mediawiki-extensions-Discus.../includes/CommentParser.php
Bartosz Dziewoński cfa45a5f4c Remove all stuff about legacy IDs
We can no longer change IDs so easily, because they're stored in the
permalink database, so remove this mechanism to make sure it's not
accidentally used in the future.

Change-Id: I392ee1f49c48fc2f23d05e9a37c643438b4f2b9a
2022-08-24 01:01:09 +02:00

1120 lines
37 KiB
PHP

<?php
namespace MediaWiki\Extension\DiscussionTools;
use Config;
use DateInterval;
use DateTime;
use DateTimeImmutable;
use DateTimeZone;
use Language;
use MalformedTitleException;
use MediaWiki\Extension\DiscussionTools\ThreadItem\CommentItem;
use MediaWiki\Extension\DiscussionTools\ThreadItem\ContentCommentItem;
use MediaWiki\Extension\DiscussionTools\ThreadItem\ContentHeadingItem;
use MediaWiki\Extension\DiscussionTools\ThreadItem\ContentThreadItem;
use MediaWiki\Extension\DiscussionTools\ThreadItem\ThreadItem;
use MediaWiki\Languages\LanguageConverterFactory;
use MWException;
use TitleParser;
use TitleValue;
use Wikimedia\Assert\Assert;
use Wikimedia\IPUtils;
use Wikimedia\Parsoid\DOM\Element;
use Wikimedia\Parsoid\DOM\Node;
use Wikimedia\Parsoid\DOM\Text;
use Wikimedia\Parsoid\Utils\DOMCompat;
// TODO consider making timestamp parsing not a returned function
class CommentParser {
/**
* How far backwards we look for a signature associated with a timestamp before giving up.
* Note that this is not a hard limit on the length of signatures we detect.
*/
private const SIGNATURE_SCAN_LIMIT = 100;
/** @var Config */
private $config;
/** @var Language */
private $language;
/** @var LanguageConverterFactory */
private $languageConverterFactory;
/** @var TitleParser */
private $titleParser;
private $dateFormat;
private $digits;
/** @var string[][] */
private $contLangMessages;
private $localTimezone;
private $timezones;
private $specialContributionsName;
/** @var Element */
private $rootNode;
/** @var TitleValue */
private $title;
/**
* @param Config $config
* @param Language $language Content language
* @param LanguageConverterFactory $languageConverterFactory
* @param LanguageData $languageData
* @param TitleParser $titleParser
*/
public function __construct(
Config $config,
Language $language,
LanguageConverterFactory $languageConverterFactory,
LanguageData $languageData,
TitleParser $titleParser
) {
$this->config = $config;
$this->language = $language;
$this->languageConverterFactory = $languageConverterFactory;
$this->titleParser = $titleParser;
$data = $languageData->getLocalData();
$this->dateFormat = $data['dateFormat'];
$this->digits = $data['digits'];
$this->contLangMessages = $data['contLangMessages'];
$this->localTimezone = $data['localTimezone'];
$this->timezones = $data['timezones'];
$this->specialContributionsName = $data['specialContributionsName'];
}
/**
* Parse a discussion page.
*
* @param Element $rootNode Root node of content to parse
* @param TitleValue $title Title of the page being parsed
* @return ContentThreadItemSet
*/
public function parse( Element $rootNode, TitleValue $title ): ContentThreadItemSet {
$this->rootNode = $rootNode;
$this->title = $title;
$result = $this->buildThreadItems();
$this->buildThreads( $result );
$this->computeIdsAndNames( $result );
return $result;
}
/**
* Return the next leaf node in the tree order that is likely a part of a discussion comment,
* rather than some boring "separator" element.
*
* Currently, this can return a Text node with content other than whitespace, or an Element node
* that is a "void element" or "text element", except some special cases that we treat as comment
* separators (isCommentSeparator()).
*
* @param Node $node Node to start searching at. This node's children are ignored.
