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