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         /** Shortcut to the user Skin object. */
  27         private $skin;
  28
  29         /**
  30          * Construct a new HistoryPage.
  31          *
  32          * @param $article Article
  33          */
  34         function __construct( $article ) {
  35                 global $wgUser;
  36                 $this->article = $article;
  37                 $this->title = $article->getTitle();
  38                 $this->skin = $wgUser->getSkin();
  39                 $this->preCacheMessages();
  40         }
  41
  42         /** Get the Article object we are working on. */
  43         public function getArticle() {
  44                 return $this->article;
  45         }
  46
  47         /** Get the Title object. */
  48         public function getTitle() {
  49                 return $this->title;
  50         }
  51
  52         /**
  53          * As we use the same small set of messages in various methods and that
  54          * they are called often, we call them once and save them in $this->message
  55          */
  56         private function preCacheMessages() {
  57                 // Precache various messages
  58                 if ( !isset( $this->message ) ) {
  59                         $msgs = array( 'cur', 'last', 'pipe-separator' );
  60                         foreach ( $msgs as $msg ) {
  61                                 $this->message[$msg] = wfMsgExt( $msg, array( 'escapenoentities' ) );
  62                         }
  63                 }
  64         }
  65
  66         /**
  67          * Print the history page for an article.
  68          * @return nothing
  69          */
  70         function history() {
  71                 global $wgOut, $wgRequest, $wgScript;
  72
  73                 /**
  74                  * Allow client caching.
  75                  */
  76                 if ( $wgOut->checkLastModified( $this->article->getTouched() ) )
  77                         return; // Client cache fresh and headers sent, nothing more to do.
  78
  79                 wfProfileIn( __METHOD__ );
  80
  81                 // Setup page variables.
  82                 $wgOut->setPageTitle( wfMsg( 'history-title', $this->title->getPrefixedText() ) );
  83                 $wgOut->setPageTitleActionText( wfMsg( 'history_short' ) );
  84                 $wgOut->setArticleFlag( false );
  85                 $wgOut->setArticleRelated( true );
  86                 $wgOut->setRobotPolicy( 'noindex,nofollow' );
  87                 $wgOut->setSyndicated( true );
  88                 $wgOut->setFeedAppendQuery( 'action=history' );
  89                 $wgOut->addModules( array( 'mediawiki.legacy.history', 'mediawiki.action.history' ) );
  90
  91                 // Creation of a subtitle link pointing to [[Special:Log]]
  92                 $logPage = SpecialPage::getTitleFor( 'Log' );
  93                 $logLink = $this->skin->link(
  94                         $logPage,
  95                         wfMsgHtml( 'viewpagelogs' ),
  96                         array(),
  97                         array( 'page' => $this->title->getPrefixedText() ),
  98                         array( 'known', 'noclasses' )
  99                 );
 100                 $wgOut->setSubtitle( $logLink );
 101
 102                 // Handle atom/RSS feeds.
 103                 $feedType = $wgRequest->getVal( 'feed' );
 104                 if ( $feedType ) {
 105                         wfProfileOut( __METHOD__ );
 106                         return $this->feed( $feedType );
 107                 }
 108
 109                 // Fail nicely if article doesn't exist.
 110                 if ( !$this->title->exists() ) {
 111                         $wgOut->addWikiMsg( 'nohistory' );
 112                         # show deletion/move log if there is an entry
 113                         LogEventsList::showLogExtract(
 114                                 $wgOut,
 115                                 array( 'delete', 'move' ),
 116                                 $this->title->getPrefixedText(),
 117                                 '',
 118                                 array(  'lim' => 10,
 119                                         'conds' => array( "log_action != 'revision'" ),
 120                                         'showIfEmpty' => false,
 121                                         'msgKey' => array( 'moveddeleted-notice' )
 122                                 )
 123                         );
 124                         wfProfileOut( __METHOD__ );
 125                         return;
 126                 }
 127
 128                 /**
 129                  * Add date selector to quickly get to a certain time
 130                  */
 131                 $year        = $wgRequest->getInt( 'year' );
 132                 $month       = $wgRequest->getInt( 'month' );
 133                 $tagFilter   = $wgRequest->getVal( 'tagfilter' );
 134                 $tagSelector = ChangeTags::buildTagFilterSelector( $tagFilter );
 135
 136                 /**
 137                  * Option to show only revisions that have been (partially) hidden via RevisionDelete
 138                  */
 139                 if ( $wgRequest->getBool( 'deleted' ) ) {
 140                         $conds = array( "rev_deleted != '0'" );
 141                 } else {
 142                         $conds = array();
 143                 }
 144                 $checkDeleted = Xml::checkLabel( wfMsg( 'history-show-deleted' ),
 145                         'deleted', 'mw-show-deleted-only', $wgRequest->getBool( 'deleted' ) ) . "\n";
 146
 147                 // Add the general form
 148                 $action = htmlspecialchars( $wgScript );
 149                 $wgOut->addHTML(
 150                         "<form action=\"$action\" method=\"get\" id=\"mw-history-searchform\">" .
