includes/actions/HistoryAction.php

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