includes/actions/HistoryAction.php

   1 <?php
   2 /**
   3  * Page history
   4  *
   5  * Split off from Article.php and Skin.php, 2003-12-22
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License as published by
   9  * the Free Software Foundation; either version 2 of the License, or
  10  * (at your option) any later version.
  11  *
  12  * This program is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  15  * GNU General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU General Public License along
  18  * with this program; if not, write to the Free Software Foundation, Inc.,
  19  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  20  * http://www.gnu.org/copyleft/gpl.html
  21  *
  22  * @file
  23  * @ingroup Actions
  24  */
  25
  26 /**
  27  * This class handles printing the history page for an article. In order to
  28  * be efficient, it uses timestamps rather than offsets for paging, to avoid
  29  * costly LIMIT,offset queries.
  30  *
  31  * Construct it by passing in an Article, and call $h->history() to print the
  32  * history.
  33  *
  34  * @ingroup Actions
  35  */
  36 class HistoryAction extends FormlessAction {
  37         const DIR_PREV = 0;
  38         const DIR_NEXT = 1;
  39
  40         /** @var array Array of message keys and strings */
  41         public $message;
  42
  43         public function getName() {
  44                 return 'history';
  45         }
  46
  47         public function requiresWrite() {
  48                 return false;
  49         }
  50
  51         public function requiresUnblock() {
  52                 return false;
  53         }
  54
  55         protected function getPageTitle() {
  56                 return $this->msg( 'history-title', $this->getTitle()->getPrefixedText() )->text();
  57         }
  58
  59         protected function getDescription() {
  60                 // Creation of a subtitle link pointing to [[Special:Log]]
  61                 return Linker::linkKnown(
  62                         SpecialPage::getTitleFor( 'Log' ),
  63                         $this->msg( 'viewpagelogs' )->escaped(),
  64                         [],
  65                         [ 'page' => $this->getTitle()->getPrefixedText() ]
  66                 );
  67         }
  68
  69         /**
  70          * @return WikiPage|Article|ImagePage|CategoryPage|Page The Article object we are working on.
  71          */
  72         public function getArticle() {
  73                 return $this->page;
  74         }
  75
  76         /**
  77          * As we use the same small set of messages in various methods and that
  78          * they are called often, we call them once and save them in $this->message
  79          */
  80         private function preCacheMessages() {
  81                 // Precache various messages
  82                 if ( !isset( $this->message ) ) {
  83                         $msgs = [ 'cur', 'last', 'pipe-separator' ];
  84                         foreach ( $msgs as $msg ) {
  85                                 $this->message[$msg] = $this->msg( $msg )->escaped();
  86                         }
  87                 }
  88         }
  89
  90         /**
  91          * Print the history page for an article.
  92          */
  93         function onView() {
  94                 $out = $this->getOutput();
  95                 $request = $this->getRequest();
  96
  97                 /**
  98                  * Allow client caching.
  99                  */
 100                 if ( $out->checkLastModified( $this->page->getTouched() ) ) {
 101                         return; // Client cache fresh and headers sent, nothing more to do.
 102                 }
 103
 104                 $this->preCacheMessages();
 105                 $config = $this->context->getConfig();
 106
 107                 # Fill in the file cache if not set already
 108                 if ( HTMLFileCache::useFileCache( $this->getContext() ) ) {
 109                         $cache = new HTMLFileCache( $this->getTitle(), 'history' );
 110                         if ( !$cache->isCacheGood( /* Assume up to date */ ) ) {
 111                                 ob_start( [ &$cache, 'saveToFileCache' ] );
 112                         }
 113                 }
 114
 115                 // Setup page variables.
 116                 $out->setFeedAppendQuery( 'action=history' );
 117                 $out->addModules( 'mediawiki.action.history' );
 118                 $out->addModuleStyles( [
 119                         'mediawiki.action.history.styles',
 120                         'mediawiki.special.changeslist',
 121                 ] );
 122                 if ( $config->get( 'UseMediaWikiUIEverywhere' ) ) {
 123                         $out = $this->getOutput();
 124                         $out->addModuleStyles( [
 125                                 'mediawiki.ui.input',
 126                                 'mediawiki.ui.checkbox',
 127                         ] );
 128                 }
 129
 130                 // Handle atom/RSS feeds.
 131                 $feedType = $request->getVal( 'feed' );
 132                 if ( $feedType ) {
 133                         $this->feed( $feedType );
 134
 135                         return;
 136                 }
 137
 138                 $this->addHelpLink( '//meta.wikimedia.org/wiki/Special:MyLanguage/Help:Page_history', true );
 139
 140                 // Fail nicely if article doesn't exist.
