includes/diff/DifferenceInterface.php

   1 <?php
   2 /**
   3  * @defgroup DifferenceEngine DifferenceEngine
   4  */
   5
   6 /**
   7  * Constant to indicate diff cache compatibility.
   8  * Bump this when changing the diff formatting in a way that
   9  * fixes important bugs or such to force cached diff views to
  10  * clear.
  11  */
  12 define( 'MW_DIFF_VERSION', '1.11a' );
  13
  14 /**
  15  * @todo document
  16  * @ingroup DifferenceEngine
  17  */
  18 class DifferenceEngine {
  19         /**#@+
  20          * @private
  21          */
  22         var $mOldid, $mNewid, $mTitle;
  23         var $mOldtitle, $mNewtitle, $mPagetitle;
  24         var $mOldtext, $mNewtext;
  25         var $mOldPage, $mNewPage;
  26         var $mRcidMarkPatrolled;
  27         var $mOldRev, $mNewRev;
  28         var $mRevisionsLoaded = false; // Have the revisions been loaded
  29         var $mTextLoaded = 0; // How many text blobs have been loaded, 0, 1 or 2?
  30         var $mCacheHit = false; // Was the diff fetched from cache?
  31         var $htmldiff;
  32
  33         /**
  34          * Set this to true to add debug info to the HTML output.
  35          * Warning: this may cause RSS readers to spuriously mark articles as "new"
  36          * (bug 20601)
  37          */
  38         var $enableDebugComment = false;
  39
  40         // If true, line X is not displayed when X is 1, for example to increase
  41         // readability and conserve space with many small diffs.
  42         protected $mReducedLineNumbers = false;
  43
  44         protected $unhide = false;
  45         /**#@-*/
  46
  47         /**
  48          * Constructor
  49          * @param $titleObj Title object that the diff is associated with
  50          * @param $old Integer: old ID we want to show and diff with.
  51          * @param $new String: either 'prev' or 'next'.
  52          * @param $rcid Integer: ??? FIXME (default 0)
  53          * @param $refreshCache boolean If set, refreshes the diff cache
  54          * @param $htmldiff boolean If set, output using HTMLDiff instead of raw wikicode diff
  55          * @param $unhide boolean If set, allow viewing deleted revs
  56          */
  57         function __construct( $titleObj = null, $old = 0, $new = 0, $rcid = 0,
  58                 $refreshCache = false, $htmldiff = false, $unhide = false )
  59         {
  60                 if ( $titleObj ) {
  61                         $this->mTitle = $titleObj;
  62                 } else {
  63                         global $wgTitle;
  64                         $this->mTitle = $wgTitle;
  65                 }
  66                 wfDebug("DifferenceEngine old '$old' new '$new' rcid '$rcid'\n");
  67
  68                 if ( 'prev' === $new ) {
  69                         # Show diff between revision $old and the previous one.
  70                         # Get previous one from DB.
  71                         $this->mNewid = intval($old);
  72                         $this->mOldid = $this->mTitle->getPreviousRevisionID( $this->mNewid );
  73                 } elseif ( 'next' === $new ) {
  74                         # Show diff between revision $old and the next one.
  75                         # Get next one from DB.
  76                         $this->mOldid = intval($old);
  77                         $this->mNewid = $this->mTitle->getNextRevisionID( $this->mOldid );
  78                         if ( false === $this->mNewid ) {
  79                                 # if no result, NewId points to the newest old revision. The only newer
  80                                 # revision is cur, which is "0".
  81                                 $this->mNewid = 0;
  82                         }
  83                 } else {
  84                         $this->mOldid = intval($old);
  85                         $this->mNewid = intval($new);
  86                         wfRunHooks( 'NewDifferenceEngine', array(&$titleObj, &$this->mOldid, &$this->mNewid, $old, $new) );
  87                 }
  88                 $this->mRcidMarkPatrolled = intval($rcid);  # force it to be an integer
  89                 $this->mRefreshCache = $refreshCache;
  90                 $this->htmldiff = $htmldiff;
  91                 $this->unhide = $unhide;
  92         }
  93
  94         function setReducedLineNumbers( $value = true ) {
  95                 $this->mReducedLineNumbers = $value;
  96         }
  97
  98         function getTitle() {
  99                 return $this->mTitle;
 100         }
 101
 102         function wasCacheHit() {
 103                 return $this->mCacheHit;
 104         }
 105
 106         function getOldid() {
 107                 return $this->mOldid;
 108         }
 109
 110         function getNewid() {
 111                 return $this->mNewid;
 112         }
 113
 114         function showDiffPage( $diffOnly = false ) {
 115                 global $wgUser, $wgOut, $wgUseExternalEditor, $wgUseRCPatrol, $wgEnableHtmlDiff;
 116                 wfProfileIn( __METHOD__ );
 117
 118
 119                 # If external diffs are enabled both globally and for the user,
 120                 # we'll use the application/x-external-editor interface to call
 121                 # an external diff tool like kompare, kdiff3, etc.
 122                 if($wgUseExternalEditor && $wgUser->getOption('externaldiff')) {
 123                         global $wgInputEncoding,$wgServer,$wgScript,$wgLang;
 124                         $wgOut->disable();
 125                         header ( "Content-type: application/x-external-editor; charset=".$wgInputEncoding );
 126                         $url1=$this->mTitle->getFullURL( array(
 127                                 'action' => 'raw',
 128                                 'oldid' => $this->mOldid
 129                         ) );
 130                         $url2=$this->mTitle->getFullURL( array(
 131                                 'action' => 'raw',
 132                                 'oldid' => $this->mNewid
 133                         ) );
 134                         $special=$wgLang->getNsText(NS_SPECIAL);
 135                         $control=<<<CONTROL
 136                         [Process]
 137                         Type=Diff text
 138                         Engine=MediaWiki
 139                         Script={$wgServer}{$wgScript}
 140                         Special namespace={$special}
 141
 142                         [File]
 143                         Extension=wiki
 144                         URL=$url1
 145
 146                         [File 2]
 147                         Extension=wiki
 148                         URL=$url2
 149 CONTROL;
 150                         echo($control);
 151                         return;
 152                 }
 153
 154                 $wgOut->setArticleFlag( false );
 155                 if ( !$this->loadRevisionData() ) {
 156                         $t = $this->mTitle->getPrefixedText();
 157                         $d = wfMsgExt( 'missingarticle-diff', array( 'escape' ), $this->mOldid, $this->mNewid );
 158                         $wgOut->setPagetitle( wfMsg( 'errorpagetitle' ) );
 159                         $wgOut->addWikiMsg( 'missing-article', "<nowiki>$t</nowiki>", $d );
 160                         wfProfileOut( __METHOD__ );
 161                         return;
 162                 }
 163
 164                 wfRunHooks( 'DiffViewHeader', array( $this, $this->mOldRev, $this->mNewRev ) );
 165
 166                 if ( $this->mNewRev->isCurrent() ) {
 167                         $wgOut->setArticleFlag( true );
 168                 }
 169
 170                 # mOldid is false if the difference engine is called with a "vague" query for
 171                 # a diff between a version V and its previous version V' AND the version V
 172                 # is the first version of that article. In that case, V' does not exist.