* @return Node
*/
private function nextInterestingLeafNode( Node $node ): Node {
$rootNode = $this->rootNode;
$treeWalker = new TreeWalker(
$rootNode,
NodeFilter::SHOW_ELEMENT | NodeFilter::SHOW_TEXT,
static function ( $n ) use ( $node, $rootNode ) {
// Ignore this node and its descendants
// (unless it's the root node, this is a special case for "fakeHeading" handling)
if ( $node !== $rootNode && ( $n === $node || $n->parentNode === $node ) ) {
return NodeFilter::FILTER_REJECT;
}
// Ignore some elements usually used as separators or headers (and their descendants)
if ( CommentUtils::isCommentSeparator( $n ) ) {
return NodeFilter::FILTER_REJECT;
}
// Ignore nodes with no rendering that mess up our indentation detection
if ( CommentUtils::isRenderingTransparentNode( $n ) ) {
return NodeFilter::FILTER_REJECT;
}
if ( CommentUtils::isCommentContent( $n ) ) {
return NodeFilter::FILTER_ACCEPT;
}
return NodeFilter::FILTER_SKIP;
}
);
$treeWalker->currentNode = $node;
$treeWalker->nextNode();
if ( !$treeWalker->currentNode ) {
throw new MWException( 'nextInterestingLeafNode not found' );
}
return $treeWalker->currentNode;
}
/**
* @param string[] $values Values to match
* @return string Regular expression
*/
private static function regexpAlternateGroup( array $values ): string {
return '(' . implode( '|', array_map( static function ( string $x ) {
return preg_quote( $x, '/' );
}, $values ) ) . ')';
}
/**
* Get text of localisation messages in content language.
*
* @param string $contLangVariant Content language variant
* @param string[] $messages Message keys
* @return string[] Message values
*/
private function getMessages( string $contLangVariant, array $messages ): array {
return array_map( function ( string $key ) use ( $contLangVariant ) {
return $this->contLangMessages[$contLangVariant][$key];
}, $messages );
}
/**
* Get a regexp that matches timestamps generated using the given date format.
*
* This only supports format characters that are used by the default date format in any of
* MediaWiki's languages, namely: D, d, F, G, H, i, j, l, M, n, Y, xg, xkY (and escape characters),
* and only dates when MediaWiki existed, let's say 2000 onwards (Thai dates before 1941 are
* complicated).
*
* @param string $contLangVariant Content language variant
* @param string $format Date format
* @param string $digitsRegexp Regular expression matching a single localised digit, e.g. '[0-9]'
* @param array $tzAbbrs Associative array mapping localised timezone abbreviations to
* IANA abbreviations, for the local timezone, e.g. [ 'EDT' => 'EDT', 'EST' => 'EST' ]
* @return string Regular expression
*/
private function getTimestampRegexp(
string $contLangVariant, string $format, string $digitsRegexp, array $tzAbbrs
): string {
$formatLength = strlen( $format );
$s = '';
// Adapted from Language::sprintfDate()
for ( $p = 0; $p < $formatLength; $p++ ) {
$num = false;
$code = $format[ $p ];
if ( $code === 'x' && $p < $formatLength - 1 ) {
$code .= $format[++$p];
}
if ( $code === 'xk' && $p < $formatLength - 1 ) {
$code .= $format[++$p];
}
switch ( $code ) {
case 'xx':
$s .= 'x';
break;
case 'xg':
$s .= static::regexpAlternateGroup(
$this->getMessages( $contLangVariant, Language::MONTH_GENITIVE_MESSAGES )
);
break;
case 'd':
$num = '2';
break;
case 'D':
$s .= static::regexpAlternateGroup(
$this->getMessages( $contLangVariant, Language::WEEKDAY_ABBREVIATED_MESSAGES )
);
break;
case 'j':
$num = '1,2';
break;
case 'l':
$s .= static::regexpAlternateGroup(
$this->getMessages( $contLangVariant, Language::WEEKDAY_MESSAGES )
);
break;
case 'F':
$s .= static::regexpAlternateGroup(
$this->getMessages( $contLangVariant, Language::MONTH_MESSAGES )
);
break;
case 'M':
$s .= static::regexpAlternateGroup(
$this->getMessages( $contLangVariant, Language::MONTH_ABBREVIATED_MESSAGES )
);
break;
case 'n':