 141                 if ( !$this->page->exists() ) {
 142                         global $wgSend404Code;
 143                         if ( $wgSend404Code ) {
 144                                 $out->setStatusCode( 404 );
 145                         }
 146                         $out->addWikiMsg( 'nohistory' );
 147                         # show deletion/move log if there is an entry
 148                         LogEventsList::showLogExtract(
 149                                 $out,
 150                                 [ 'delete', 'move' ],
 151                                 $this->getTitle(),
 152                                 '',
 153                                 [ 'lim' => 10,
 154                                         'conds' => [ "log_action != 'revision'" ],
 155                                         'showIfEmpty' => false,
 156                                         'msgKey' => [ 'moveddeleted-notice' ]
 157                                 ]
 158                         );
 159
 160                         return;
 161                 }
 162
 163                 /**
 164                  * Add date selector to quickly get to a certain time
 165                  */
 166                 $year = $request->getInt( 'year' );
 167                 $month = $request->getInt( 'month' );
 168                 $tagFilter = $request->getVal( 'tagfilter' );
 169                 $tagSelector = ChangeTags::buildTagFilterSelector( $tagFilter );
 170
 171                 /**
 172                  * Option to show only revisions that have been (partially) hidden via RevisionDelete
 173                  */
 174                 if ( $request->getBool( 'deleted' ) ) {
 175                         $conds = [ 'rev_deleted != 0' ];
 176                 } else {
 177                         $conds = [];
 178                 }
 179                 if ( $this->getUser()->isAllowed( 'deletedhistory' ) ) {
 180                         $checkDeleted = Xml::checkLabel( $this->msg( 'history-show-deleted' )->text(),
 181                                 'deleted', 'mw-show-deleted-only', $request->getBool( 'deleted' ) ) . "\n";
 182                 } else {
 183                         $checkDeleted = '';
 184                 }
 185
 186                 // Add the general form
 187                 $action = htmlspecialchars( wfScript() );
 188                 $out->addHTML(
 189                         "<form action=\"$action\" method=\"get\" id=\"mw-history-searchform\">" .
 190                         Xml::fieldset(
 191                                 $this->msg( 'history-fieldset-title' )->text(),
 192                                 false,
 193                                 [ 'id' => 'mw-history-search' ]
 194                         ) .
 195                         Html::hidden( 'title', $this->getTitle()->getPrefixedDBkey() ) . "\n" .
 196                         Html::hidden( 'action', 'history' ) . "\n" .
 197                         Xml::dateMenu(
 198                                 ( $year == null ? MWTimestamp::getLocalInstance()->format( 'Y' ) : $year ),
 199                                 $month
 200                         ) . '&#160;' .
 201                         ( $tagSelector ? ( implode( '&#160;', $tagSelector ) . '&#160;' ) : '' ) .
 202                         $checkDeleted .
 203                         Html::submitButton(
 204                                 $this->msg( 'historyaction-submit' )->text(),
 205                                 [],
 206                                 [ 'mw-ui-progressive' ]
 207                         ) . "\n" .
 208                         '</fieldset></form>'
 209                 );
 210
 211                 Hooks::run( 'PageHistoryBeforeList', [ &$this->page, $this->getContext() ] );
 212
 213                 // Create and output the list.
 214                 $pager = new HistoryPager( $this, $year, $month, $tagFilter, $conds );
 215                 $out->addHTML(
 216                         $pager->getNavigationBar() .
 217                         $pager->getBody() .
 218                         $pager->getNavigationBar()
 219                 );
 220                 $out->preventClickjacking( $pager->getPreventClickjacking() );
 221         }
 222
 223         /**
 224          * Fetch an array of revisions, specified by a given limit, offset and
 225          * direction. This is now only used by the feeds. It was previously
 226          * used by the main UI but that's now handled by the pager.
 227          *
 228          * @param int $limit The limit number of revisions to get
 229          * @param int $offset
 230          * @param int $direction Either self::DIR_PREV or self::DIR_NEXT
 231          * @return ResultWrapper
 232          */
 233         function fetchRevisions( $limit, $offset, $direction ) {
 234                 // Fail if article doesn't exist.