 173                 if ( $this->mOldid === false ) {
 174                         $this->showFirstRevision();
 175                         $this->renderNewRevision();  // should we respect $diffOnly here or not?
 176                         wfProfileOut( __METHOD__ );
 177                         return;
 178                 }
 179
 180                 $wgOut->suppressQuickbar();
 181
 182                 $oldTitle = $this->mOldPage->getPrefixedText();
 183                 $newTitle = $this->mNewPage->getPrefixedText();
 184                 if( $oldTitle == $newTitle ) {
 185                         $wgOut->setPageTitle( $newTitle );
 186                 } else {
 187                         $wgOut->setPageTitle( $oldTitle . ', ' . $newTitle );
 188                 }
 189                 $wgOut->setSubtitle( wfMsgExt( 'difference', array( 'parseinline' ) ) );
 190                 $wgOut->setRobotPolicy( 'noindex,nofollow' );
 191
 192                 if ( !$this->mOldPage->userCanRead() || !$this->mNewPage->userCanRead() ) {
 193                         $wgOut->loginToUse();
 194                         $wgOut->output();
 195                         $wgOut->disable();
 196                         wfProfileOut( __METHOD__ );
 197                         return;
 198                 }
 199
 200                 $sk = $wgUser->getSkin();
 201
 202                 // Check if page is editable
 203                 $editable = $this->mNewRev->getTitle()->userCan( 'edit' );
 204                 if ( $editable && $this->mNewRev->isCurrent() && $wgUser->isAllowed( 'rollback' ) ) {
 205                         $rollback = '&nbsp;&nbsp;&nbsp;' . $sk->generateRollback( $this->mNewRev );
 206                 } else {
 207                         $rollback = '';
 208                 }
 209
 210                 // Prepare a change patrol link, if applicable
 211                 if( $wgUseRCPatrol && $this->mTitle->userCan('patrol') ) {
 212                         // If we've been given an explicit change identifier, use it; saves time
 213                         if( $this->mRcidMarkPatrolled ) {
 214                                 $rcid = $this->mRcidMarkPatrolled;
 215                                 $rc = RecentChange::newFromId( $rcid );
 216                                 // Already patrolled?
 217                                 $rcid = is_object($rc) && !$rc->getAttribute('rc_patrolled') ? $rcid : 0;
 218                         } else {
 219                                 // Look for an unpatrolled change corresponding to this diff
 220                                 $db = wfGetDB( DB_SLAVE );
 221                                 $change = RecentChange::newFromConds(
 222                                         array(
 223                                         // Redundant user,timestamp condition so we can use the existing index
 224                                                 'rc_user_text'  => $this->mNewRev->getRawUserText(),
 225                                                 'rc_timestamp'  => $db->timestamp( $this->mNewRev->getTimestamp() ),
 226                                                 'rc_this_oldid' => $this->mNewid,
 227                                                 'rc_last_oldid' => $this->mOldid,
 228                                                 'rc_patrolled'  => 0
 229                                         ),
 230                                         __METHOD__
 231                                 );
 232                                 if( $change instanceof RecentChange ) {
 233                                         $rcid = $change->mAttribs['rc_id'];
 234                                         $this->mRcidMarkPatrolled = $rcid;
 235                                 } else {
 236                                         // None found
 237                                         $rcid = 0;
 238                                 }
 239                         }
 240                         // Build the link
 241                         if( $rcid ) {
 242                                 $patrol = ' <span class="patrollink">[' . $sk->link(
 243                                         $this->mTitle,
 244                                         wfMsgHtml( 'markaspatrolleddiff' ),
 245                                         array(),
 246                                         array(
 247                                                 'action' => 'markpatrolled',
 248                                                 'rcid' => $rcid
 249                                         ),
 250                                         array(
 251                                                 'known',
 252                                                 'noclasses'
 253                                         )
 254                                 ) . ']</span>';
 255                         } else {
 256                                 $patrol = '';
 257                         }
 258                 } else {
 259                         $patrol = '';
 260                 }
 261
 262                 # Carry over 'diffonly' param via navigation links
 263                 if( $diffOnly != $wgUser->getBoolOption('diffonly') ) {
 264                         $query['diffonly'] = $diffOnly;
 265                 }
 266
 267                 $htmldiffarg = $this->htmlDiffArgument();
 268
 269                 if( $htmldiffarg ) {
 270                         $query['htmldiff'] = $htmldiffarg['htmldiff'];
 271                 }
 272
 273                 # Make "previous revision link"
 274                 $query['diff'] = 'prev';
 275                 $query['oldid'] = $this->mOldid;
 276
 277                 $prevlink = $sk->link(
 278                         $this->mTitle,
 279                         wfMsgHtml( 'previousdiff' ),
 280                         array(
 281                                 'id' => 'differences-prevlink'
 282                         ),
 283                         $query,
 284                         array(
 285                                 'known',
 286                                 'noclasses'
 287                         )
 288                 );
 289                 # Make "next revision link"
 290                 $query['diff'] = 'next';
 291                 $query['oldid'] = $this->mNewid;
 292
 293                 if( $this->mNewRev->isCurrent() ) {
 294                         $nextlink = '&nbsp;';
 295                 } else {
 296                         $nextlink = $sk->link(
 297                                 $this->mTitle,
 298                                 wfMsgHtml( 'nextdiff' ),
 299                                 array(
 300                                         'id' => 'differences-nextlink'
 301                                 ),
 302                                 $query,
 303                                 array(
 304                                         'known',
 305                                         'noclasses'
 306                                 )
 307                         );
 308                 }
 309
 310                 $oldminor = '';
 311                 $newminor = '';
 312
 313                 if( $this->mOldRev->isMinor() ) {
 314                         $oldminor = ChangesList::flag( 'minor' );
 315                 }
 316                 if( $this->mNewRev->isMinor() ) {
 317                         $newminor = ChangesList::flag( 'minor' );
 318                 }
 319
 320                 $rdel = ''; $ldel = '';
 321                 if( $wgUser->isAllowed( 'deletedrevision' ) ) {
 322                         // Don't show useless link to people who cannot hide revisions
 323                         if( $this->mOldRev->getVisibility() || $wgUser->isAllowed( 'deleterevision' ) ) {