$num = '1,2';
break;
case 'Y':
$num = '4';
break;
case 'xkY':
$num = '4';
break;
case 'G':
$num = '1,2';
break;
case 'H':
$num = '2';
break;
case 'i':
$num = '2';
break;
case '\\':
// Backslash escaping
if ( $p < $formatLength - 1 ) {
$s .= preg_quote( $format[++$p], '/' );
} else {
$s .= preg_quote( '\\', '/' );
}
break;
case '"':
// Quoted literal
if ( $p < $formatLength - 1 ) {
$endQuote = strpos( $format, '"', $p + 1 );
if ( $endQuote === false ) {
// No terminating quote, assume literal "
$s .= '"';
} else {
$s .= preg_quote( substr( $format, $p + 1, $endQuote - $p - 1 ), '/' );
$p = $endQuote;
}
} else {
// Quote at end of string, assume literal "
$s .= '"';
}
break;
default:
// Copy whole characters together, instead of single bytes
$char = mb_substr( mb_strcut( $format, $p, 4 ), 0, 1 );
$s .= preg_quote( $char, '/' );
$p += strlen( $char ) - 1;
}
if ( $num !== false ) {
$s .= '(' . $digitsRegexp . '{' . $num . '})';
}
// Ignore some invisible Unicode characters that often sneak into copy-pasted timestamps (T308448)
$s .= '[\\x{200E}\\x{200F}]?';
}
$tzRegexp = static::regexpAlternateGroup( array_keys( $tzAbbrs ) );
// Hard-coded parentheses and space like in Parser::pstPass2
// Ignore some invisible Unicode characters that often sneak into copy-pasted timestamps (T245784)
// \uNNNN syntax can only be used from PHP 7.3
return '/' . $s . ' [\\x{200E}\\x{200F}]?\\(' . $tzRegexp . '\\)/u';
}
/**
* Get a function that parses timestamps generated using the given date format, based on the result
* of matching the regexp returned by getTimestampRegexp()
*
* @param string $contLangVariant Content language variant
* @param string $format Date format, as used by MediaWiki
* @param string[]|null $digits Localised digits from 0 to 9, e.g. `[ '0', '1', ..., '9' ]`
* @param string $localTimezone Local timezone IANA name, e.g. `America/New_York`
* @param array $tzAbbrs Map of localised timezone abbreviations to IANA abbreviations
* for the local timezone, e.g. [ 'EDT' => 'EDT', 'EST' => 'EST' ]
* @return callable Parser function
*/
private function getTimestampParser(
string $contLangVariant, string $format, ?array $digits, string $localTimezone, array $tzAbbrs
): callable {
$untransformDigits = static function ( string $text ) use ( $digits ) {
if ( !$digits ) {
return $text;
}
return preg_replace_callback(
'/[' . implode( '', $digits ) . ']/u',
static function ( array $m ) use ( $digits ) {
return (string)array_search( $m[0], $digits );
},
$text
);
};
$formatLength = strlen( $format );
$matchingGroups = [];
for ( $p = 0; $p < $formatLength; $p++ ) {
$code = $format[$p];
if ( $code === 'x' && $p < $formatLength - 1 ) {
$code .= $format[++$p];
}
if ( $code === 'xk' && $p < $formatLength - 1 ) {
$code .= $format[++$p];
}
switch ( $code ) {
case 'xx':
break;
case 'xg':
case 'd':
case 'j':
case 'D':
case 'l':
case 'F':
case 'M':
case 'n':
case 'Y':
case 'xkY':
case 'G':
case 'H':
case 'i':
$matchingGroups[] = $code;
break;
case '\\':
// Backslash escaping
if ( $p < $formatLength - 1 ) {
$p++;
}
break;
case '"':
// Quoted literal
if ( $p < $formatLength - 1 ) {
$endQuote = strpos( $format, '"', $p + 1 );
if ( $endQuote !== false ) {
$p = $endQuote;
}
}
break;
default:
break;
}
}
return function ( array $match ) use (
$matchingGroups, $untransformDigits, $localTimezone, $tzAbbrs, $contLangVariant
) {
if ( is_array( $match[0] ) ) {
// Strip PREG_OFFSET_CAPTURE data
unset( $match['offset'] );
$match = array_map( static function ( array $tuple ) {
return $tuple[0];
}, $match );
}
$year = 0;
$monthIdx = 0;
$day = 0;
$hour = 0;
$minute = 0;
foreach ( $matchingGroups as $i => $code ) {
$text = $match[$i + 1];
switch ( $code ) {
case 'xg':
$monthIdx = array_search(
$text,
$this->getMessages( $contLangVariant, Language::MONTH_GENITIVE_MESSAGES )
);
break;
case 'd':
case 'j':
