mediawiki-extensions-Discus.../includes/CommentUtils.php

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<?php
namespace MediaWiki\Extension\DiscussionTools;
use DOMComment;
use DOMElement;
use DOMNode;
use DOMXPath;
use MediaWiki\MediaWikiServices;
use Title;
use Wikimedia\Parsoid\Utils\DOMCompat;
class CommentUtils {
private function __construct() {
}
private static $blockElementTypes = [
'div', 'p',
// Tables
'table', 'tbody', 'thead', 'tfoot', 'caption', 'th', 'tr', 'td',
// Lists
'ul', 'ol', 'li', 'dl', 'dt', 'dd',
// HTML5 heading content
'h1', 'h2', 'h3', 'h4', 'h5', 'h6', 'hgroup',
// HTML5 sectioning content
'article', 'aside', 'body', 'nav', 'section', 'footer', 'header', 'figure',
'figcaption', 'fieldset', 'details', 'blockquote',
// Other
'hr', 'button', 'canvas', 'center', 'col', 'colgroup', 'embed',
'map', 'object', 'pre', 'progress', 'video'
];
/**
* @param DOMNode $node
* @return bool Node is a block element
*/
public static function isBlockElement( DOMNode $node ) : bool {
return $node instanceof DOMElement &&
in_array( strtolower( $node->tagName ), self::$blockElementTypes );
}
private const SOL_TRANSPARENT_LINK_REGEX =
'/(?:^|\s)mw:PageProp\/(?:Category|redirect|Language)(?=$|\s)/D';
/**
* @param DOMNode $node
* @return bool Node is considered a rendering-transparent node in Parsoid
*/
public static function isRenderingTransparentNode( DOMNode $node ) : bool {
return (
$node instanceof DOMComment ||
$node instanceof DOMElement && (
strtolower( $node->tagName ) === 'meta' ||
(
strtolower( $node->tagName ) === 'link' &&
preg_match( self::SOL_TRANSPARENT_LINK_REGEX, $node->getAttribute( 'rel' ) ?? '' )
) ||
// Empty inline templates, e.g. tracking templates
(
strtolower( $node->tagName ) === 'span' &&
in_array( 'mw:Transclusion', explode( ' ', $node->getAttribute( 'typeof' ) ?? '' ) ) &&
!self::htmlTrim( DOMCompat::getInnerHTML( $node ) )
)
)
);
}
/**
* Elements which can't have element children (but some may have text content).
* https://html.spec.whatwg.org/#elements-2
* @var string[]
*/
private static $noElementChildrenElementTypes = [
// Void elements
'area', 'base', 'br', 'col', 'embed', 'hr', 'img', 'input',
'link', 'meta', 'param', 'source', 'track', 'wbr',
// Raw text elements
'script', 'style',
// Escapable raw text elements
'textarea', 'title',
];
/**
* @param DOMNode $node
* @return bool If true, node can't have element children. If false, it's complicated.
*/
public static function cantHaveElementChildren( DOMNode $node ) : bool {
return (
$node instanceof DOMComment ||
$node instanceof DOMElement &&
in_array( strtolower( $node->tagName ), self::$noElementChildrenElementTypes )
);
}
/**
* Get the index of $child in its parent
*
* @param DOMNode $child
* @return int
*/
public static function childIndexOf( DOMNode $child ) : int {
$i = 0;
while ( ( $child = $child->previousSibling ) ) {
$i++;
}
return $i;
}
/**
* Check whether a DOMNode contains (is an ancestor of) another DOMNode (or is the same node)
*
* @param DOMNode $ancestor
* @param DOMNode $descendant
* @return bool
*/
public static function contains( DOMNode $ancestor, DOMNode $descendant ) : bool {
// TODO can we use DOMNode->compareDocumentPosition() here maybe?
$node = $descendant;
while ( $node && $node !== $ancestor ) {
$node = $node->parentNode;
}
return $node === $ancestor;
}
/**
* Find closest ancestor element using one of the given tag names.
*
* @param DOMNode $node
* @param string[] $tagNames
* @return DOMElement|null
*/
public static function closestElement( DOMNode $node, array $tagNames ) : ?DOMElement {
do {
if (
$node->nodeType === XML_ELEMENT_NODE &&
in_array( strtolower( $node->nodeName ), $tagNames )
) {
return $node;
}
$node = $node->parentNode;
} while ( $node );
return null;
}
/**
* Find the transclusion node which rendered the current node, if it exists.