 324                                 if( !$this->mOldRev->userCan( Revision::DELETED_RESTRICTED ) ) {
 325                                         // If revision was hidden from sysops
 326                                         $ldel = Xml::tags( 'span', array( 'class' => 'mw-revdelundel-link' ),
 327                                                 '(' . wfMsgHtml( 'rev-delundel' ) . ')' );
 328                                 } else {
 329                                         $query = array(
 330                                                 'type' => 'revision',
 331                                                 'target' => $this->mOldRev->mTitle->getPrefixedDbkey(),
 332                                                 'ids' => $this->mOldRev->getId()
 333                                         );
 334                                         $ldel = $sk->revDeleteLink( $query, $this->mOldRev->isDeleted( Revision::DELETED_RESTRICTED ) );
 335                                 }
 336                                 $ldel = "&nbsp;&nbsp;&nbsp;$ldel ";
 337                         }
 338                         // Don't show useless link to people who cannot hide revisions
 339                         if( $this->mNewRev->getVisibility() || $wgUser->isAllowed( 'deleterevision' ) ) {
 340                                 if( !$this->mNewRev->userCan( Revision::DELETED_RESTRICTED ) ) {
 341                                         // If revision was hidden from sysops
 342                                         $rdel = Xml::tags( 'span', array( 'class'=>'mw-revdelundel-link' ), '('.wfMsgHtml( 'rev-delundel' ).')' );
 343                                 } else {
 344                                         $query = array(
 345                                                 'type' => 'revision',
 346                                                 'target' =>  $this->mNewRev->mTitle->getPrefixedDbkey(),
 347                                                 'ids' => $this->mNewRev->getId()
 348                                         );
 349                                         $rdel = $sk->revDeleteLink( $query, $this->mNewRev->isDeleted( Revision::DELETED_RESTRICTED ) );
 350                                 }
 351                                 $rdel = "&nbsp;&nbsp;&nbsp;$rdel ";
 352                         }
 353                 }
 354
 355                 $oldHeader = '<div id="mw-diff-otitle1"><strong>'.$this->mOldtitle.'</strong></div>' .
 356                         '<div id="mw-diff-otitle2">' . $sk->revUserTools( $this->mOldRev, !$this->unhide ) . "</div>" .
 357                         '<div id="mw-diff-otitle3">' . $oldminor . $sk->revComment( $this->mOldRev, !$diffOnly, !$this->unhide ).$ldel."</div>" .
 358                         '<div id="mw-diff-otitle4">' . $prevlink .'</div>';
 359                 $newHeader = '<div id="mw-diff-ntitle1"><strong>'.$this->mNewtitle.'</strong></div>' .
 360                         '<div id="mw-diff-ntitle2">' . $sk->revUserTools( $this->mNewRev, !$this->unhide ) . " $rollback</div>" .
 361                         '<div id="mw-diff-ntitle3">' . $newminor . $sk->revComment( $this->mNewRev, !$diffOnly, !$this->unhide ).$rdel."</div>" .
 362                         '<div id="mw-diff-ntitle4">' . $nextlink . $patrol . '</div>';
 363
 364                 # Check if this user can see the revisions
 365                 $allowed = $this->mOldRev->userCan(Revision::DELETED_TEXT)
 366                         && $this->mNewRev->userCan(Revision::DELETED_TEXT);
 367                 $deleted = $this->mOldRev->isDeleted(Revision::DELETED_TEXT)
 368                         || $this->mNewRev->isDeleted(Revision::DELETED_TEXT);
 369                 # Output the diff if allowed...
 370                 if( $deleted && (!$this->unhide || !$allowed) ) {
 371                         $this->showDiffStyle();
 372                         $multi = $this->getMultiNotice();
 373                         $wgOut->addHTML( $this->addHeader( '', $oldHeader, $newHeader, $multi ) );
 374                         if( !$allowed ) {
 375                                 # Give explanation for why revision is not visible
 376                                 $wgOut->wrapWikiMsg( "<div class='mw-warning plainlinks'>\n$1</div>\n",
 377                                         array( 'rev-deleted-no-diff' ) );
 378                         } else {
 379                                 # Give explanation and add a link to view the diff...
 380                                 $link = $this->mTitle->getFullUrl( array(
 381                                         'diff' => $this->mNewid,
 382                                         'oldid' => $this->mOldid,
 383                                         'unhide' => 1
 384                                 ) );
 385                                 $wgOut->wrapWikiMsg( "<div class='mw-warning plainlinks'>\n$1</div>\n",
 386                                         array( 'rev-deleted-unhide-diff', $link ) );
 387                         }
 388                 } else if( $wgEnableHtmlDiff && $this->htmldiff ) {
 389                         $multi = $this->getMultiNotice();
 390                         $wgOut->addHTML( '<div class="diff-switchtype">' . $sk->link(
 391                                 $this->mTitle,
 392                                 wfMsgHtml( 'wikicodecomparison' ),
 393                                 array(
 394                                         'id' => 'differences-switchtype'
 395                                 ),
 396                                 array(
 397                                         'diff' => $this->mNewid,
 398                                         'oldid' => $this->mOldid,
 399                                         'htmldiff' => 0
 400                                 ),
 401                                 array(
 402                                         'known',
 403                                         'noclasses'
 404                                 )
 405                         ) . '</div>');
 406                         $wgOut->addHTML( $this->addHeader( '', $oldHeader, $newHeader, $multi ) );
 407                         $this->renderHtmlDiff();
 408                 } else {
 409                         if( $wgEnableHtmlDiff ) {
 410                                 $wgOut->addHTML( '<div class="diff-switchtype">' . $sk->link(
 411                                         $this->mTitle,
 412                                         wfMsgHtml( 'visualcomparison' ),
 413                                         array(
 414                                                 'id' => 'differences-switchtype'
 415                                         ),
 416                                         array(
 417                                                 'diff' => $this->mNewid,
 418                                                 'oldid' => $this->mOldid,
 419                                                 'htmldiff' => 1
 420                                         ),
 421                                         array(
 422                                                 'known',
 423                                                 'noclasses'
 424                                         )
 425                                 ) . '</div>');
 426                         }
 427                         $this->showDiff( $oldHeader, $newHeader );
 428                         if( !$diffOnly ) {
 429                                 $this->renderNewRevision();
 430                         }
 431                 }
 432                 wfProfileOut( __METHOD__ );
 433         }
 434
 435         /**
 436          * Show the new revision of the page.