 151                         Xml::fieldset(
 152                                 wfMsg( 'history-fieldset-title' ),
 153                                 false,
 154                                 array( 'id' => 'mw-history-search' )
 155                         ) .
 156                         Html::hidden( 'title', $this->title->getPrefixedDBKey() ) . "\n" .
 157                         Html::hidden( 'action', 'history' ) . "\n" .
 158                         Xml::dateMenu( $year, $month ) . '&#160;' .
 159                         ( $tagSelector ? ( implode( '&#160;', $tagSelector ) . '&#160;' ) : '' ) .
 160                         $checkDeleted .
 161                         Xml::submitButton( wfMsg( 'allpagessubmit' ) ) . "\n" .
 162                         '</fieldset></form>'
 163                 );
 164
 165                 wfRunHooks( 'PageHistoryBeforeList', array( &$this->article ) );
 166
 167                 // Create and output the list.
 168                 $pager = new HistoryPager( $this, $year, $month, $tagFilter, $conds );
 169                 $wgOut->addHTML(
 170                         $pager->getNavigationBar() .
 171                         $pager->getBody() .
 172                         $pager->getNavigationBar()
 173                 );
 174                 $wgOut->preventClickjacking( $pager->getPreventClickjacking() );
 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          * @param $limit Integer: the limit number of revisions to get
 185          * @param $offset Integer
 186          * @param $direction Integer: either HistoryPage::DIR_PREV or HistoryPage::DIR_NEXT
 187          * @return ResultWrapper
 188          */
 189         function fetchRevisions( $limit, $offset, $direction ) {
 190                 $dbr = wfGetDB( DB_SLAVE );
 191
 192                 if ( $direction == HistoryPage::DIR_PREV ) {
 193                         list( $dirs, $oper ) = array( "ASC", ">=" );
 194                 } else { /* $direction == HistoryPage::DIR_NEXT */
 195                         list( $dirs, $oper ) = array( "DESC", "<=" );
 196                 }
 197
 198                 if ( $offset ) {
 199                         $offsets = array( "rev_timestamp $oper '$offset'" );
 200                 } else {
 201                         $offsets = array();
 202                 }
 203
 204                 $page_id = $this->title->getArticleID();
 205
 206                 return $dbr->select( 'revision',
 207                         Revision::selectFields(),
 208                         array_merge( array( "rev_page=$page_id" ), $offsets ),
 209                         __METHOD__,
 210                         array( 'ORDER BY' => "rev_timestamp $dirs",
 211                                 'USE INDEX' => 'page_timestamp', 'LIMIT' => $limit )
 212                 );
 213         }
 214
 215         /**
 216          * Output a subscription feed listing recent edits to this page.
 217          *
 218          * @param $type String: feed type
 219          */
 220         function feed( $type ) {
 221                 global $wgFeedClasses, $wgRequest, $wgFeedLimit;
 222                 if ( !FeedUtils::checkFeedOutput( $type ) ) {
 223                         return;
 224                 }
 225
 226                 $feed = new $wgFeedClasses[$type](
 227                         $this->title->getPrefixedText() . ' - ' .
 228                         wfMsgForContent( 'history-feed-title' ),
 229                         wfMsgForContent( 'history-feed-description' ),
 230                         $this->title->getFullUrl( 'action=history' )
 231                 );
 232
 233                 // Get a limit on number of feed entries. Provide a sane default
 234                 // of 10 if none is defined (but limit to $wgFeedLimit max)
 235                 $limit = $wgRequest->getInt( 'limit', 10 );
 236                 if ( $limit > $wgFeedLimit || $limit < 1 ) {
 237                         $limit = 10;
 238                 }
 239                 $items = $this->fetchRevisions( $limit, 0, HistoryPage::DIR_NEXT );
 240
 241                 // Generate feed elements enclosed between header and footer.
