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