 437          */
 438         function renderNewRevision() {
 439                 global $wgOut, $wgUser;
 440                 wfProfileIn( __METHOD__ );
 441
 442                 $wgOut->addHTML( "<hr /><h2>{$this->mPagetitle}</h2>\n" );
 443                 # Add deleted rev tag if needed
 444                 if( !$this->mNewRev->userCan(Revision::DELETED_TEXT) ) {
 445                         $wgOut->wrapWikiMsg( "<div class='mw-warning plainlinks'>\n$1</div>\n", 'rev-deleted-text-permission' );
 446                 } else if( $this->mNewRev->isDeleted(Revision::DELETED_TEXT) ) {
 447                         $wgOut->wrapWikiMsg( "<div class='mw-warning plainlinks'>\n$1</div>\n", 'rev-deleted-text-view' );
 448                 }
 449
 450                 if( !$this->mNewRev->isCurrent() ) {
 451                         $oldEditSectionSetting = $wgOut->parserOptions()->setEditSection( false );
 452                 }
 453
 454                 $this->loadNewText();
 455                 if( is_object( $this->mNewRev ) ) {
 456                         $wgOut->setRevisionId( $this->mNewRev->getId() );
 457                 }
 458
 459                 if( $this->mTitle->isCssJsSubpage() || $this->mTitle->isCssOrJsPage() ) {
 460                         // Stolen from Article::view --AG 2007-10-11
 461                         // Give hooks a chance to customise the output
 462                         if( wfRunHooks( 'ShowRawCssJs', array( $this->mNewtext, $this->mTitle, $wgOut ) ) ) {
 463                                 // Wrap the whole lot in a <pre> and don't parse
 464                                 $m = array();
 465                                 preg_match( '!\.(css|js)$!u', $this->mTitle->getText(), $m );
 466                                 $wgOut->addHTML( "<pre class=\"mw-code mw-{$m[1]}\" dir=\"ltr\">\n" );
 467                                 $wgOut->addHTML( htmlspecialchars( $this->mNewtext ) );
 468                                 $wgOut->addHTML( "\n</pre>\n" );
 469                         }
 470                 } else {
 471                         $wgOut->addWikiTextTidy( $this->mNewtext );
 472                 }
 473
 474                 if( is_object( $this->mNewRev ) && !$this->mNewRev->isCurrent() ) {
 475                         $wgOut->parserOptions()->setEditSection( $oldEditSectionSetting );
 476                 }
 477                 # Add redundant patrol link on bottom...
 478                 if( $this->mRcidMarkPatrolled && $this->mTitle->quickUserCan('patrol') ) {
 479                         $sk = $wgUser->getSkin();
 480                         $wgOut->addHTML(
 481                                 "<div class='patrollink'>[" . $sk->link(
 482                                         $this->mTitle,
 483                                         wfMsgHtml( 'markaspatrolleddiff' ),
 484                                         array(),
 485                                         array(
 486                                                 'action' => 'markpatrolled',
 487                                                 'rcid' => $this->mRcidMarkPatrolled
 488                                         )
 489                                 ) . ']</div>'
 490                          );
 491                 }
 492
 493                 wfProfileOut( __METHOD__ );
 494         }
 495
 496
 497         function renderHtmlDiff() {
 498                 global $wgOut, $wgParser, $wgDebugComments;
 499                 wfProfileIn( __METHOD__ );
 500
 501                 $this->showDiffStyle();
 502
 503                 $wgOut->addHTML( '<h2>'.wfMsgHtml( 'visual-comparison' )."</h2>\n" );
 504                 #add deleted rev tag if needed
 505                 if( !$this->mNewRev->userCan(Revision::DELETED_TEXT) ) {
 506                         $wgOut->wrapWikiMsg( "<div class='mw-warning plainlinks'>\n$1</div>\n", 'rev-deleted-text-permission' );
 507                 } else if( $this->mNewRev->isDeleted(Revision::DELETED_TEXT) ) {
 508                         $wgOut->wrapWikiMsg( "<div class='mw-warning plainlinks'>\n$1</div>\n", 'rev-deleted-text-view' );
 509                 }
 510
 511                 if( !$this->mNewRev->isCurrent() ) {
 512                         $oldEditSectionSetting = $wgOut->parserOptions()->setEditSection( false );
 513                 }
 514
 515                 $this->loadText();
 516
 517                 // Old revision
 518                 if( is_object( $this->mOldRev ) ) {
 519                         $wgOut->setRevisionId( $this->mOldRev->getId() );
 520                 }
 521
 522                 $popts = $wgOut->parserOptions();
 523                 $oldTidy = $popts->setTidy( true );
 524                 $popts->setEditSection( false );
 525
 526                 $parserOutput = $wgParser->parse( $this->mOldtext, $this->getTitle(), $popts, true, true, $wgOut->getRevisionId() );
 527                 $popts->setTidy( $oldTidy );
 528
 529                 //only for new?
