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