$day = intval( $untransformDigits( $text ) );
break;
case 'D':
case 'l':
// Day of the week - unused
break;
case 'F':
$monthIdx = array_search(
$text,
$this->getMessages( $contLangVariant, Language::MONTH_MESSAGES )
);
break;
case 'M':
$monthIdx = array_search(
$text,
$this->getMessages( $contLangVariant, Language::MONTH_ABBREVIATED_MESSAGES )
);
break;
case 'n':
$monthIdx = intval( $untransformDigits( $text ) ) - 1;
break;
case 'Y':
$year = intval( $untransformDigits( $text ) );
break;
case 'xkY':
// Thai year
$year = intval( $untransformDigits( $text ) ) - 543;
break;
case 'G':
case 'H':
$hour = intval( $untransformDigits( $text ) );
break;
case 'i':
$minute = intval( $untransformDigits( $text ) );
break;
default:
// TODO throw NotImplementedException or whatever it's called
throw new MWException( 'Not implemented' );
}
}
// The last matching group is the timezone abbreviation
$tzAbbr = $tzAbbrs[ end( $match ) ];
// Most of the time, the timezone abbreviation is not necessary to parse the date, since we
// can assume all times are in the wiki's local timezone.
$date = new DateTime();
// setTimezone must be called before setDate/setTime
$date->setTimezone( new DateTimeZone( $localTimezone ) );
$date->setDate( $year, $monthIdx + 1, $day );
$date->setTime( $hour, $minute, 0 );
// But during the "fall back" at the end of DST, some times will happen twice.
// Since the timezone abbreviation disambiguates the DST/non-DST times, we can detect
// when PHP chose the wrong one, and then try the other one. It appears that PHP always
// uses the later (non-DST) hour, but that behavior isn't documented, so we account for both.
$dateWarning = null;
if ( $date->format( 'T' ) !== $tzAbbr ) {
$altDate = clone $date;
if ( $date->format( 'I' ) ) {
// Parsed time is DST, try non-DST by advancing one hour
$altDate->add( new DateInterval( 'PT1H' ) );
} else {
// Parsed time is non-DST, try DST by going back one hour
$altDate->sub( new DateInterval( 'PT1H' ) );
}
if ( $altDate->format( 'T' ) === $tzAbbr ) {
$date = $altDate;
$dateWarning = 'Timestamp has timezone abbreviation for the wrong time';
} else {
$dateWarning = 'Ambiguous time at DST switchover was parsed';
}
}
// Now set the timezone back to UTC for formatting
$date->setTimezone( new DateTimeZone( 'UTC' ) );
$date = DateTimeImmutable::createFromMutable( $date );
return [
'date' => $date,
'warning' => $dateWarning,
];
};
}
/**
* Get a regexp that matches timestamps in the local date format, for each language variant.
*
* This calls getTimestampRegexp() with predefined data for the current wiki.
*
* @return string[] Regular expressions
*/
public function getLocalTimestampRegexps(): array {
$langConv = $this->languageConverterFactory->getLanguageConverter( $this->language );
return array_map( function ( $contLangVariant ) {
return $this->getTimestampRegexp(
$contLangVariant,
$this->dateFormat[$contLangVariant],
'[' . implode( '', $this->digits[$contLangVariant] ) . ']',
$this->timezones[$contLangVariant]
);
}, $langConv->getVariants() );
}
/**
* Get a function that parses timestamps in the local date format, for each language variant,
* based on the result of matching the regexp returned by getLocalTimestampRegexp().
*
* This calls getTimestampParser() with predefined data for the current wiki.
*
* @return callable[] Parser functions
*/
private function getLocalTimestampParsers(): array {
$langConv = $this->languageConverterFactory->getLanguageConverter( $this->language );
return array_map( function ( $contLangVariant ) {
return $this->getTimestampParser(
$contLangVariant,
$this->dateFormat[$contLangVariant],
$this->digits[$contLangVariant],
$this->localTimezone,
$this->timezones[$contLangVariant]
);
}, $langConv->getVariants() );
}
/**
* Given a link node (`<a>`), if it's a link to a user-related page, return their username.