 530                 //$wgOut->addParserOutputNoText( $parserOutput );
 531                 $oldHtml = $parserOutput->getText();
 532                 wfRunHooks( 'OutputPageBeforeHTML', array( &$wgOut, &$oldHtml ) );
 533
 534                 // New revision
 535                 if( is_object( $this->mNewRev ) ) {
 536                         $wgOut->setRevisionId( $this->mNewRev->getId() );
 537                 }
 538
 539                 $popts = $wgOut->parserOptions();
 540                 $oldTidy = $popts->setTidy( true );
 541
 542                 $parserOutput = $wgParser->parse( $this->mNewtext, $this->getTitle(), $popts, true, true, $wgOut->getRevisionId() );
 543                 $popts->setTidy( $oldTidy );
 544
 545                 $wgOut->addParserOutputNoText( $parserOutput );
 546                 $newHtml = $parserOutput->getText();
 547                 wfRunHooks( 'OutputPageBeforeHTML', array( &$wgOut, &$newHtml ) );
 548
 549                 unset($parserOutput, $popts);
 550
 551                 $differ = new HTMLDiffer(new DelegatingContentHandler($wgOut));
 552                 $differ->htmlDiff($oldHtml, $newHtml);
 553                 if ( $wgDebugComments ) {
 554                         $wgOut->addHTML( "\n<!-- HtmlDiff Debug Output:\n" . HTMLDiffer::getDebugOutput() . " End Debug -->" );
 555                 }
 556
 557                 wfProfileOut( __METHOD__ );
 558         }
 559
 560         /**
 561          * Show the first revision of an article. Uses normal diff headers in
 562          * contrast to normal "old revision" display style.
 563          */
 564         function showFirstRevision() {
 565                 global $wgOut, $wgUser;
 566                 wfProfileIn( __METHOD__ );
 567
 568                 # Get article text from the DB
 569                 #
 570                 if ( ! $this->loadNewText() ) {
 571                         $t = $this->mTitle->getPrefixedText();
 572                         $d = wfMsgExt( 'missingarticle-diff', array( 'escape' ), $this->mOldid, $this->mNewid );
 573                         $wgOut->setPagetitle( wfMsg( 'errorpagetitle' ) );
 574                         $wgOut->addWikiMsg( 'missing-article', "<nowiki>$t</nowiki>", $d );
 575                         wfProfileOut( __METHOD__ );
 576                         return;
 577                 }
 578                 if ( $this->mNewRev->isCurrent() ) {
 579                         $wgOut->setArticleFlag( true );
 580                 }
 581
 582                 # Check if user is allowed to look at this page. If not, bail out.
 583                 #
 584                 if ( !$this->mTitle->userCanRead() ) {
 585                         $wgOut->loginToUse();
 586                         $wgOut->output();
 587                         wfProfileOut( __METHOD__ );
 588                         throw new MWException("Permission Error: you do not have access to view this page");
 589                 }
 590
 591                 # Prepare the header box
 592                 #
 593                 $sk = $wgUser->getSkin();
 594
 595                 $next = $this->mTitle->getNextRevisionID( $this->mNewid );
 596                 if( !$next ) {
 597                         $nextlink = '';
 598                 } else {
 599                         $nextlink = '<br/>' . $sk->link(
 600                                 $this->mTitle,
 601                                 wfMsgHtml( 'nextdiff' ),
 602                                 array(
 603                                         'id' => 'differences-nextlink'
 604                                 ),
 605                                 array(
 606                                         'diff' => 'next',
 607                                         'oldid' => $this->mNewid,
 608                                         $this->htmlDiffArgument()
 609                                 ),
 610                                 array(
 611                                         'known',
 612                                         'noclasses'
 613                                 )
 614                         );
 615                 }
 616                 $header = "<div class=\"firstrevisionheader\" style=\"text-align: center\">" .
 617                         $sk->revUserTools( $this->mNewRev ) . "<br/>" . $sk->revComment( $this->mNewRev ) . $nextlink . "</div>\n";
 618
 619                 $wgOut->addHTML( $header );
 620
 621                 $wgOut->setSubtitle( wfMsgExt( 'difference', array( 'parseinline' ) ) );
 622                 $wgOut->setRobotPolicy( 'noindex,nofollow' );
 623
 624                 wfProfileOut( __METHOD__ );
 625         }
 626
 627         function htmlDiffArgument(){
 628                 global $wgEnableHtmlDiff;
 629                 if($wgEnableHtmlDiff){
 630                         if($this->htmldiff){
 631                                 return array( 'htmldiff' => 1 );
 632                         }else{
 633                                 return array( 'htmldiff' => 0 );
 634                         }
 635                 }else{
 636                         return array();
 637                 }
 638         }
 639
 640         /**
 641          * Get the diff text, send it to $wgOut
 642          * Returns false if the diff could not be generated, otherwise returns true
 643          */
 644         function showDiff( $otitle, $ntitle ) {
 645                 global $wgOut;
 646                 $diff = $this->getDiff( $otitle, $ntitle );
 647                 if ( $diff === false ) {
 648                         $wgOut->addWikiMsg( 'missing-article', "<nowiki>(fixme, bug)</nowiki>", '' );
 649                         return false;
 650                 } else {
 651                         $this->showDiffStyle();
 652                         $wgOut->addHTML( $diff );
 653                         return true;
 654                 }
 655         }
 656
 657         /**
 658          * Add style sheets and supporting JS for diff display.
 659          */
 660         function showDiffStyle() {
 661                 global $wgStylePath, $wgStyleVersion, $wgOut;
 662                 $wgOut->addStyle( 'common/diff.css' );
 663
 664                 // JS is needed to detect old versions of Mozilla to work around an annoyance bug.
 665                 $wgOut->addScript( "<script type=\"text/javascript\" src=\"$wgStylePath/common/diff.js?$wgStyleVersion\"></script>" );
 666         }
 667
 668         /**
 669          * Get complete diff table, including header
 670          *
 671          * @param Title $otitle Old title
 672          * @param Title $ntitle New title
 673          * @return mixed
 674          */
 675         function getDiff( $otitle, $ntitle ) {
 676                 $body = $this->getDiffBody();
 677                 if ( $body === false ) {
 678                         return false;
 679                 } else {
 680                         $multi = $this->getMultiNotice();
 681                         return $this->addHeader( $body, $otitle, $ntitle, $multi );
 682                 }
 683         }
 684
 685         /**
 686          * Get the diff table body, without header
 687          *
 688          * @return mixed
 689          */
 690         function getDiffBody() {
 691                 global $wgMemc;
 692                 wfProfileIn( __METHOD__ );
 693                 $this->mCacheHit = true;
 694                 // Check if the diff should be hidden from this user
 695                 if ( !$this->loadRevisionData() )
 696                         return '';
 697                 if ( $this->mOldRev && !$this->mOldRev->userCan(Revision::DELETED_TEXT) ) {
 698                         return '';
 699                 } else if ( $this->mNewRev && !$this->mNewRev->userCan(Revision::DELETED_TEXT) ) {
 700                         return '';
 701                 } else if ( $this->mOldRev && $this->mNewRev && $this->mOldRev->getID() == $this->mNewRev->getID() ) {
 702                         return '';
 703                 }
 704                 // Cacheable?