 242                 $feed->outHeader();
 243                 if ( $items ) {
 244                         foreach ( $items as $row ) {
 245                                 $feed->outItem( $this->feedItem( $row ) );
 246                         }
 247                 } else {
 248                         $feed->outItem( $this->feedEmpty() );
 249                 }
 250                 $feed->outFooter();
 251         }
 252
 253         function feedEmpty() {
 254                 global $wgOut;
 255                 return new FeedItem(
 256                         wfMsgForContent( 'nohistory' ),
 257                         $wgOut->parse( wfMsgForContent( 'history-feed-empty' ) ),
 258                         $this->title->getFullUrl(),
 259                         wfTimestamp( TS_MW ),
 260                         '',
 261                         $this->title->getTalkPage()->getFullUrl()
 262                 );
 263         }
 264
 265         /**
 266          * Generate a FeedItem object from a given revision table row
 267          * Borrows Recent Changes' feed generation functions for formatting;
 268          * includes a diff to the previous revision (if any).
 269          *
 270          * @param $row Object: database row
 271          * @return FeedItem
 272          */
 273         function feedItem( $row ) {
 274                 $rev = new Revision( $row );
 275                 $rev->setTitle( $this->title );
 276                 $text = FeedUtils::formatDiffRow(
 277                         $this->title,
 278                         $this->title->getPreviousRevisionID( $rev->getId() ),
 279                         $rev->getId(),
 280                         $rev->getTimestamp(),
 281                         $rev->getComment()
 282                 );
 283                 if ( $rev->getComment() == '' ) {
 284                         global $wgContLang;
 285                         $title = wfMsgForContent( 'history-feed-item-nocomment',
 286                                 $rev->getUserText(),
 287                                 $wgContLang->timeanddate( $rev->getTimestamp() ),
 288                                 $wgContLang->date( $rev->getTimestamp() ),
 289                                 $wgContLang->time( $rev->getTimestamp() )
 290                         );
 291                 } else {
 292                         $title = $rev->getUserText() .
 293                         wfMsgForContent( 'colon-separator' ) .
 294                         FeedItem::stripComment( $rev->getComment() );
 295                 }
 296                 return new FeedItem(
 297                         $title,
 298                         $text,
 299                         $this->title->getFullUrl( 'diff=' . $rev->getId() . '&oldid=prev' ),
 300                         $rev->getTimestamp(),
 301                         $rev->getUserText(),
 302                         $this->title->getTalkPage()->getFullUrl()
 303                 );
 304         }
 305 }
 306
 307 /**
 308  * @ingroup Pager
 309  */
 310 class HistoryPager extends ReverseChronologicalPager {
 311         public $lastRow = false, $counter, $historyPage, $title, $buttons, $conds;
 312         protected $oldIdChecked;
 313         protected $preventClickjacking = false;
 314
 315         function __construct( $historyPage, $year = '', $month = '', $tagFilter = '', $conds = array() ) {
 316                 parent::__construct();
 317                 $this->historyPage = $historyPage;
 318                 $this->title = $this->historyPage->getTitle();
 319                 $this->tagFilter = $tagFilter;
 320                 $this->getDateCond( $year, $month );
 321                 $this->conds = $conds;
 322         }
 323
 324         // For hook compatibility...