 235                 if ( !$this->getTitle()->exists() ) {
 236                         return new FakeResultWrapper( [] );
 237                 }
 238
 239                 $dbr = wfGetDB( DB_REPLICA );
 240
 241                 if ( $direction === self::DIR_PREV ) {
 242                         list( $dirs, $oper ) = [ "ASC", ">=" ];
 243                 } else { /* $direction === self::DIR_NEXT */
 244                         list( $dirs, $oper ) = [ "DESC", "<=" ];
 245                 }
 246
 247                 if ( $offset ) {
 248                         $offsets = [ "rev_timestamp $oper " . $dbr->addQuotes( $dbr->timestamp( $offset ) ) ];
 249                 } else {
 250                         $offsets = [];
 251                 }
 252
 253                 $page_id = $this->page->getId();
 254
 255                 return $dbr->select( 'revision',
 256                         Revision::selectFields(),
 257                         array_merge( [ 'rev_page' => $page_id ], $offsets ),
 258                         __METHOD__,
 259                         [ 'ORDER BY' => "rev_timestamp $dirs",
 260                                 'USE INDEX' => 'page_timestamp', 'LIMIT' => $limit ]
 261                 );
 262         }
 263
 264         /**
 265          * Output a subscription feed listing recent edits to this page.
 266          *
 267          * @param string $type Feed type
 268          */
 269         function feed( $type ) {
 270                 if ( !FeedUtils::checkFeedOutput( $type ) ) {
 271                         return;
 272                 }
 273                 $request = $this->getRequest();
 274
 275                 $feedClasses = $this->context->getConfig()->get( 'FeedClasses' );
 276                 /** @var RSSFeed|AtomFeed $feed */
 277                 $feed = new $feedClasses[$type](
 278                         $this->getTitle()->getPrefixedText() . ' - ' .
 279                         $this->msg( 'history-feed-title' )->inContentLanguage()->text(),
 280                         $this->msg( 'history-feed-description' )->inContentLanguage()->text(),
 281                         $this->getTitle()->getFullURL( 'action=history' )
 282                 );
 283
 284                 // Get a limit on number of feed entries. Provide a sane default
 285                 // of 10 if none is defined (but limit to $wgFeedLimit max)
 286                 $limit = $request->getInt( 'limit', 10 );
 287                 $limit = min(
 288                         max( $limit, 1 ),
 289                         $this->context->getConfig()->get( 'FeedLimit' )
 290                 );
 291
 292                 $items = $this->fetchRevisions( $limit, 0, self::DIR_NEXT );
 293
 294                 // Generate feed elements enclosed between header and footer.
 295                 $feed->outHeader();
 296                 if ( $items->numRows() ) {
 297                         foreach ( $items as $row ) {
 298                                 $feed->outItem( $this->feedItem( $row ) );
 299                         }
 300                 } else {
 301                         $feed->outItem( $this->feedEmpty() );
 302                 }
 303                 $feed->outFooter();
 304         }
 305
 306         function feedEmpty() {
 307                 return new FeedItem(
 308                         $this->msg( 'nohistory' )->inContentLanguage()->text(),
 309                         $this->msg( 'history-feed-empty' )->inContentLanguage()->parseAsBlock(),
 310                         $this->getTitle()->getFullURL(),
 311                         wfTimestamp( TS_MW ),
 312                         '',
 313                         $this->getTitle()->getTalkPage()->getFullURL()
 314                 );
 315         }
 316
 317         /**
 318          * Generate a FeedItem object from a given revision table row
 319          * Borrows Recent Changes' feed generation functions for formatting;
 320          * includes a diff to the previous revision (if any).
 321          *
 322          * @param stdClass|array $row Database row
 323          * @return FeedItem
 324          */
 325         function feedItem( $row ) {
 326                 $rev = new Revision( $row );
 327                 $rev->setTitle( $this->getTitle() );
 328                 $text = FeedUtils::formatDiffRow(
 329                         $this->getTitle(),
 330                         $this->getTitle()->getPreviousRevisionID( $rev->getId() ),
 331                         $rev->getId(),
 332                         $rev->getTimestamp(),
 333                         $rev->getComment()
 334                 );
 335                 if ( $rev->getComment() == '' ) {
 336                         global $wgContLang;
 337                         $title = $this->msg( 'history-feed-item-nocomment',
 338                                 $rev->getUserText(),
 339                                 $wgContLang->timeanddate( $rev->getTimestamp() ),
 340                                 $wgContLang->date( $rev->getTimestamp() ),
 341                                 $wgContLang->time( $rev->getTimestamp() ) )->inContentLanguage()->text();
 342                 } else {
 343                         $title = $rev->getUserText() .
 344                                 $this->msg( 'colon-separator' )->inContentLanguage()->text() .
