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