 325         function getArticle() {
 326                 return $this->historyPage->getArticle();
 327         }
 328
 329         function getSqlComment() {
 330                 if ( $this->conds ) {
 331                         return 'history page filtered'; // potentially slow, see CR r58153
 332                 } else {
 333                         return 'history page unfiltered';
 334                 }
 335         }
 336
 337         function getQueryInfo() {
 338                 $queryInfo = array(
 339                         'tables'  => array( 'revision' ),
 340                         'fields'  => Revision::selectFields(),
 341                         'conds'   => array_merge(
 342                                 array( 'rev_page' => $this->historyPage->getTitle()->getArticleID() ),
 343                                 $this->conds ),
 344                         'options' => array( 'USE INDEX' => array( 'revision' => 'page_timestamp' ) ),
 345                         'join_conds' => array( 'tag_summary' => array( 'LEFT JOIN', 'ts_rev_id=rev_id' ) ),
 346                 );
 347                 ChangeTags::modifyDisplayQuery(
 348                         $queryInfo['tables'],
 349                         $queryInfo['fields'],
 350                         $queryInfo['conds'],
 351                         $queryInfo['join_conds'],
 352                         $queryInfo['options'],
 353                         $this->tagFilter
 354                 );
 355                 wfRunHooks( 'PageHistoryPager::getQueryInfo', array( &$this, &$queryInfo ) );
 356                 return $queryInfo;
 357         }
 358
 359         function getIndexField() {
 360                 return 'rev_timestamp';
 361         }
 362
 363         function formatRow( $row ) {
 364                 if ( $this->lastRow ) {
 365                         $latest = ( $this->counter == 1 && $this->mIsFirst );
 366                         $firstInList = $this->counter == 1;
 367                         $this->counter++;
 368                         $s = $this->historyLine( $this->lastRow, $row,
 369                                 $this->title->getNotificationTimestamp(), $latest, $firstInList );
 370                 } else {
 371                         $s = '';
 372                 }
 373                 $this->lastRow = $row;
 374                 return $s;
 375         }
 376
 377         /**
 378          * Creates begin of history list with a submit button
 379          *
 380          * @return string HTML output
 381          */
 382         function getStartBody() {
 383                 global $wgScript, $wgUser, $wgOut;
 384                 $this->lastRow = false;
 385                 $this->counter = 1;
 386                 $this->oldIdChecked = 0;
 387
 388                 $wgOut->wrapWikiMsg( "<div class='mw-history-legend'>\n$1\n</div>", 'histlegend' );
 389                 $s = Html::openElement( 'form', array( 'action' => $wgScript,
 390                         'id' => 'mw-history-compare' ) ) . "\n";
 391                 $s .= Html::hidden( 'title', $this->title->getPrefixedDbKey() ) . "\n";
 392                 $s .= Html::hidden( 'action', 'historysubmit' ) . "\n";
 393
 394                 $s .= '<div>' . $this->submitButton( wfMsg( 'compareselectedversions' ),
 395                         array( 'class' => 'historysubmit' ) ) . "\n";
 396
 397                 $this->buttons = '<div>';
 398                 $this->buttons .= $this->submitButton( wfMsg( 'compareselectedversions' ),
 399                         array( 'class' => 'historysubmit' )
 400                                 + Linker::tooltipAndAccesskeyAttribs( 'compareselectedversions' )
 401                 ) . "\n";
 402
 403                 if ( $wgUser->isAllowed( 'deleterevision' ) ) {
 404                         $s .= $this->getRevisionButton( 'revisiondelete', 'showhideselectedversions' );
 405                 }
 406                 $this->buttons .= '</div>';
 407                 $s .= '</div><ul id="pagehistory">' . "\n";
 408                 return $s;
 409         }
 410
 411         private function getRevisionButton( $name, $msg ) {
 412                 $this->preventClickjacking();
 413                 # Note bug #20966, <button> is non-standard in IE<8
 414                 $element = Html::element( 'button',
 415                         array(
 416                                 'type' => 'submit',
 417                                 'name' => $name,
 418                                 'value' => '1',
 419                                 'class' => "mw-history-$name-button mw-float-end",
 420                         ),
 421                         wfMsg( $msg )
 422                 ) . "\n";
 423                 $this->buttons .= $element;
 424                 return $element;
 425         }
 426
 427         function getEndBody() {
 428                 if ( $this->lastRow ) {
 429                         $latest = $this->counter == 1 && $this->mIsFirst;
 430                         $firstInList = $this->counter == 1;
 431                         if ( $this->mIsBackwards ) {
 432                                 # Next row is unknown, but for UI reasons, probably exists if an offset has been specified
 433                                 if ( $this->mOffset == '' ) {
 434                                         $next = null;
 435                                 } else {
 436                                         $next = 'unknown';
 437                                 }
 438                         } else {
 439                                 # The next row is the past-the-end row
 440                                 $next = $this->mPastTheEndRow;
 441                         }
 442                         $this->counter++;
 443                         $s = $this->historyLine( $this->lastRow, $next,
 444                                 $this->title->getNotificationTimestamp(), $latest, $firstInList );
 445                 } else {
 446                         $s = '';
 447                 }
 448                 $s .= "</ul>\n";
 449                 # Add second buttons only if there is more than one rev
 450                 if ( $this->getNumRows() > 2 ) {
 451                         $s .= $this->buttons;
 452                 }
 453                 $s .= '</form>';
 454                 return $s;
 455         }
 456
 457         /**
 458          * Creates a submit button
 459          *
 460          * @param $message String: text of the submit button, will be escaped
 461          * @param $attributes Array: attributes
 462          * @return String: HTML output for the submit button
 463          */
 464         function submitButton( $message, $attributes = array() ) {
 465                 # Disable submit button if history has 1 revision only
 466                 if ( $this->getNumRows() > 1 ) {
 467                         return Xml::submitButton( $message , $attributes );
 468                 } else {
 469                         return '';
 470                 }
 471         }
 472
 473         /**
 474          * Returns a row from the history printout.