 345                                 FeedItem::stripComment( $rev->getComment() );
 346                 }
 347
 348                 return new FeedItem(
 349                         $title,
 350                         $text,
 351                         $this->getTitle()->getFullURL( 'diff=' . $rev->getId() . '&oldid=prev' ),
 352                         $rev->getTimestamp(),
 353                         $rev->getUserText(),
 354                         $this->getTitle()->getTalkPage()->getFullURL()
 355                 );
 356         }
 357 }
 358
 359 /**
 360  * @ingroup Pager
 361  * @ingroup Actions
 362  */
 363 class HistoryPager extends ReverseChronologicalPager {
 364         /**
 365          * @var bool|stdClass
 366          */
 367         public $lastRow = false;
 368
 369         public $counter, $historyPage, $buttons, $conds;
 370
 371         protected $oldIdChecked;
 372
 373         protected $preventClickjacking = false;
 374         /**
 375          * @var array
 376          */
 377         protected $parentLens;
 378
 379         /** @var bool Whether to show the tag editing UI */
 380         protected $showTagEditUI;
 381
 382         /**
 383          * @param HistoryAction $historyPage
 384          * @param string $year
 385          * @param string $month
 386          * @param string $tagFilter
 387          * @param array $conds
 388          */
 389         function __construct( $historyPage, $year = '', $month = '', $tagFilter = '', $conds = [] ) {
 390                 parent::__construct( $historyPage->getContext() );
 391                 $this->historyPage = $historyPage;
 392                 $this->tagFilter = $tagFilter;
 393                 $this->getDateCond( $year, $month );
 394                 $this->conds = $conds;
 395                 $this->showTagEditUI = ChangeTags::showTagEditingUI( $this->getUser() );
 396         }
 397
 398         // For hook compatibility...
 399         function getArticle() {
 400                 return $this->historyPage->getArticle();
 401         }
 402
 403         function getSqlComment() {
 404                 if ( $this->conds ) {
 405                         return 'history page filtered'; // potentially slow, see CR r58153
 406                 } else {
 407                         return 'history page unfiltered';
 408                 }
 409         }
 410
 411         function getQueryInfo() {
 412                 $queryInfo = [
 413                         'tables' => [ 'revision', 'user' ],
 414                         'fields' => array_merge( Revision::selectFields(), Revision::selectUserFields() ),
 415                         'conds' => array_merge(
 416                                 [ 'rev_page' => $this->getWikiPage()->getId() ],
 417                                 $this->conds ),
 418                         'options' => [ 'USE INDEX' => [ 'revision' => 'page_timestamp' ] ],
 419                         'join_conds' => [ 'user' => Revision::userJoinCond() ],
 420                 ];
 421                 ChangeTags::modifyDisplayQuery(
 422                         $queryInfo['tables'],
 423                         $queryInfo['fields'],
 424                         $queryInfo['conds'],
 425                         $queryInfo['join_conds'],
 426                         $queryInfo['options'],
 427                         $this->tagFilter
 428                 );
 429                 Hooks::run( 'PageHistoryPager::getQueryInfo', [ &$this, &$queryInfo ] );
 430
 431                 return $queryInfo;
 432         }
 433
 434         function getIndexField() {
 435                 return 'rev_timestamp';
 436         }
 437
 438         /**
 439          * @param stdClass $row
 440          * @return string
 441          */
 442         function formatRow( $row ) {
 443                 if ( $this->lastRow ) {
 444                         $latest = ( $this->counter == 1 && $this->mIsFirst );
 445                         $firstInList = $this->counter == 1;
 446                         $this->counter++;
 447
 448                         $notifTimestamp = $this->getConfig()->get( 'ShowUpdatedMarker' )
 449                                 ? $this->getTitle()->getNotificationTimestamp( $this->getUser() )
 450                                 : false;
 451
 452                         $s = $this->historyLine(
 453                                 $this->lastRow, $row, $notifTimestamp, $latest, $firstInList );
 454                 } else {
 455                         $s = '';
 456                 }
 457                 $this->lastRow = $row;
 458
 459                 return $s;
 460         }
 461
 462         function doBatchLookups() {
 463                 if ( !Hooks::run( 'PageHistoryPager::doBatchLookups', [ $this, $this->mResult ] ) ) {
 464                         return;
 465                 }
 466
 467                 # Do a link batch query
 468                 $this->mResult->seek( 0 );
 469                 $batch = new LinkBatch();
 470                 $revIds = [];
 471                 foreach ( $this->mResult as $row ) {
 472                         if ( $row->rev_parent_id ) {
 473                                 $revIds[] = $row->rev_parent_id;
 474                         }
 475                         if ( !is_null( $row->user_name ) ) {
 476                                 $batch->add( NS_USER, $row->user_name );
 477                                 $batch->add( NS_USER_TALK, $row->user_name );
 478                         } else { # for anons or usernames of imported revisions
 479                                 $batch->add( NS_USER, $row->rev_user_text );
 480                                 $batch->add( NS_USER_TALK, $row->rev_user_text );
 481                         }
 482                 }
 483                 $this->parentLens = Revision::getParentLengths( $this->mDb, $revIds );
 484                 $batch->execute();