 705                 $key = false;
 706                 if ( $this->mOldid && $this->mNewid ) {
 707                         $key = wfMemcKey( 'diff', 'version', MW_DIFF_VERSION, 'oldid', $this->mOldid, 'newid', $this->mNewid );
 708                         // Try cache
 709                         if ( !$this->mRefreshCache ) {
 710                                 $difftext = $wgMemc->get( $key );
 711                                 if ( $difftext ) {
 712                                         wfIncrStats( 'diff_cache_hit' );
 713                                         $difftext = $this->localiseLineNumbers( $difftext );
 714                                         $difftext .= "\n<!-- diff cache key $key -->\n";
 715                                         wfProfileOut( __METHOD__ );
 716                                         return $difftext;
 717                                 }
 718                         } // don't try to load but save the result
 719                 }
 720                 $this->mCacheHit = false;
 721
 722                 // Loadtext is permission safe, this just clears out the diff
 723                 if ( !$this->loadText() ) {
 724                         wfProfileOut( __METHOD__ );
 725                         return false;
 726                 }
 727
 728                 $difftext = $this->generateDiffBody( $this->mOldtext, $this->mNewtext );
 729
 730                 // Save to cache for 7 days
 731                 if ( !wfRunHooks( 'AbortDiffCache', array( &$this ) ) ) {
 732                         wfIncrStats( 'diff_uncacheable' );
 733                 } else if ( $key !== false && $difftext !== false ) {
 734                         wfIncrStats( 'diff_cache_miss' );
 735                         $wgMemc->set( $key, $difftext, 7*86400 );
 736                 } else {
 737                         wfIncrStats( 'diff_uncacheable' );
 738                 }
 739                 // Replace line numbers with the text in the user's language
 740                 if ( $difftext !== false ) {
 741                         $difftext = $this->localiseLineNumbers( $difftext );
 742                 }
 743                 wfProfileOut( __METHOD__ );
 744                 return $difftext;
 745         }
 746
 747         /**
 748          * Make sure the proper modules are loaded before we try to
 749          * make the diff
 750          */
 751         private function initDiffEngines() {
 752                 global $wgExternalDiffEngine;
 753                 if ( $wgExternalDiffEngine == 'wikidiff' && !function_exists( 'wikidiff_do_diff' ) ) {
 754                         wfProfileIn( __METHOD__ . '-php_wikidiff.so' );
 755                         wfSuppressWarnings();
 756                         dl( 'php_wikidiff.so' );
 757                         wfRestoreWarnings();
 758                         wfProfileOut( __METHOD__ . '-php_wikidiff.so' );
 759                 }
 760                 else if ( $wgExternalDiffEngine == 'wikidiff2' && !function_exists( 'wikidiff2_do_diff' ) ) {
 761                         wfProfileIn( __METHOD__ . '-php_wikidiff2.so' );
 762                         wfSuppressWarnings();
 763                         dl( 'php_wikidiff2.so' );
 764                         wfRestoreWarnings();
 765                         wfProfileOut( __METHOD__ . '-php_wikidiff2.so' );
 766                 }
 767         }
 768
 769         /**
 770          * Generate a diff, no caching
 771          * $otext and $ntext must be already segmented
 772          */
 773         function generateDiffBody( $otext, $ntext ) {
 774                 global $wgExternalDiffEngine, $wgContLang;
 775
 776                 $otext = str_replace( "\r\n", "\n", $otext );
 777                 $ntext = str_replace( "\r\n", "\n", $ntext );
 778
 779                 $this->initDiffEngines();
 780
 781                 if ( $wgExternalDiffEngine == 'wikidiff' && function_exists( 'wikidiff_do_diff' ) ) {
 782                         # For historical reasons, external diff engine expects
 783                         # input text to be HTML-escaped already
 784                         $otext = htmlspecialchars ( $wgContLang->segmentForDiff( $otext ) );
 785                         $ntext = htmlspecialchars ( $wgContLang->segmentForDiff( $ntext ) );
 786                         return $wgContLang->unsegementForDiff( wikidiff_do_diff( $otext, $ntext, 2 ) ) .
 787                         $this->debug( 'wikidiff1' );
 788                 }
 789
 790                 if ( $wgExternalDiffEngine == 'wikidiff2' && function_exists( 'wikidiff2_do_diff' ) ) {
 791                         # Better external diff engine, the 2 may some day be dropped
 792                         # This one does the escaping and segmenting itself
 793                         wfProfileIn( 'wikidiff2_do_diff' );
 794                         $text = wikidiff2_do_diff( $otext, $ntext, 2 );
 795                         $text .= $this->debug( 'wikidiff2' );
 796                         wfProfileOut( 'wikidiff2_do_diff' );
 797                         return $text;
 798                 }
 799                 if ( $wgExternalDiffEngine != 'wikidiff3' && $wgExternalDiffEngine !== false ) {
 800                         # Diff via the shell
 801                         global $wgTmpDirectory;
 802                         $tempName1 = tempnam( $wgTmpDirectory, 'diff_' );
 803                         $tempName2 = tempnam( $wgTmpDirectory, 'diff_' );
 804
 805                         $tempFile1 = fopen( $tempName1, "w" );
 806                         if ( !$tempFile1 ) {
 807                                 wfProfileOut( __METHOD__ );
 808                                 return false;
 809                         }
 810                         $tempFile2 = fopen( $tempName2, "w" );
 811                         if ( !$tempFile2 ) {
 812                                 wfProfileOut( __METHOD__ );
 813                                 return false;
 814                         }
 815                         fwrite( $tempFile1, $otext );
 816                         fwrite( $tempFile2, $ntext );
 817                         fclose( $tempFile1 );
 818                         fclose( $tempFile2 );
 819                         $cmd = wfEscapeShellArg( $wgExternalDiffEngine, $tempName1, $tempName2 );
 820                         wfProfileIn( __METHOD__ . "-shellexec" );
 821                         $difftext = wfShellExec( $cmd );
 822                         $difftext .= $this->debug( "external $wgExternalDiffEngine" );
 823                         wfProfileOut( __METHOD__ . "-shellexec" );
 824                         unlink( $tempName1 );
 825                         unlink( $tempName2 );
 826                         return $difftext;
 827                 }
 828
 829                 # Native PHP diff
 830                 $ota = explode( "\n", $wgContLang->segmentForDiff( $otext ) );
 831                 $nta = explode( "\n", $wgContLang->segmentForDiff( $ntext ) );
 832                 $diffs = new Diff( $ota, $nta );
 833                 $formatter = new TableDiffFormatter();
 834                 return $wgContLang->unsegmentForDiff( $formatter->format( $diffs ) ) .