 475          *
 476          * @todo document some more, and maybe clean up the code (some params redundant?)
 477          *
 478          * @param $row Object: the database row corresponding to the previous line.
 479          * @param $next Mixed: the database row corresponding to the next line.
 480          * @param $notificationtimestamp
 481          * @param $latest Boolean: whether this row corresponds to the page's latest revision.
 482          * @param $firstInList Boolean: whether this row corresponds to the first displayed on this history page.
 483          * @return String: HTML output for the row
 484          */
 485         function historyLine( $row, $next, $notificationtimestamp = false,
 486                 $latest = false, $firstInList = false )
 487         {
 488                 global $wgUser, $wgLang;
 489                 $rev = new Revision( $row );
 490                 $rev->setTitle( $this->title );
 491
 492                 $curlink = $this->curLink( $rev, $latest );
 493                 $lastlink = $this->lastLink( $rev, $next );
 494                 $diffButtons = $this->diffButtons( $rev, $firstInList );
 495                 $histLinks = Html::rawElement(
 496                                 'span',
 497                                 array( 'class' => 'mw-history-histlinks' ),
 498                                 '(' . $curlink . $this->historyPage->message['pipe-separator'] . $lastlink . ') '
 499                 );
 500                 $s = $histLinks . $diffButtons;
 501
 502                 $link = $this->revLink( $rev );
 503                 $classes = array();
 504
 505                 $del = '';
 506                 // Show checkboxes for each revision
 507                 if ( $wgUser->isAllowed( 'deleterevision' ) ) {
 508                         $this->preventClickjacking();
 509                         // If revision was hidden from sysops, disable the checkbox
 510                         if ( !$rev->userCan( Revision::DELETED_RESTRICTED ) ) {
 511                                 $del = Xml::check( 'deleterevisions', false, array( 'disabled' => 'disabled' ) );
 512                         // Otherwise, enable the checkbox...
 513                         } else {
 514                                 $del = Xml::check( 'showhiderevisions', false,
 515                                         array( 'name' => 'ids[' . $rev->getId() . ']' ) );
 516                         }
 517                 // User can only view deleted revisions...
 518                 } elseif ( $rev->getVisibility() && $wgUser->isAllowed( 'deletedhistory' ) ) {
 519                         // If revision was hidden from sysops, disable the link
 520                         if ( !$rev->userCan( Revision::DELETED_RESTRICTED ) ) {
 521                                 $cdel = $this->getSkin()->revDeleteLinkDisabled( false );
 522                         // Otherwise, show the link...
 523                         } else {
 524                                 $query = array( 'type' => 'revision',
 525                                         'target' => $this->title->getPrefixedDbkey(), 'ids' => $rev->getId() );
 526                                 $del .= $this->getSkin()->revDeleteLink( $query,
 527                                         $rev->isDeleted( Revision::DELETED_RESTRICTED ), false );
 528                         }
 529                 }
 530                 if ( $del ) {
 531                         $s .= " $del ";
 532                 }
 533
 534                 $dirmark = $wgLang->getDirMark();
 535
 536                 $s .= " $link";
 537                 $s .= $dirmark;
 538                 $s .= " <span class='history-user'>" .