 485                 $this->mResult->seek( 0 );
 486         }
 487
 488         /**
 489          * Creates begin of history list with a submit button
 490          *
 491          * @return string HTML output
 492          */
 493         function getStartBody() {
 494                 $this->lastRow = false;
 495                 $this->counter = 1;
 496                 $this->oldIdChecked = 0;
 497
 498                 $this->getOutput()->wrapWikiMsg( "<div class='mw-history-legend'>\n$1\n</div>", 'histlegend' );
 499                 $s = Html::openElement( 'form', [ 'action' => wfScript(),
 500                         'id' => 'mw-history-compare' ] ) . "\n";
 501                 $s .= Html::hidden( 'title', $this->getTitle()->getPrefixedDBkey() ) . "\n";
 502                 $s .= Html::hidden( 'action', 'historysubmit' ) . "\n";
 503                 $s .= Html::hidden( 'type', 'revision' ) . "\n";
 504
 505                 // Button container stored in $this->buttons for re-use in getEndBody()
 506                 $this->buttons = '<div>';
 507                 $className = 'historysubmit mw-history-compareselectedversions-button';
 508                 $attrs = [ 'class' => $className ]
 509                         + Linker::tooltipAndAccesskeyAttribs( 'compareselectedversions' );
 510                 $this->buttons .= $this->submitButton( $this->msg( 'compareselectedversions' )->text(),
 511                         $attrs
 512                 ) . "\n";
 513
 514                 $user = $this->getUser();
 515                 $actionButtons = '';
 516                 if ( $user->isAllowed( 'deleterevision' ) ) {
 517                         $actionButtons .= $this->getRevisionButton( 'revisiondelete', 'showhideselectedversions' );
 518                 }
 519                 if ( $this->showTagEditUI ) {
 520                         $actionButtons .= $this->getRevisionButton( 'editchangetags', 'history-edit-tags' );
 521                 }
 522                 if ( $actionButtons ) {
 523                         $this->buttons .= Xml::tags( 'div', [ 'class' =>
 524                                 'mw-history-revisionactions' ], $actionButtons );
 525                 }
 526
 527                 if ( $user->isAllowed( 'deleterevision' ) || $this->showTagEditUI ) {
 528                         $this->buttons .= ( new ListToggle( $this->getOutput() ) )->getHTML();
 529                 }
 530
 531                 $this->buttons .= '</div>';
 532
 533                 $s .= $this->buttons;
 534                 $s .= '<ul id="pagehistory">' . "\n";
 535
 536                 return $s;
 537         }
 538
 539         private function getRevisionButton( $name, $msg ) {
 540                 $this->preventClickjacking();
 541                 # Note bug #20966, <button> is non-standard in IE<8
 542                 $element = Html::element(
 543                         'button',
 544                         [
 545                                 'type' => 'submit',
 546                                 'name' => $name,
 547                                 'value' => '1',
 548                                 'class' => "historysubmit mw-history-$name-button",
 549                         ],
 550                         $this->msg( $msg )->text()
 551                 ) . "\n";
 552                 return $element;
 553         }
 554
 555         function getEndBody() {
 556                 if ( $this->lastRow ) {
 557                         $latest = $this->counter == 1 && $this->mIsFirst;
 558                         $firstInList = $this->counter == 1;
 559                         if ( $this->mIsBackwards ) {
 560                                 # Next row is unknown, but for UI reasons, probably exists if an offset has been specified
 561                                 if ( $this->mOffset == '' ) {
 562                                         $next = null;
 563                                 } else {
 564                                         $next = 'unknown';
 565                                 }
 566                         } else {
 567                                 # The next row is the past-the-end row
 568                                 $next = $this->mPastTheEndRow;
 569                         }
 570                         $this->counter++;
 571
 572                         $notifTimestamp = $this->getConfig()->get( 'ShowUpdatedMarker' )
 573                                 ? $this->getTitle()->getNotificationTimestamp( $this->getUser() )
 574                                 : false;
 575
 576                         $s = $this->historyLine(
 577                                 $this->lastRow, $next, $notifTimestamp, $latest, $firstInList );
 578                 } else {
 579                         $s = '';
 580                 }
 581                 $s .= "</ul>\n";
 582                 # Add second buttons only if there is more than one rev
 583                 if ( $this->getNumRows() > 2 ) {
 584                         $s .= $this->buttons;
 585                 }
 586                 $s .= '</form>';
 587
 588                 return $s;
 589         }
 590
 591         /**
 592          * Creates a submit button
 593          *
 594          * @param string $message Text of the submit button, will be escaped
 595          * @param array $attributes Attributes
 596          * @return string HTML output for the submit button
 597          */
 598         function submitButton( $message, $attributes = [] ) {
 599                 # Disable submit button if history has 1 revision only
 600                 if ( $this->getNumRows() > 1 ) {
 601                         return Html::submitButton( $message, $attributes );
 602                 } else {
 603                         return '';
 604                 }
 605         }
 606
 607         /**
 608          * Returns a row from the history printout.
