mediawiki-extensions-Discus.../includes/ThreadItem.php
Bartosz Dziewoński aea36bab3a CommentParser: Fix a small use of global state
Also, in ThreadItem::getSinglePageTransclusionTitle(), we don't need
this terribly complicated method.

Change-Id: If02c09aaa2f4dd66b2bc253a1edec4ea107564ee
2022-02-21 18:15:31 +00:00

430 lines
12 KiB
PHP

<?php
namespace MediaWiki\Extension\DiscussionTools;
use JsonSerializable;
use LogicException;
use Title;
use Wikimedia\Assert\Assert;
use Wikimedia\Parsoid\DOM\Element;
use Wikimedia\Parsoid\DOM\Node;
use Wikimedia\Parsoid\Utils\DOMUtils;
/**
* A thread item, either a heading or a comment
*/
abstract class ThreadItem implements JsonSerializable {
protected $type;
protected $range;
protected $rootNode;
protected $level;
protected $parent;
protected $warnings = [];
protected $name = null;
protected $id = null;
protected $legacyId = null;
protected $replies = [];
/**
* @param string $type `heading` or `comment`
* @param int $level Indentation level
* @param ImmutableRange $range Object describing the extent of the comment, including the
* signature and timestamp.
*/
public function __construct(
string $type, int $level, ImmutableRange $range
) {
$this->type = $type;
$this->level = $level;
$this->range = $range;
}
/**
* @return array JSON-serializable array
*/
public function jsonSerialize(): array {
// The output of this method can end up in the HTTP cache (Varnish). Avoid changing it;
// and when doing so, ensure that frontend code can handle both the old and new outputs.
// See ThreadItem.static.newFromJSON in JS.
return [
'type' => $this->type,
'level' => $this->level,
'id' => $this->id,
'replies' => array_map( static function ( ThreadItem $comment ) {
return $comment->getId();
}, $this->replies )
];
}
/**
* Get the list of authors in the comment tree below this thread item.
*
* Usually called on a HeadingItem to find all authors in a thread.
*
* @return string[] Author usernames
*/
public function getAuthorsBelow(): array {
$authors = [];
$getAuthorSet = static function ( ThreadItem $comment ) use ( &$authors, &$getAuthorSet ) {
if ( $comment instanceof CommentItem ) {
$authors[ $comment->getAuthor() ] = true;
}
// Get the set of authors in the same format from each reply
foreach ( $comment->getReplies() as $reply ) {
$getAuthorSet( $reply );
}
};
foreach ( $this->getReplies() as $reply ) {
$getAuthorSet( $reply );
}
ksort( $authors );
return array_keys( $authors );
}
/**
* Get the name of the page from which this thread item is transcluded (if any). Replies to
* transcluded items must be posted on that page, instead of the current one.
*
* This is tricky, because we don't want to mark items as trancluded when they're just using a
* template (e.g. {{ping|…}} or a non-substituted signature template). Sometimes the whole comment
* can be template-generated (e.g. when using some wrapper templates), but as long as a reply can
* be added outside of that template, we should not treat it as transcluded.
*
* The start/end boundary points of comment ranges and Parsoid transclusion ranges don't line up
* exactly, even when to a human it's obvious that they cover the same content, making this more
* complicated.
*
* @return string|bool `false` if this item is not transcluded. A string if it's transcluded
* from a single page (the page title, in text form with spaces). `true` if it's transcluded, but
* we can't determine the source.
*/
public function getTranscludedFrom() {
// General approach:
//
// Compare the comment range to each transclusion range on the page, and if it overlaps any of
// them, examine the overlap. There are a few cases:
//
// * Comment and transclusion do not overlap:
// → Not transcluded.
// * Comment contains the transclusion:
// → Not transcluded (just a template).
// * Comment is contained within the transclusion:
// → Transcluded, we can determine the source page (unless it's a complex transclusion).
// * Comment and transclusion overlap partially:
// → Transcluded, but we can't determine the source page.