 539                         $this->getSkin()->revUserTools( $rev, true ) . "</span>";
 540                 $s .= $dirmark;
 541
 542                 if ( $rev->isMinor() ) {
 543                         $s .= ' ' . ChangesList::flag( 'minor' );
 544                 }
 545
 546                 if ( !is_null( $size = $rev->getSize() ) && !$rev->isDeleted( Revision::DELETED_TEXT ) ) {
 547                         $s .= ' ' . $this->getSkin()->formatRevisionSize( $size );
 548                 }
 549
 550                 $s .= $this->getSkin()->revComment( $rev, false, true );
 551
 552                 if ( $notificationtimestamp && ( $row->rev_timestamp >= $notificationtimestamp ) ) {
 553                         $s .= ' <span class="updatedmarker">' .  wfMsgHtml( 'updatedmarker' ) . '</span>';
 554                 }
 555
 556                 $tools = array();
 557
 558                 # Rollback and undo links
 559                 if ( !is_null( $next ) && is_object( $next ) ) {
 560                         if ( $latest && $this->title->userCan( 'rollback' ) && $this->title->userCan( 'edit' ) ) {
 561                                 $this->preventClickjacking();
 562                                 $tools[] = '<span class="mw-rollback-link">' .
 563                                         $this->getSkin()->buildRollbackLink( $rev ) . '</span>';
 564                         }
 565
 566                         if ( $this->title->quickUserCan( 'edit' )
 567                                 && !$rev->isDeleted( Revision::DELETED_TEXT )
 568                                 && !$next->rev_deleted & Revision::DELETED_TEXT )
 569                         {
 570                                 # Create undo tooltip for the first (=latest) line only
 571                                 $undoTooltip = $latest
 572                                         ? array( 'title' => wfMsg( 'tooltip-undo' ) )
 573                                         : array();
 574                                 $undolink = $this->getSkin()->link(
 575                                         $this->title,
 576                                         wfMsgHtml( 'editundo' ),
 577                                         $undoTooltip,
 578                                         array(
 579                                                 'action' => 'edit',
 580                                                 'undoafter' => $next->rev_id,
 581                                                 'undo' => $rev->getId()
 582                                         ),
 583                                         array( 'known', 'noclasses' )
 584                                 );
 585                                 $tools[] = "<span class=\"mw-history-undo\">{$undolink}</span>";
 586                         }
 587                 }
 588
 589                 if ( $tools ) {
 590                         $s .= ' (' . $wgLang->pipeList( $tools ) . ')';
 591                 }
 592
 593                 # Tags
 594                 list( $tagSummary, $newClasses ) = ChangeTags::formatSummaryRow( $row->ts_tags, 'history' );
 595                 $classes = array_merge( $classes, $newClasses );
 596                 $s .= " $tagSummary";
 597
 598                 wfRunHooks( 'PageHistoryLineEnding', array( $this, &$row , &$s, &$classes ) );
 599
 600                 $attribs = array();
 601                 if ( $classes ) {
 602                         $attribs['class'] = implode( ' ', $classes );
 603                 }
 604
 605                 return Xml::tags( 'li', $attribs, $s ) . "\n";
 606         }
 607
 608         /**
 609          * Create a link to view this revision of the page
 610          *
 611          * @param $rev Revision
 612          * @return String
 613          */
 614         function revLink( $rev ) {
 615                 global $wgLang;
 616                 $date = $wgLang->timeanddate( wfTimestamp( TS_MW, $rev->getTimestamp() ), true );
 617                 $date = htmlspecialchars( $date );
 618                 if ( $rev->userCan( Revision::DELETED_TEXT ) ) {
 619                         $link = $this->getSkin()->link(
 620                                 $this->title,
 621                                 $date,
 622                                 array(),
 623                                 array( 'oldid' => $rev->getId() ),
 624                                 array( 'known', 'noclasses' )
 625                         );
 626                 } else {
 627                         $link = $date;
 628                 }
 629                 if ( $rev->isDeleted( Revision::DELETED_TEXT ) ) {
 630                         $link = "<span class=\"history-deleted\">$link</span>";
 631                 }
 632                 return $link;
 633         }
 634
 635         /**
 636          * Create a diff-to-current link for this revision for this page
 637          *
 638          * @param $rev Revision
 639          * @param $latest Boolean: this is the latest revision of the page?
 640          * @return String
 641          */
 642         function curLink( $rev, $latest ) {
 643                 $cur = $this->historyPage->message['cur'];
 644                 if ( $latest || !$rev->userCan( Revision::DELETED_TEXT ) ) {
 645                         return $cur;
 646                 } else {
 647                         return $this->getSkin()->link(
 648                                 $this->title,
 649                                 $cur,
 650                                 array(),
 651                                 array(
 652                                         'diff' => $this->title->getLatestRevID(),
 653                                         'oldid' => $rev->getId()
 654                                 ),
 655                                 array( 'known', 'noclasses' )
 656                         );
 657                 }
 658         }
 659
 660         /**
 661          * Create a diff-to-previous link for this revision for this page.