*
* 1. Find the closest ancestor with an 'about' attribute
* 2. Find the main node of the about-group (first sibling with the same 'about' attribute)
* 3. If this is an mw:Transclusion node, return it; otherwise, go to step 1
*
* @param DOMNode $node
* @return DOMElement|null Translcusion node, null if not found
*/
public static function getTranscludedFromElement( DOMNode $node ) : ?DOMElement {
while ( $node ) {
// 1.
if (
$node instanceof DOMElement &&
$node->getAttribute( 'about' ) &&
preg_match( '/^#mwt\d+$/', $node->getAttribute( 'about' ) )
) {
$about = $node->getAttribute( 'about' );
// 2.
while (
( $previousSibling = $node->previousSibling ) &&
$previousSibling instanceof DOMElement &&
$previousSibling->getAttribute( 'about' ) === $about
) {
$node = $previousSibling;
}
// 3.
if (
$node->getAttribute( 'typeof' ) &&
in_array( 'mw:Transclusion', explode( ' ', $node->getAttribute( 'typeof' ) ) )
) {
break;
}
}
$node = $node->parentNode;
}
return $node;
}
/**
* Given a heading node, return the node on which the ID attribute is set.
*
* Also returns the offset within that node where the heading text starts.
*
* @param DOMElement $heading Heading node (`<h1>`-`<h6>`)
* @return array Array containing a 'node' (DOMElement) and offset (int)
*/
public static function getHeadlineNodeAndOffset( DOMElement $heading ) : array {
// This code assumes that $wgFragmentMode is [ 'html5', 'legacy' ] or [ 'html5' ]
$headline = $heading;
$offset = 0;
if ( $headline->getAttribute( 'data-mw-comment-start' ) ) {
$headline = $headline->parentNode;
}
if ( !$headline->getAttribute( 'id' ) ) {
// PHP HTML: Find the child with .mw-headline
$headline = $headline->firstChild;
while (
$headline && !(
$headline instanceof DOMElement && $headline->getAttribute( 'class' ) === 'mw-headline'
)
) {
$headline = $headline->nextSibling;
}
if ( $headline ) {
if (
( $firstChild = $headline->firstChild ) instanceof DOMElement &&
$firstChild->getAttribute( 'class' ) === 'mw-headline-number'
) {
$offset = 1;
}
} else {
$headline = $heading;
}
}
return [
'node' => $headline,
'offset' => $offset,
];
}
/**
* Trim ASCII whitespace, as defined in the HTML spec.
*
* @param string $str
* @return string
*/
public static function htmlTrim( string $str ) : string {
// https://infra.spec.whatwg.org/#ascii-whitespace
return trim( $str, "\t\n\f\r " );
}
/**
* Get the indent level of $node, relative to $rootNode.
*
* The indent level is the number of lists inside of which it is nested.
*
* @param DOMNode $node
* @param DOMNode $rootNode
* @return int
*/
public static function getIndentLevel( DOMNode $node, DOMNode $rootNode ) : int {
$indent = 0;
while ( $node ) {
if ( $node === $rootNode ) {
break;
}
$nodeName = strtolower( $node->nodeName );
if ( $nodeName === 'li' || $nodeName === 'dd' ) {
$indent++;
}
$node = $node->parentNode;
}
return $indent;
}
/**
* Get an array of sibling nodes that contain parts of the given thread item.
*
* @param ThreadItem $item
* @return DOMElement[]
*/
private static function getCoveredSiblings( ThreadItem $item ) : array {
$range = $item->getRange();
$ancestor = $range->commonAncestorContainer;
// Convert to array early because apparently DOMNodeList acts like a linked list
// and accessing items by index is slow
$siblings = iterator_to_array( $ancestor->childNodes );
$start = 0;
$end = count( $siblings ) - 1;
// Find first of the siblings that contains the item
if ( $ancestor === $range->startContainer ) {
$start = $range->startOffset;
} else {
while ( !self::contains( $siblings[ $start ], $range->startContainer ) ) {
$start++;
}
}
// Find last of the siblings that contains the item
if ( $ancestor === $range->endContainer ) {
$end = $range->endOffset - 1;
} else {
while ( !self::contains( $siblings[ $end ], $range->endContainer ) ) {
$end--;
}
}
return array_slice( $siblings, $start, $end - $start + 1 );
}
/**
* Get the nodes (if any) that contain the given thread item, and nothing else.
*
* @param ThreadItem $item
* @return DOMElement[]|null
*/
public static function getFullyCoveredSiblings( ThreadItem $item ) : ?array {
$siblings = self::getCoveredSiblings( $item );
$startContainer = $item->getRange()->startContainer;
$endContainer = $item->getRange()->endContainer;
$startOffset = $item->getRange()->startOffset;
$endOffset = $item->getRange()->endOffset;
$isIgnored = function ( $node ) {
// Ignore empty text nodes
return $node->nodeType === XML_TEXT_NODE && CommentUtils::htmlTrim( $node->nodeValue ) === '';
};
$isFirstNonemptyChild = function ( $node ) use ( $isIgnored ) {
while ( ( $node = $node->previousSibling ) ) {
if ( !$isIgnored( $node ) ) {
return false;
}
}
return true;
};
$isLastNonemptyChild = function ( $node ) use ( $isIgnored ) {
while ( ( $node = $node->nextSibling ) ) {
if ( !$isIgnored( $node ) ) {
return false;
}
}
return true;
};
$startMatches = false;
$node = $siblings[ 0 ] ?? null;
while ( $node ) {
if ( $startContainer->childNodes && $startContainer->childNodes[ $startOffset ] === $node ) {
$startMatches = true;
break;
}
if ( $startContainer === $node && $startOffset === 0 ) {
$startMatches = true;
break;
}
if ( $isIgnored( $node ) ) {
$node = $node->nextSibling;
} else {
$node = $node->firstChild;
}
}
$endMatches = false;
$node = end( $siblings );
while ( $node ) {
if ( $endContainer->childNodes && $endContainer->childNodes[ $endOffset - 1 ] === $node ) {
$endMatches = true;
break;
}
$length = ( $node->nodeType === XML_TEXT_NODE ) ?