 609          *
 610          * @todo document some more, and maybe clean up the code (some params redundant?)
 611          *
 612          * @param stdClass $row The database row corresponding to the previous line.
 613          * @param mixed $next The database row corresponding to the next line
 614          *   (chronologically previous)
 615          * @param bool|string $notificationtimestamp
 616          * @param bool $latest Whether this row corresponds to the page's latest revision.
 617          * @param bool $firstInList Whether this row corresponds to the first
 618          *   displayed on this history page.
 619          * @return string HTML output for the row
 620          */
 621         function historyLine( $row, $next, $notificationtimestamp = false,
 622                 $latest = false, $firstInList = false ) {
 623                 $rev = new Revision( $row );
 624                 $rev->setTitle( $this->getTitle() );
 625
 626                 if ( is_object( $next ) ) {
 627                         $prevRev = new Revision( $next );
 628                         $prevRev->setTitle( $this->getTitle() );
 629                 } else {
 630                         $prevRev = null;
 631                 }
 632
 633                 $curlink = $this->curLink( $rev, $latest );
 634                 $lastlink = $this->lastLink( $rev, $next );
 635                 $curLastlinks = $curlink . $this->historyPage->message['pipe-separator'] . $lastlink;
 636                 $histLinks = Html::rawElement(
 637                         'span',
 638                         [ 'class' => 'mw-history-histlinks' ],
 639                         $this->msg( 'parentheses' )->rawParams( $curLastlinks )->escaped()
 640                 );
 641
 642                 $diffButtons = $this->diffButtons( $rev, $firstInList );
 643                 $s = $histLinks . $diffButtons;
 644
 645                 $link = $this->revLink( $rev );
 646                 $classes = [];
 647
 648                 $del = '';
 649                 $user = $this->getUser();
 650                 $canRevDelete = $user->isAllowed( 'deleterevision' );
 651                 // Show checkboxes for each revision, to allow for revision deletion and
 652                 // change tags
 653                 if ( $canRevDelete || $this->showTagEditUI ) {
 654                         $this->preventClickjacking();
 655                         // If revision was hidden from sysops and we don't need the checkbox
 656                         // for anything else, disable it
 657                         if ( !$this->showTagEditUI && !$rev->userCan( Revision::DELETED_RESTRICTED, $user ) ) {
 658                                 $del = Xml::check( 'deleterevisions', false, [ 'disabled' => 'disabled' ] );
 659                         // Otherwise, enable the checkbox...
 660                         } else {
 661                                 $del = Xml::check( 'showhiderevisions', false,
 662                                         [ 'name' => 'ids[' . $rev->getId() . ']' ] );
 663                         }
 664                 // User can only view deleted revisions...
 665                 } elseif ( $rev->getVisibility() && $user->isAllowed( 'deletedhistory' ) ) {
 666                         // If revision was hidden from sysops, disable the link
 667                         if ( !$rev->userCan( Revision::DELETED_RESTRICTED, $user ) ) {
 668                                 $del = Linker::revDeleteLinkDisabled( false );
 669                         // Otherwise, show the link...
 670                         } else {
 671                                 $query = [ 'type' => 'revision',
 672                                         'target' => $this->getTitle()->getPrefixedDBkey(), 'ids' => $rev->getId() ];
 673                                 $del .= Linker::revDeleteLink( $query,
 674                                         $rev->isDeleted( Revision::DELETED_RESTRICTED ), false );
 675                         }
 676                 }
 677                 if ( $del ) {
 678                         $s .= " $del ";
 679                 }
 680
 681                 $lang = $this->getLanguage();
 682                 $dirmark = $lang->getDirMark();
 683
 684                 $s .= " $link";
 685                 $s .= $dirmark;
 686                 $s .= " <span class='history-user'>" .