// * Comment (almost) exactly matches the transclusion:
// → Maybe transcluded (it could be that the source page only contains that single comment),
// maybe not transcluded (it could be a wrapper template that covers a single comment).
// This is very sad, and we decide based on the namespace.
//
// Most transclusion ranges on the page trivially fall in the "do not overlap" or "contains"
// cases, and we only have to carefully examine the two transclusion ranges that contain the
// first and last node of the comment range.
//
// To check for almost exact matches, we walk between the relevant boundary points, and if we
// only find uninteresting nodes (that would be ignored when detecting comments), we treat them
// like exact matches.
$commentRange = $this->getRange();
$startTransclNode = CommentUtils::getTranscludedFromElement(
CommentUtils::getRangeFirstNode( $commentRange )
);
$endTransclNode = CommentUtils::getTranscludedFromElement(
CommentUtils::getRangeLastNode( $commentRange )
);
// We only have to examine the two transclusion ranges that contain the first/last node of the
// comment range (if they exist). Ignore ranges outside the comment or in the middle of it.
$transclNodes = [];
if ( $startTransclNode ) {
$transclNodes[] = $startTransclNode;
}
if ( $endTransclNode && $endTransclNode !== $startTransclNode ) {
$transclNodes[] = $endTransclNode;
}
foreach ( $transclNodes as $transclNode ) {
$transclRange = self::getTransclusionRange( $transclNode );
$compared = CommentUtils::compareRanges( $commentRange, $transclRange );
$transclTitle = $this->getSinglePageTransclusionTitle( $transclNode );
switch ( $compared ) {
case 'equal':
// Comment (almost) exactly matches the transclusion
if ( $transclTitle === null ) {
// Multi-template transclusion, or a parser function call, or template-affected wikitext outside
// of a template call, or a mix of the above
return true;
} elseif ( $transclTitle->inNamespace( NS_TEMPLATE ) ) {
// Is that a subpage transclusion with a single comment, or a wrapper template
// transclusion on this page? We don't know, but let's guess based on the namespace.
// (T289873)
// Continue examining the other ranges.
break;
} else {
return $transclTitle->getPrefixedText();
}
case 'contains':
// Comment contains the transclusion
// If the entire transclusion is contained within the comment range, that's just a
// template. This is the same as a transclusion in the middle of the comment, which we
// ignored earlier, it just takes us longer to get here in this case.
// Continue examining the other ranges.
break;
case 'contained':
// Comment is contained within the transclusion
if ( $transclTitle === null ) {
return true;
} else {
return $transclTitle->getPrefixedText();
}
case 'after':
case 'before':
// Comment and transclusion do not overlap
// This should be impossible, because we ignored these ranges earlier.
throw new LogicException( 'Unexpected transclusion or comment range' );
case 'overlapstart':
case 'overlapend':
// Comment and transclusion overlap partially
return true;
default:
throw new LogicException( 'Unexpected return value from compareRanges()' );
}
}
// If we got here, the comment range was not contained by or overlapping any of the transclusion
// ranges. Comment is not transcluded.
return false;
}
/**
* If the node represents a single-page transclusion, return that page's title.
* Otherwise return null.
*
* @param Element $node
* @return Title|null
*/
private function getSinglePageTransclusionTitle( Element $node ) {
$dataMw = json_decode( $node->getAttribute( 'data-mw' ) ?? '', true );
// Only return a page name if this is a simple single-template transclusion.
if (
is_array( $dataMw ) &&
$dataMw['parts'] &&
count( $dataMw['parts'] ) === 1 &&
$dataMw['parts'][0]['template'] &&
// 'href' will be unset if this is a parser function rather than a template
isset( $dataMw['parts'][0]['template']['target']['href'] )
) {
$parsoidHref = $dataMw['parts'][0]['template']['target']['href'];
Assert::precondition( substr( $parsoidHref, 0, 2 ) === './', "href has valid format" );
return Title::newFromText( urldecode( substr( $parsoidHref, 2 ) ) );
}
return null;
}
/**
* Given a transclusion's first node (e.g. returned by CommentUtils::getTranscludedFromElement()),
* return a range starting before the node and ending after the transclusion's last node.
