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