 687                         Linker::revUserTools( $rev, true ) . "</span>";
 688                 $s .= $dirmark;
 689
 690                 if ( $rev->isMinor() ) {
 691                         $s .= ' ' . ChangesList::flag( 'minor', $this->getContext() );
 692                 }
 693
 694                 # Sometimes rev_len isn't populated
 695                 if ( $rev->getSize() !== null ) {
 696                         # Size is always public data
 697                         $prevSize = isset( $this->parentLens[$row->rev_parent_id] )
 698                                 ? $this->parentLens[$row->rev_parent_id]
 699                                 : 0;
 700                         $sDiff = ChangesList::showCharacterDifference( $prevSize, $rev->getSize() );
 701                         $fSize = Linker::formatRevisionSize( $rev->getSize() );
 702                         $s .= ' <span class="mw-changeslist-separator">. .</span> ' . "$fSize $sDiff";
 703                 }
 704
 705                 # Text following the character difference is added just before running hooks
 706                 $s2 = Linker::revComment( $rev, false, true );
 707
 708                 if ( $notificationtimestamp && ( $row->rev_timestamp >= $notificationtimestamp ) ) {
 709                         $s2 .= ' <span class="updatedmarker">' . $this->msg( 'updatedmarker' )->escaped() . '</span>';
 710                         $classes[] = 'mw-history-line-updated';
 711                 }
 712
 713                 $tools = [];
 714
 715                 # Rollback and undo links
 716                 if ( $prevRev && $this->getTitle()->quickUserCan( 'edit', $user ) ) {
 717                         if ( $latest && $this->getTitle()->quickUserCan( 'rollback', $user ) ) {
 718                                 // Get a rollback link without the brackets
 719                                 $rollbackLink = Linker::generateRollback(
 720                                         $rev,
 721                                         $this->getContext(),
 722                                         [ 'verify', 'noBrackets' ]
 723                                 );
 724                                 if ( $rollbackLink ) {
 725                                         $this->preventClickjacking();
 726                                         $tools[] = $rollbackLink;
 727                                 }
 728                         }
 729
 730                         if ( !$rev->isDeleted( Revision::DELETED_TEXT )
 731                                 && !$prevRev->isDeleted( Revision::DELETED_TEXT )
 732                         ) {
 733                                 # Create undo tooltip for the first (=latest) line only
 734                                 $undoTooltip = $latest
 735                                         ? [ 'title' => $this->msg( 'tooltip-undo' )->text() ]
 736                                         : [];
 737                                 $undolink = Linker::linkKnown(
 738                                         $this->getTitle(),
 739                                         $this->msg( 'editundo' )->escaped(),
 740                                         $undoTooltip,
 741                                         [
 742                                                 'action' => 'edit',
 743                                                 'undoafter' => $prevRev->getId(),
 744                                                 'undo' => $rev->getId()
 745                                         ]
 746                                 );
 747                                 $tools[] = "<span class=\"mw-history-undo\">{$undolink}</span>";
 748                         }
 749                 }
 750                 // Allow extension to add their own links here
 751                 Hooks::run( 'HistoryRevisionTools', [ $rev, &$tools, $prevRev, $user ] );
 752
 753                 if ( $tools ) {
 754                         $s2 .= ' ' . $this->msg( 'parentheses' )->rawParams( $lang->pipeList( $tools ) )->escaped();
 755                 }
 756
 757                 # Tags
 758                 list( $tagSummary, $newClasses ) = ChangeTags::formatSummaryRow(
 759                         $row->ts_tags,
 760                         'history',
 761                         $this->getContext()
 762                 );
 763                 $classes = array_merge( $classes, $newClasses );
 764                 if ( $tagSummary !== '' ) {
 765                         $s2 .= " $tagSummary";
 766                 }
 767
 768                 # Include separator between character difference and following text
 769                 if ( $s2 !== '' ) {
 770                         $s .= ' <span class="mw-changeslist-separator">. .</span> ' . $s2;
 771                 }
 772
 773                 Hooks::run( 'PageHistoryLineEnding', [ $this, &$row, &$s, &$classes ] );
 774
 775                 $attribs = [];
 776                 if ( $classes ) {
 777                         $attribs['class'] = implode( ' ', $classes );
 778                 }
 779
 780                 return Xml::tags( 'li', $attribs, $s ) . "\n";
 781         }
 782
 783         /**
 784          * Create a link to view this revision of the page
 785          *
 786          * @param Revision $rev
 787          * @return string
 788          */
 789         function revLink( $rev ) {
 790                 $date = $this->getLanguage()->userTimeAndDate( $rev->getTimestamp(), $this->getUser() );
 791                 $date = htmlspecialchars( $date );
 792                 if ( $rev->userCan( Revision::DELETED_TEXT, $this->getUser() ) ) {
 793                         $link = Linker::linkKnown(
 794                                 $this->getTitle(),
 795                                 $date,
 796                                 [ 'class' => 'mw-changeslist-date' ],
 797                                 [ 'oldid' => $rev->getId() ]
 798                         );
 799                 } else {
 800                         $link = $date;
 801                 }
 802                 if ( $rev->isDeleted( Revision::DELETED_TEXT ) ) {
 803                         $link = "<span class=\"history-deleted\">$link</span>";
 804                 }
 805
 806                 return $link;
 807         }
 808
 809         /**
 810          * Create a diff-to-current link for this revision for this page
 811          *
 812          * @param Revision $rev
 813          * @param bool $latest This is the latest revision of the page?