*
* @param Element $startNode
* @return ImmutableRange
*/
private function getTransclusionRange( Element $startNode ) {
$endNode = $startNode;
while (
// Phan doesn't realize that the conditions on $nextSibling can terminate the loop
// @phan-suppress-next-line PhanInfiniteLoop
$endNode &&
( $nextSibling = $endNode->nextSibling ) &&
$nextSibling instanceof Element &&
$nextSibling->getAttribute( 'about' ) === $endNode->getAttribute( 'about' )
) {
$endNode = $nextSibling;
}
$range = new ImmutableRange(
$startNode->parentNode,
CommentUtils::childIndexOf( $startNode ),
$endNode->parentNode,
CommentUtils::childIndexOf( $endNode ) + 1
);
return $range;
}
/**
* Get the HTML of this thread item
*
* @return string HTML
*/
public function getHTML(): string {
$fragment = $this->getRange()->cloneContents();
CommentModifier::unwrapFragment( $fragment );
return DOMUtils::getFragmentInnerHTML( $fragment );
}
/**
* Get the text of this thread item
*
* @return string Text
*/
public function getText(): string {
$fragment = $this->getRange()->cloneContents();
return $fragment->textContent ?? '';
}
/**
* @return string Thread item type
*/
public function getType(): string {
return $this->type;
}
/**
* @return int Indentation level
*/
public function getLevel(): int {
return $this->level;
}
/**
* @return ThreadItem|null Parent thread item
*/
public function getParent(): ?ThreadItem {
return $this->parent;
}
/**
* @return ImmutableRange Range of the entire thread item
*/
public function getRange(): ImmutableRange {
return $this->range;
}
/**
* @return Node Root node (level is relative to this node)
*/
public function getRootNode(): Node {
return $this->rootNode;
}
/**
* @return string Thread item name
*/
public function getName(): string {
return $this->name;
}
/**
* @return string Thread ID
*/
public function getId(): string {
return $this->id;
}
/**
* @return string|null Thread ID, according to an older algorithm
*/
public function getLegacyId(): ?string {
return $this->legacyId;
}
/**
* @return ThreadItem[] Replies to this thread item
*/
public function getReplies(): array {
return $this->replies;
}
/**
* @return string[] Warnings
*/
public function getWarnings(): array {
return $this->warnings;
}
/**
* @param int $level Indentation level
*/
public function setLevel( int $level ): void {
$this->level = $level;
}
/**
* @param ThreadItem $parent
*/
public function setParent( ThreadItem $parent ): void {
$this->parent = $parent;
}
/**
* @param ImmutableRange $range Thread item range
*/
public function setRange( ImmutableRange $range ): void {
$this->range = $range;
}
/**
* @param Node $rootNode Root node (level is relative to this node)
*/
public function setRootNode( Node $rootNode ): void {
$this->rootNode = $rootNode;
}
/**
* @param string|null $name Thread item name
*/
public function setName( ?string $name ): void {
$this->name = $name;
}
/**
* @param string|null $id Thread ID
*/
public function setId( ?string $id ): void {
$this->id = $id;
}
/**
* @param string|null $id Thread ID
*/
public function setLegacyId( ?string $id ): void {
$this->legacyId = $id;
}
/**
* @param string $warning
*/
public function addWarning( string $warning ): void {
$this->warnings[] = $warning;
}
/**
* @param string[] $warnings
*/
public function addWarnings( array $warnings ): void {
$this->warnings = array_merge( $this->warnings, $warnings );
}
/**
* @param ThreadItem $reply Reply comment
*/
public function addReply( ThreadItem $reply ): void {
$this->replies[] = $reply;
}
}