strlen( rtrim( $node->nodeValue, "\t\n\f\r " ) ) :
// PHP bug: childNodes can be null for comment nodes
// (it should always be a DOMNodeList, even if the node can't have children)
( $node->childNodes ? $node->childNodes->length : 0 );
if ( $endContainer === $node && $endOffset === $length ) {
$endMatches = true;
break;
}
if ( $isIgnored( $node ) ) {
$node = $node->previousSibling;
} else {
$node = $node->lastChild;
}
}
if ( $startMatches && $endMatches ) {
// If these are all of the children (or the only child), go up one more level
while (
( $parent = $siblings[ 0 ]->parentNode ) &&
$isFirstNonemptyChild( $siblings[ 0 ] ) &&
$isLastNonemptyChild( end( $siblings ) )
) {
$siblings = [ $parent ];
}
return $siblings;
}
return null;
}
/**
* Unwrap Parsoid sections
*
* @param DOMElement $element Parent element, e.g. document body
* @param string|null $keepSection Section to keep
*/
public static function unwrapParsoidSections(
DOMElement $element, string $keepSection = null
) : void {
$xpath = new DOMXPath( $element->ownerDocument );
$sections = $xpath->query( '//section[@data-mw-section-id]', $element );
foreach ( $sections as $section ) {
$parent = $section->parentNode;
$sectionId = $section->getAttribute( 'data-mw-section-id' );
// Copy section ID to first child (should be a heading)
if ( $sectionId !== '' && intval( $sectionId ) > 0 ) {
$section->firstChild->setAttribute( 'data-mw-section-id', $sectionId );
}
if ( $keepSection !== null && $sectionId === $keepSection ) {
return;
}
while ( $section->firstChild ) {
$parent->insertBefore( $section->firstChild, $section );
}
$parent->removeChild( $section );
}
}
/**
* Get a MediaWiki page title from a URL
*
* @param string $url
* @return Title|null
*/
public static function getTitleFromUrl( string $url ) : ?Title {
$bits = parse_url( $url );
$query = wfCgiToArray( $bits['query'] ?? '' );
if ( isset( $query['title'] ) ) {
return Title::newFromText( $query['title'] );
}
$config = MediaWikiServices::getInstance()->getMainConfig();
// TODO: Set the correct base in the document?
if ( strpos( $url, './' ) === 0 ) {
$url = 'https://local' . str_replace( '$1', substr( $url, 2 ), $config->get( 'ArticlePath' ) );
} elseif ( strpos( $url, '://' ) === false ) {
$url = 'https://local' . $url;
}
$articlePathRegexp = '/' . str_replace(
preg_quote( '$1', '/' ),
'(.*)',
preg_quote( $config->get( 'ArticlePath' ), '/' )
) . '/';
$matches = null;
if ( preg_match( $articlePathRegexp, $url, $matches ) ) {
return Title::newFromText( urldecode( $matches[1] ) );
}
return null;
}
/**
* Traverse the document in depth-first order, calling the callback whenever entering and leaving
* a node. The walk starts before the given node and ends when callback returns a truthy value, or
* after reaching the end of the document.
*
* You might also think about this as processing XML token stream linearly (rather than XML
* nodes), as if we were parsing the document.
*
* @param DOMNode $node Node to start at
* @param callable $callback Function accepting two arguments: $event ('enter' or 'leave') and
* $node (DOMNode)
* @return mixed Final return value of the callback
*/
public static function linearWalk( DOMNode $node, callable $callback ) {
$result = null;
[ $withinNode, $beforeNode ] = [ $node->parentNode, $node ];
while ( $beforeNode || $withinNode ) {
if ( $beforeNode ) {
$result = $callback( 'enter', $beforeNode );
[ $withinNode, $beforeNode ] = [ $beforeNode, $beforeNode->firstChild ];
} else {
$result = $callback( 'leave', $withinNode );
[ $withinNode, $beforeNode ] = [ $withinNode->parentNode, $withinNode->nextSibling ];
}
if ( $result ) {
return $result;
}
}
return $result;
}
}