 835                 $this->debug();
 836         }
 837
 838         /**
 839          * Generate a debug comment indicating diff generating time,
 840          * server node, and generator backend.
 841          */
 842         protected function debug( $generator="internal" ) {
 843                 global $wgShowHostnames;
 844                 if ( !$this->enableDebugComment ) {
 845                         return '';
 846                 }
 847                 $data = array( $generator );
 848                 if( $wgShowHostnames ) {
 849                         $data[] = wfHostname();
 850                 }
 851                 $data[] = wfTimestamp( TS_DB );
 852                 return "<!-- diff generator: " .
 853                 implode( " ",
 854                 array_map(
 855                                         "htmlspecialchars",
 856                 $data ) ) .
 857                         " -->\n";
 858         }
 859
 860         /**
 861          * Replace line numbers with the text in the user's language
 862          */
 863         function localiseLineNumbers( $text ) {
 864                 return preg_replace_callback( '/<!--LINE (\d+)-->/',
 865                 array( &$this, 'localiseLineNumbersCb' ), $text );
 866         }
 867
 868         function localiseLineNumbersCb( $matches ) {
 869                 global $wgLang;
 870                 if ( $matches[1] === '1' && $this->mReducedLineNumbers ) return '';
 871                 return wfMsgExt( 'lineno', 'escape', $wgLang->formatNum( $matches[1] ) );
 872         }
 873
 874
 875         /**
 876          * If there are revisions between the ones being compared, return a note saying so.
 877          */
 878         function getMultiNotice() {
 879                 if ( !is_object($this->mOldRev) || !is_object($this->mNewRev) )
 880                 return '';
 881
 882                 if( !$this->mOldPage->equals( $this->mNewPage ) ) {
 883                         // Comparing two different pages? Count would be meaningless.
 884                         return '';
 885                 }
 886
 887                 $oldid = $this->mOldRev->getId();
 888                 $newid = $this->mNewRev->getId();
 889                 if ( $oldid > $newid ) {
 890                         $tmp = $oldid; $oldid = $newid; $newid = $tmp;
 891                 }
 892
 893                 $n = $this->mTitle->countRevisionsBetween( $oldid, $newid );
 894                 if ( !$n )
 895                 return '';
 896
 897                 return wfMsgExt( 'diff-multi', array( 'parseinline' ), $n );
 898         }
 899
 900
 901         /**
 902          * Add the header to a diff body
 903          */
 904         static function addHeader( $diff, $otitle, $ntitle, $multi = '' ) {
 905                 $colspan = 1;
 906                 $header = "<table class='diff'>";
 907                 if( $diff ) { // Safari/Chrome show broken output if cols not used
 908                         $header .= "
 909                         <col class='diff-marker' />
 910                         <col class='diff-content' />
 911                         <col class='diff-marker' />
 912                         <col class='diff-content' />";
 913                         $colspan = 2;
 914                 }
 915                 $header .= "
 916                 <tr valign='top'>
 917                 <td colspan='$colspan' class='diff-otitle'>{$otitle}</td>
 918                 <td colspan='$colspan' class='diff-ntitle'>{$ntitle}</td>
 919                 </tr>";
 920
 921                 if ( $multi != '' )
 922                 $header .= "<tr><td colspan='4' align='center' class='diff-multi'>{$multi}</td></tr>";
 923
 924                 return $header . $diff . "</table>";
 925         }
 926
 927         /**
 928          * Use specified text instead of loading from the database
 929          */
 930         function setText( $oldText, $newText ) {
 931                 $this->mOldtext = $oldText;
 932                 $this->mNewtext = $newText;
 933                 $this->mTextLoaded = 2;
 934                 $this->mRevisionsLoaded = true;
 935         }
 936
 937         /**
 938          * Load revision metadata for the specified articles. If newid is 0, then compare
 939          * the old article in oldid to the current article; if oldid is 0, then
 940          * compare the current article to the immediately previous one (ignoring the
 941          * value of newid).
 942          *
 943          * If oldid is false, leave the corresponding revision object set
 944          * to false. This is impossible via ordinary user input, and is provided for
 945          * API convenience.
