includes/actions/HistoryAction.php

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