env = $options['env']; $this->wts = new WikitextSerializer( $options ); $this->selserData = $options['selserData']; // Debug options $this->trace = $this->env->hasTraceFlag( 'selser' ); // Performance Timing option $this->metrics = $this->env->getSiteConfig()->metrics(); } /** * Wrap text node children of nodes with name $nodeName in tags and * compute the DSR values for those span tags. * * This helps DOMDiff mark up diffs of content in these nodes at a more fine-grained level. * * These DSR values rely on availability of information about trimmed leading * and trailing WS in these nodes in the wt->html direction. Given this info, * on the original unedited DOM, the computed DSR values for span tags wrapping * text nodes will be accurate. * * However, for the edited DOM with modified nodes, the computation is necessarily * speculative and as such, the computed DSR values may be bogus. Given this, * we rely on DOMDiff to diff the data-parsoid attribute and mark these nodes as * modified because of the mismatched dsr values. If so, these span tags will never * have selser reuse apply to them and the speculatively computed DSR values will * be discarded. * * @param Element $body * @param string $nodeName */ private function wrapTextChildrenOfNode( Element $body, string $nodeName ): void { // Note that while it might seem that only the first and last child need to be // wrapped, when nested list items are added, the previously last child of // a list item become an intermediate child in the new DOM. Without the span // wrapper, trailing trimmed whitespace gets dropped. $inListItem = isset( Consts::$HTML['ListItemTags'][$nodeName] ); foreach ( DOMCompat::querySelectorAll( $body, $nodeName ) as $elt ) { if ( WTUtils::isLiteralHTMLNode( $elt ) ) { continue; } // Skip items with about id => part of templates / extensions like Cite // CAVEAT: In some cases, this might be bailing out a little too early. // For example, where certain extensions might actually support nested DSR // values inside and where

items in them might benefit. But, given that // so far, such extensions are more the exception than the norm, we will take // the easy way out here and revisit this if dirty diffs for those

items // merit further action in the future. if ( $elt->hasAttribute( 'about' ) ) { continue; } // No point wrapping text nodes if there is no usable DSR $eltDSR = DOMDataUtils::getDataParsoid( $elt )->dsr ?? null; if ( !Utils::isValidDSR( $eltDSR ) ) { continue; } $doc = $body->ownerDocument; $firstChild = $c = $elt->firstChild; $start = $eltDSR->innerStart(); while ( $c ) { if ( $eltDSR && $c === $firstChild ) { if ( $eltDSR->leadingWS < 0 ) { // We don't have accurate information about the length of trimmed WS. // So, we cannot wrap this text node with a . break; } else { $start += $eltDSR->leadingWS; } } $next = $c->nextSibling; if ( $c instanceof Text ) { $text = $c->nodeValue; $len = strlen( $text ); // Don't wrap newlines since single-line-context handling will convert these // newlines into spaces and introduce dirty-diffs. Leaving nls outside the // wrapped text lets it be handled as separator text and emitted appropriately. if ( $len > 0 && $text[$len - 1] === "\n" ) { $text = rtrim( $text, "\n" ); $numOfNls = $len - strlen( $text ); $nl = str_repeat( "\n", $numOfNls ); $len -= $numOfNls; } else { $nl = null; // Detect last child of "original" item and tack on trailingWS width // to the contents of this text node. If this is a list item and // we added a nested list, that nested list will be the last item. // // Note that trailingWS is only captured for the last line, so if // the text ends in a newline (the "if" condition), we shouldn't need // to do this. if ( $eltDSR && ( !$next || ( $inListItem && DOMUtils::isList( $next ) && WTUtils::isNewElt( $next ) ) ) ) { $len += $eltDSR->trailingWS; } } $span = $doc->createElement( 'span' ); $span->setAttribute( 'data-mw-selser-wrapper', '' ); $dp = DOMDataUtils::getDataParsoid( $span ); $dp->dsr = new DomSourceRange( $start, $start + $len, 0, 0 ); $start += $len; if ( $nl ) { $elt->insertBefore( $span, $c ); $span->appendChild( $doc->createTextNode( $text ) ); $c->nodeValue = $nl; // @phan-suppress-next-line PhanPossiblyUndeclaredVariable $start += $numOfNls; } else { $elt->replaceChild( $span, $c ); $span->appendChild( $c ); } } elseif ( $c instanceof Comment ) { $start += WTUtils::decodedCommentLength( $c ); } elseif ( $c instanceof Element ) { // No point wrapping following text nodes if there won't be any usable DSR $cDSR = DOMDataUtils::getDataParsoid( $c )->dsr ?? null; if ( !Utils::isValidDSR( $cDSR ) ) { break; } $start = $cDSR->end; $next = $c->hasAttribute( 'about' ) ? WTUtils::skipOverEncapsulatedContent( $c ) : $next; } $c = $next; } } } /** * @param Element $body */ private function preprocessDOM( Element $body ): void { if ( Semver::satisfies( $this->env->getInputContentVersion(), '>=2.1.2' ) ) { // Wrap text node children of

elements in dummy spans $this->wrapTextChildrenOfNode( $body, 'li' ); $this->wrapTextChildrenOfNode( $body, 'dd' ); } } /** * Selectively serialize an HTML DOM. * * WARNING: You probably want to use WikitextContentModelHandler::fromDOM instead. * * @param Document $doc * @return string */ public function serializeDOM( Document $doc ): string { $serializeStart = null; $domDiffStart = null; $r = null; $timing = Timing::start( $this->metrics ); $body = DOMCompat::getBody( $doc ); $oldBody = DOMCompat::getBody( $this->selserData->oldDOM ); // Preprocess DOMs $this->preprocessDOM( $oldBody ); $this->preprocessDOM( $body ); // Use provided diff-marked DOM (used during testing) // or generate one (used in production) if ( $this->env->getDOMDiff() ) { $diff = [ 'isEmpty' => false ]; $body = DOMCompat::getBody( $this->env->getDOMDiff() ); } else { $domDiffTiming = Timing::start( $this->metrics ); $diff = ( new DOMDiff( $this->env ) )->diff( $oldBody, $body ); $domDiffTiming->end( 'html2wt.selser.domDiff' ); } if ( $diff['isEmpty'] ) { // Nothing was modified, just re-use the original source $r = $this->selserData->oldText; } else { if ( $this->trace || $this->env->hasDumpFlag( 'dom:post-dom-diff' ) ) { $options = [ 'storeDiffMark' => true ]; $this->env->writeDump( ContentUtils::dumpDOM( $oldBody, 'OLD DOM ', $options ) . "\n" . ContentUtils::dumpDOM( $body, 'DOM after running DOMDiff', $options ) ); } // Call the WikitextSerializer to do our bidding $r = $this->wts->serializeDOM( $doc, true ); } $timing->end( 'html2wt.selser.serialize' ); return $r; } }