @return string HTML output for the row
 437          */
 438         function historyLine( $row, $next, $counter = '', $notificationtimestamp = false,
 439                 $latest = false, $firstInList = false )
 440         {
 441                 global $wgUser, $wgLang;
 442                 $rev = new Revision( $row );
 443                 $rev->setTitle( $this->title );
 444
 445                 $curlink = $this->curLink( $rev, $latest );
 446                 $lastlink = $this->lastLink( $rev, $next, $counter );
 447                 $diffButtons = $this->diffButtons( $rev, $firstInList, $counter );
 448                 $link = $this->revLink( $rev );
 449                 $classes = array();
 450
 451                 $s = "($curlink) ($lastlink) $diffButtons";
 452
 453                 if( $wgUser->isAllowed( 'deleterevision' ) ) {
 454                         // If revision was hidden from sysops
 455                         if( !$rev->userCan( Revision::DELETED_RESTRICTED ) ) {
 456                                 $del = Xml::check( 'deleterevisions', false, array('disabled' => 'disabled') );
 457                         // Otherwise, show the link...
 458                         } else {
 459                                 $id = $rev->getId();
 460                                 $del = Xml::check( 'showhiderevisions', false, array( 'name' => "ids[$id]" ) );
 461                         }
 462                         $s .= " $del ";
 463                 }
 464
 465                 $s .= " $link";
 466                 $s .= " <span class='history-user'>" . $this->getSkin()->revUserTools( $rev, true ) . "</span>";
 467
 468                 if( $rev->isMinor() ) {
 469                         $s .= ' ' . ChangesList::flag( 'minor' );
 470                 }
 471
 472                 if( !is_null( $size = $rev->getSize() ) && !$rev->isDeleted( Revision::DELETED_TEXT ) ) {
 473                         $s .= ' ' . $this->getSkin()->formatRevisionSize( $size );
 474                 }
 475
 476                 $s .= $this->getSkin()->revComment( $rev, false, true );
 477
 478                 if( $notificationtimestamp && ($row->rev_timestamp >= $notificationtimestamp) ) {
 479                         $s .= ' <span class="updatedmarker">' .  wfMsgHtml( 'updatedmarker' ) . '</span>';
 480                 }
 481
 482                 $tools = array();
 483
 484                 # Rollback and undo links
 485                 if( !is_null( $next ) && is_object( $next ) ) {
 486                         if( $latest && $this->title->userCan( 'rollback' ) && $this->title->userCan( 'edit' ) ) {
 487                                 $tools[] = '<span class="mw-rollback-link">'.
 488                                         $this->getSkin()->buildRollbackLink( $rev ).'</span>';
 489                         }
 490
 491                         if( $this->title->quickUserCan( 'edit' )
 492                                 && !$rev->isDeleted( Revision::DELETED_TEXT )
 493                                 && !$next->rev_deleted & Revision::DELETED_TEXT )
 494                         {
 495                                 # Create undo tooltip for the first (=latest) line only
 496                                 $undoTooltip = $latest
 497                                         ? array( 'title' => wfMsg( 'tooltip-undo' ) )
 498                                         : array();
 499                                 $undolink = $this->getSkin()->link(
 500                                         $this->title,
 501                                         wfMsgHtml( 'editundo' ),
 502                                         $undoTooltip,
 503                                         array( 'action' => 'edit', 'undoafter' => $next->rev_id, 'undo' => $rev->getId() ),
 504                                         array( 'known', 'noclasses' )
 505                                 );
 506                                 $tools[] = "<span class=\"mw-history-undo\">{$undolink}</span>";
 507                         }
 508                 }
 509
 510                 if( $tools ) {
 511                         $s .= ' (' . $wgLang->pipeList( $tools ) . ')';
 512                 }
 513
 514                 # Tags
 515                 list($tagSummary, $newClasses) = ChangeTags::formatSummaryRow( $row->ts_tags, 'history' );
 516                 $classes = array_merge( $classes, $newClasses );
 517                 $s .= " $tagSummary";
 518
 519                 wfRunHooks( 'PageHistoryLineEnding', array( $this, &$row , &$s ) );
 520
 521                 $attribs = array();
 522                 if ( $classes ) {
 523                         $attribs['class'] = implode( ' ', $classes );
 524                 }
 525
 526                 return Xml::tags( 'li', $attribs, $s ) . "\n";
 527         }
 528
 529         /**
 530          * Create a link to view this revision of the page
 531          * @param Revision $rev
 532          * @returns string
 533          */
 534         function revLink( $rev ) {
 535                 global $wgLang;
 536                 $date = $wgLang->timeanddate( wfTimestamp(TS_MW, $rev->getTimestamp()), true );
 537                 $date = htmlspecialchars( $date );
 538                 if( !$rev->isDeleted( Revision::DELETED_TEXT ) ) {
 539                         $link = $this->getSkin()->link(
 540                                 $this->title,
 541                                 $date,
 542                                 array(),
 543                                 array( 'oldid' => $rev->getId() ),
 544                                 array( 'known', 'noclasses' )
 545                         );
 546                 } else {
 547                         $link = "<span class=\"history-deleted\">$date</span>";
 548                 }
 549                 return $link;
 550         }
 551
 552         /**
 553          * Create a diff-to-current link for this revision for this page
 554          * @param Revision $rev
 555          * @param Bool $latest, this is the latest revision of the page?