 946          */
 947         function loadRevisionData() {
 948                 global $wgLang, $wgUser;
 949                 if ( $this->mRevisionsLoaded ) {
 950                         return true;
 951                 } else {
 952                         // Whether it succeeds or fails, we don't want to try again
 953                         $this->mRevisionsLoaded = true;
 954                 }
 955
 956                 // Load the new revision object
 957                 $this->mNewRev = $this->mNewid
 958                         ? Revision::newFromId( $this->mNewid )
 959                         : Revision::newFromTitle( $this->mTitle );
 960                 if( !$this->mNewRev instanceof Revision )
 961                         return false;
 962
 963                 // Update the new revision ID in case it was 0 (makes life easier doing UI stuff)
 964                 $this->mNewid = $this->mNewRev->getId();
 965
 966                 // Check if page is editable
 967                 $editable = $this->mNewRev->getTitle()->userCan( 'edit' );
 968
 969                 // Set assorted variables
 970                 $timestamp = $wgLang->timeanddate( $this->mNewRev->getTimestamp(), true );
 971                 $dateofrev = $wgLang->date( $this->mNewRev->getTimestamp(), true );
 972                 $timeofrev = $wgLang->time( $this->mNewRev->getTimestamp(), true );
 973                 $this->mNewPage = $this->mNewRev->getTitle();
 974                 if( $this->mNewRev->isCurrent() ) {
 975                         $newLink = $this->mNewPage->escapeLocalUrl( array(
 976                                 'oldid' => $this->mNewid
 977                         ) );
 978                         $this->mPagetitle = htmlspecialchars( wfMsg(
 979                                 'currentrev-asof',
 980                                 $timestamp,
 981                                 $dateofrev,
 982                                 $timeofrev
 983                         ) );
 984                         $newEdit = $this->mNewPage->escapeLocalUrl( array(
 985                                 'action' => 'edit'
 986                         ) );
 987
 988                         $this->mNewtitle = "<a href='$newLink'>{$this->mPagetitle}</a>";
 989                         $this->mNewtitle .= " (<a href='$newEdit'>" . wfMsgHtml( $editable ? 'editold' : 'viewsourceold' ) . "</a>)";
 990                 } else {
 991                         $newLink = $this->mNewPage->escapeLocalUrl( array(
 992                                 'oldid' => $this->mNewid
 993                         ) );
 994                         $newEdit = $this->mNewPage->escapeLocalUrl( array(
 995                                 'action' => 'edit',
 996                                 'oldid' => $this->mNewid
 997                         ) );
 998                         $this->mPagetitle = htmlspecialchars( wfMsg(
 999                                 'revisionasof',
1000                                 $timestamp,
1001                                 $dateofrev,
1002                                 $timeofrev
1003                         ) );
1004
1005                         $this->mNewtitle = "<a href='$newLink'>{$this->mPagetitle}</a>";
1006                         $this->mNewtitle .= " (<a href='$newEdit'>" . wfMsgHtml( $editable ? 'editold' : 'viewsourceold' ) . "</a>)";
1007                 }
1008                 if( !$this->mNewRev->userCan(Revision::DELETED_TEXT) ) {
1009                         $this->mNewtitle = "<span class='history-deleted'>{$this->mPagetitle}</span>";
1010                 } else if ( $this->mNewRev->isDeleted(Revision::DELETED_TEXT) ) {
1011                         $this->mNewtitle = "<span class='history-deleted'>{$this->mNewtitle}</span>";
1012                 }
1013
1014                 // Load the old revision object
1015                 $this->mOldRev = false;
1016                 if( $this->mOldid ) {
1017                         $this->mOldRev = Revision::newFromId( $this->mOldid );
1018                 } elseif ( $this->mOldid === 0 ) {
1019                         $rev = $this->mNewRev->getPrevious();
1020                         if( $rev ) {
1021                                 $this->mOldid = $rev->getId();
1022                                 $this->mOldRev = $rev;
1023                         } else {
1024                                 // No previous revision; mark to show as first-version only.
1025                                 $this->mOldid = false;
1026                                 $this->mOldRev = false;
1027                         }
1028                 }/* elseif ( $this->mOldid === false ) leave mOldRev false; */
1029
1030                 if( is_null( $this->mOldRev ) ) {
1031                         return false;
1032                 }
1033
1034                 if ( $this->mOldRev ) {
1035                         $this->mOldPage = $this->mOldRev->getTitle();
1036
1037                         $t = $wgLang->timeanddate( $this->mOldRev->getTimestamp(), true );
1038                         $dateofrev = $wgLang->date( $this->mOldRev->getTimestamp(), true );
1039                         $timeofrev = $wgLang->time( $this->mOldRev->getTimestamp(), true );
1040                         $oldLink = $this->mOldPage->escapeLocalUrl( array(
1041                                 'oldid' => $this->mOldid
1042                         ) );
1043                         $oldEdit = $this->mOldPage->escapeLocalUrl( array(
1044                                 'action' => 'edit',
1045                                 'oldid' => $this->mOldid
1046                         ) );
1047                         $this->mOldPagetitle = htmlspecialchars( wfMsg( 'revisionasof', $t, $dateofrev, $timeofrev ) );
1048
1049                         $this->mOldtitle = "<a href='$oldLink'>{$this->mOldPagetitle}</a>"
1050                         . " (<a href='$oldEdit'>" . wfMsgHtml( $editable ? 'editold' : 'viewsourceold' ) . "</a>)";
1051                         // Add an "undo" link
1052                         $newUndo = $this->mNewPage->escapeLocalUrl( array(
1053                                 'action' => 'edit',
1054                                 'undoafter' => $this->mOldid,
1055                                 'undo' => $this->mNewid
1056                         ) );
1057                         $htmlLink = htmlspecialchars( wfMsg( 'editundo' ) );
1058                         $htmlTitle = $wgUser->getSkin()->tooltip( 'undo' );
1059                         if( $editable && !$this->mOldRev->isDeleted( Revision::DELETED_TEXT ) && !$this->mNewRev->isDeleted( Revision::DELETED_TEXT ) ) {
1060                                 $this->mNewtitle .= " (<a href='$newUndo' $htmlTitle>" . $htmlLink . "</a>)";
1061                         }
1062
1063                         if( !$this->mOldRev->userCan( Revision::DELETED_TEXT ) ) {
1064                                 $this->mOldtitle = '<span class="history-deleted">' . $this->mOldPagetitle . '</span>';
1065                         } else if( $this->mOldRev->isDeleted( Revision::DELETED_TEXT ) ) {
1066                                 $this->mOldtitle = '<span class="history-deleted">' . $this->mOldtitle . '</span>';
1067                         }
1068                 }
1069
1070                 return true;
1071         }
1072
1073         /**
1074          * Load the text of the revisions, as well as revision data.
1075          */
1076         function loadText() {
1077                 if ( $this->mTextLoaded == 2 ) {
1078                         return true;
1079                 } else {
1080                         // Whether it succeeds or fails, we don't want to try again
1081                         $this->mTextLoaded = 2;
1082                 }
1083
1084                 if ( !$this->loadRevisionData() ) {
1085                         return false;
1086                 }
1087                 if ( $this->mOldRev ) {
1088                         $this->mOldtext = $this->mOldRev->getText( Revision::FOR_THIS_USER );
1089                         if ( $this->mOldtext === false ) {
1090                                 return false;
1091                         }
1092                 }
1093                 if ( $this->mNewRev ) {
1094                         $this->mNewtext = $this->mNewRev->getText( Revision::FOR_THIS_USER );
1095                         if ( $this->mNewtext === false ) {
1096                                 return false;
1097                         }
1098                 }
1099                 return true;
1100         }
1101
1102         /**
1103          * Load the text of the new revision, not the old one
1104          */
1105         function loadNewText() {
1106                 if ( $this->mTextLoaded >= 1 ) {
1107                         return true;
1108                 } else {
1109                         $this->mTextLoaded = 1;
1110                 }
1111                 if ( !$this->loadRevisionData() ) {
1112                         return false;
1113                 }
1114                 $this->mNewtext = $this->mNewRev->getText( Revision::FOR_THIS_USER );
1115                 return true;
1116         }
1117 }