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