 556          * @returns string
 557          */
 558         function curLink( $rev, $latest ) {
 559                 $cur = $this->historyPage->message['cur'];
 560                 if( $latest || !$rev->userCan( Revision::DELETED_TEXT ) ) {
 561                         return $cur;
 562                 } else {
 563                         return $this->getSkin()->link(
 564                                 $this->title,
 565                                 $cur,
 566                                 array(),
 567                                 array(
 568                                         'diff' => $this->title->getLatestRevID(),
 569                                         'oldid' => $rev->getId()
 570                                 ),
 571                                 array( 'known', 'noclasses' )
 572                         );
 573                 }
 574         }
 575
 576         /**
 577          * Create a diff-to-previous link for this revision for this page.
 578          * @param Revision $prevRev, the previous revision
 579          * @param mixed $next, the newer revision
 580          * @param int $counter, what row on the history list this is
 581          * @returns string
 582          */
 583         function lastLink( $prevRev, $next, $counter ) {
 584                 $last = $this->historyPage->message['last'];
 585                 # $next may either be a Row, null, or "unkown"
 586                 $nextRev = is_object($next) ? new Revision( $next ) : $next;
 587                 if( is_null($next) ) {
 588                         # Probably no next row
 589                         return $last;
 590                 } elseif( $next === 'unknown' ) {
 591                         # Next row probably exists but is unknown, use an oldid=prev link
 592                         return $this->getSkin()->link(
 593                                 $this->title,
 594                                 $last,
 595                                 array(),
 596                                 array(
 597                                         'diff' => $prevRev->getId(),
 598                                         'oldid' => 'prev'
 599                                 ),
 600                                 array( 'known', 'noclasses' )
 601                         );
 602                 } elseif( !$prevRev->userCan(Revision::DELETED_TEXT) || !$nextRev->userCan(Revision::DELETED_TEXT) ) {
 603                         return $last;
 604                 } else {
 605                         return $this->getSkin()->link(
 606                                 $this->title,
 607                                 $last,
 608                                 array(),
 609                                 array(
 610                                         'diff' => $prevRev->getId(),
 611                                         'oldid' => $next->rev_id
 612                                 ),
 613                                 array( 'known', 'noclasses' )
 614                         );
 615                 }
 616         }
 617
 618         /**
 619          * Create radio buttons for page history
 620          *
 621          * @param object $rev Revision
 622          * @param bool $firstInList Is this version the first one?
 623          * @param int $counter A counter of what row number we're at, counted from the top row = 1.
 624          * @return string HTML output for the radio buttons
 625          */
 626         function diffButtons( $rev, $firstInList, $counter ) {
 627                 if( $this->getNumRows() > 1 ) {
 628                         $id = $rev->getId();
 629                         $radio = array( 'type'  => 'radio', 'value' => $id );
 630                         /** @todo: move title texts to javascript */
 631                         if( $firstInList ) {
 632                                 $first = Xml::element( 'input',
 633                                         array_merge( $radio, array(
 634                                                 'style' => 'visibility:hidden',
 635                                                 'name'  => 'oldid',
 636                                                 'id' => 'mw-oldid-null' ) )
 637                                 );
 638                                 $checkmark = array( 'checked' => 'checked' );
 639                         } else {
 640                                 # Check visibility of old revisions
 641                                 if( !$rev->userCan( Revision::DELETED_TEXT ) ) {
 642                                         $radio['disabled'] = 'disabled';
 643                                         $checkmark = array(); // We will check the next possible one
 644                                 } else if( $counter == 2 || !$this->oldIdChecked ) {
 645                                         $checkmark = array( 'checked' => 'checked' );
 646                                         $this->oldIdChecked = $id;
 647                                 } else {
 648                                         $checkmark = array();
 649                                 }
 650                                 $first = Xml::element( 'input',
 651                                         array_merge( $radio, $checkmark, array(
 652                                                 'name'  => 'oldid',
 653                                                 'id' => "mw-oldid-$id" ) ) );
 654                                 $checkmark = array();
 655                         }
 656                         $second = Xml::element( 'input',
 657                                 array_merge( $radio, $checkmark, array(
 658                                         'name'  => 'diff',
 659                                         'id' => "mw-diff-$id" ) ) );
 660                         return $first . $second;
 661                 } else {
 662                         return '';
 663                 }
 664         }
 665 }
 666
 667 /**
 668  * Backwards-compatibility aliases
 669  */
 670 class PageHistory extends HistoryPage {}
 671 class PageHistoryPager extends HistoryPager {}
 672