 662          *
 663          * @param $prevRev Revision: the previous revision
 664          * @param $next Mixed: the newer revision
 665          * @return String
 666          */
 667         function lastLink( $prevRev, $next ) {
 668                 $last = $this->historyPage->message['last'];
 669                 # $next may either be a Row, null, or "unkown"
 670                 $nextRev = is_object( $next ) ? new Revision( $next ) : $next;
 671                 if ( is_null( $next ) ) {
 672                         # Probably no next row
 673                         return $last;
 674                 } elseif ( $next === 'unknown' ) {
 675                         # Next row probably exists but is unknown, use an oldid=prev link
 676                         return $this->getSkin()->link(
 677                                 $this->title,
 678                                 $last,
 679                                 array(),
 680                                 array(
 681                                         'diff' => $prevRev->getId(),
 682                                         'oldid' => 'prev'
 683                                 ),
 684                                 array( 'known', 'noclasses' )
 685                         );
 686                 } elseif ( !$prevRev->userCan( Revision::DELETED_TEXT )
 687                         || !$nextRev->userCan( Revision::DELETED_TEXT ) )
 688                 {
 689                         return $last;
 690                 } else {
 691                         return $this->getSkin()->link(
 692                                 $this->title,
 693                                 $last,
 694                                 array(),
 695                                 array(
 696                                         'diff' => $prevRev->getId(),
 697                                         'oldid' => $next->rev_id
 698                                 ),
 699                                 array( 'known', 'noclasses' )
 700                         );
 701                 }
 702         }
 703
 704         /**
 705          * Create radio buttons for page history
 706          *
 707          * @param $rev Revision object
 708          * @param $firstInList Boolean: is this version the first one?
 709          *
 710          * @return String: HTML output for the radio buttons
 711          */
 712         function diffButtons( $rev, $firstInList ) {
 713                 if ( $this->getNumRows() > 1 ) {
 714                         $id = $rev->getId();
 715                         $radio = array( 'type'  => 'radio', 'value' => $id );
 716                         /** @todo: move title texts to javascript */
 717                         if ( $firstInList ) {
 718                                 $first = Xml::element( 'input',
 719                                         array_merge( $radio, array(
 720                                                 'style' => 'visibility:hidden',
 721                                                 'name'  => 'oldid',
 722                                                 'id' => 'mw-oldid-null' ) )
 723                                 );
 724                                 $checkmark = array( 'checked' => 'checked' );
 725                         } else {
 726                                 # Check visibility of old revisions
 727                                 if ( !$rev->userCan( Revision::DELETED_TEXT ) ) {
 728                                         $radio['disabled'] = 'disabled';
 729                                         $checkmark = array(); // We will check the next possible one
 730                                 } elseif ( !$this->oldIdChecked ) {
 731                                         $checkmark = array( 'checked' => 'checked' );
 732                                         $this->oldIdChecked = $id;
 733                                 } else {
 734                                         $checkmark = array();
 735                                 }
 736                                 $first = Xml::element( 'input',
 737                                         array_merge( $radio, $checkmark, array(
 738                                                 'name'  => 'oldid',
 739                                                 'id' => "mw-oldid-$id" ) ) );
 740                                 $checkmark = array();
 741                         }
 742                         $second = Xml::element( 'input',
 743                                 array_merge( $radio, $checkmark, array(
 744                                         'name'  => 'diff',
 745                                         'id' => "mw-diff-$id" ) ) );
 746                         return $first . $second;
 747                 } else {
 748                         return '';
 749                 }
 750         }
 751
 752         /**
 753          * This is called if a write operation is possible from the generated HTML
 754          */
 755         function preventClickjacking( $enable = true ) {
 756                 $this->preventClickjacking = $enable;
 757         }
 758
 759         /**
 760          * Get the "prevent clickjacking" flag
 761          */
 762         function getPreventClickjacking() {
 763                 return $this->preventClickjacking;
 764         }
 765 }
 766
 767 /**
 768  * Backwards-compatibility aliases
 769  */
 770 class PageHistory extends HistoryPage {}
 771 class PageHistoryPager extends HistoryPager {}