 814          * @return string
 815          */
 816         function curLink( $rev, $latest ) {
 817                 $cur = $this->historyPage->message['cur'];
 818                 if ( $latest || !$rev->userCan( Revision::DELETED_TEXT, $this->getUser() ) ) {
 819                         return $cur;
 820                 } else {
 821                         return Linker::linkKnown(
 822                                 $this->getTitle(),
 823                                 $cur,
 824                                 [],
 825                                 [
 826                                         'diff' => $this->getWikiPage()->getLatest(),
 827                                         'oldid' => $rev->getId()
 828                                 ]
 829                         );
 830                 }
 831         }
 832
 833         /**
 834          * Create a diff-to-previous link for this revision for this page.
 835          *
 836          * @param Revision $prevRev The revision being displayed
 837          * @param stdClass|string|null $next The next revision in list (that is
 838          *        the previous one in chronological order).
 839          *        May either be a row, "unknown" or null.
 840          * @return string
 841          */
 842         function lastLink( $prevRev, $next ) {
 843                 $last = $this->historyPage->message['last'];
 844
 845                 if ( $next === null ) {
 846                         # Probably no next row
 847                         return $last;
 848                 }
 849
 850                 if ( $next === 'unknown' ) {
 851                         # Next row probably exists but is unknown, use an oldid=prev link
 852                         return Linker::linkKnown(
 853                                 $this->getTitle(),
 854                                 $last,
 855                                 [],
 856                                 [
 857                                         'diff' => $prevRev->getId(),
 858                                         'oldid' => 'prev'
 859                                 ]
 860                         );
 861                 }
 862
 863                 $nextRev = new Revision( $next );
 864
 865                 if ( !$prevRev->userCan( Revision::DELETED_TEXT, $this->getUser() )
 866                         || !$nextRev->userCan( Revision::DELETED_TEXT, $this->getUser() )
 867                 ) {
 868                         return $last;
 869                 }
 870
 871                 return Linker::linkKnown(
 872                         $this->getTitle(),
 873                         $last,
 874                         [],
 875                         [
 876                                 'diff' => $prevRev->getId(),
 877                                 'oldid' => $next->rev_id
 878                         ]
 879                 );
 880         }
 881
 882         /**
 883          * Create radio buttons for page history
 884          *
 885          * @param Revision $rev
 886          * @param bool $firstInList Is this version the first one?
 887          *
 888          * @return string HTML output for the radio buttons
 889          */
 890         function diffButtons( $rev, $firstInList ) {
 891                 if ( $this->getNumRows() > 1 ) {
 892                         $id = $rev->getId();
 893                         $radio = [ 'type' => 'radio', 'value' => $id ];
 894                         /** @todo Move title texts to javascript */
 895                         if ( $firstInList ) {
 896                                 $first = Xml::element( 'input',
 897                                         array_merge( $radio, [
 898                                                 'style' => 'visibility:hidden',
 899                                                 'name' => 'oldid',
 900                                                 'id' => 'mw-oldid-null' ] )
 901                                 );
 902                                 $checkmark = [ 'checked' => 'checked' ];
 903                         } else {
 904                                 # Check visibility of old revisions
 905                                 if ( !$rev->userCan( Revision::DELETED_TEXT, $this->getUser() ) ) {
 906                                         $radio['disabled'] = 'disabled';
 907                                         $checkmark = []; // We will check the next possible one
 908                                 } elseif ( !$this->oldIdChecked ) {
 909                                         $checkmark = [ 'checked' => 'checked' ];
 910                                         $this->oldIdChecked = $id;
 911                                 } else {
 912                                         $checkmark = [];
 913                                 }
 914                                 $first = Xml::element( 'input',
 915                                         array_merge( $radio, $checkmark, [
 916                                                 'name' => 'oldid',
 917                                                 'id' => "mw-oldid-$id" ] ) );
 918                                 $checkmark = [];
 919                         }
 920                         $second = Xml::element( 'input',
 921                                 array_merge( $radio, $checkmark, [
 922                                         'name' => 'diff',
 923                                         'id' => "mw-diff-$id" ] ) );
 924
 925                         return $first . $second;
 926                 } else {
 927                         return '';
 928                 }
 929         }
 930
 931         /**
 932          * This is called if a write operation is possible from the generated HTML
 933          * @param bool $enable
 934          */
 935         function preventClickjacking( $enable = true ) {
 936                 $this->preventClickjacking = $enable;
 937         }
 938
 939         /**
 940          * Get the "prevent clickjacking" flag
 941          * @return bool
 942          */
 943         function getPreventClickjacking() {
 944                 return $this->preventClickjacking;
 945         }
 946
 947 }