*
* @param Element $link
* @return string|null Username, or null
*/
private function getUsernameFromLink( Element $link ): ?string {
// Selflink: use title of current page
if ( DOMCompat::getClassList( $link )->contains( 'mw-selflink' ) ) {
$title = $this->title;
} else {
$titleString = CommentUtils::getTitleFromUrl( $link->getAttribute( 'href' ) ?? '', $this->config ) ?? '';
try {
$title = $this->titleParser->parseTitle( $titleString );
} catch ( MalformedTitleException $err ) {
return null;
}
}
$username = null;
$namespaceId = $title->getNamespace();
$mainText = $title->getText();
if ( $namespaceId === NS_USER || $namespaceId === NS_USER_TALK ) {
$username = $mainText;
if ( strpos( $username, '/' ) !== false ) {
return null;
}
} elseif ( $namespaceId === NS_SPECIAL ) {
$parts = explode( '/', $mainText );
if ( count( $parts ) === 2 && $parts[0] === $this->specialContributionsName ) {
// Normalize the username: users may link to their contributions with an unnormalized name
$userpage = $this->titleParser->makeTitleValueSafe( NS_USER, $parts[1] );
if ( !$userpage ) {
return null;
}
$username = $userpage->getText();
}
}
if ( !$username ) {
return null;
}
if ( IPUtils::isIPv6( $username ) ) {
// Bot-generated links "Preceding unsigned comment added by" have non-standard case
$username = strtoupper( $username );
}
return $username;
}
/**
* Find a user signature preceding a timestamp.
*
* The signature includes the timestamp node.
*
* A signature must contain at least one link to the user's userpage, discussion page or
* contributions (and may contain other links). The link may be nested in other elements.
*
* @param Text $timestampNode
* @param Node|null $until Node to stop searching at
* @return array Result, an associative array with the following keys:
* - Node[] `nodes` Sibling nodes comprising the signature, in reverse order (with
* $timestampNode or its parent node as the first element)
* - string|null `username` Username, null for unsigned comments
*/
private function findSignature( Text $timestampNode, ?Node $until = null ): array {
$sigUsername = null;
$length = 0;
$lastLinkNode = $timestampNode;
CommentUtils::linearWalkBackwards(
$timestampNode,
function ( string $event, Node $node ) use (
&$sigUsername, &$lastLinkNode, &$length,
$until, $timestampNode
) {
if ( $event === 'enter' && $node === $until ) {
return true;
}
if ( $length >= static::SIGNATURE_SCAN_LIMIT ) {
return true;
}
if ( CommentUtils::isBlockElement( $node ) ) {
// Don't allow reaching into preceding paragraphs
return true;
}
if ( $event === 'leave' && $node !== $timestampNode ) {
$length += $node instanceof Text ?
mb_strlen( CommentUtils::htmlTrim( $node->textContent ?? '' ) ) : 0;
}
// Find the closest link before timestamp that links to the user's user page.
//
// Support timestamps being linked to the diff introducing the comment:
// if the timestamp node is the only child of a link node, use the link node instead
//
// Handle links nested in formatting elements.
if ( $event === 'leave' && $node instanceof Element && strtolower( $node->tagName ) === 'a' ) {
$username = $this->getUsernameFromLink( $node );
if ( $username ) {
// Accept the first link to the user namespace, then only accept links to that user
if ( $sigUsername === null ) {
$sigUsername = $username;
}
if ( $username === $sigUsername ) {
$lastLinkNode = $node;
}
}
// Keep looking if a node with links wasn't a link to a user page
// "Doc James (talk · contribs · email)"
}
}
);
$range = new ImmutableRange(
$lastLinkNode->parentNode,
CommentUtils::childIndexOf( $lastLinkNode ),
$timestampNode->parentNode,
CommentUtils::childIndexOf( $timestampNode ) + 1
);
// Expand the range so that it covers sibling nodes.
// This will include any wrapping formatting elements as part of the signature.
//
// Helpful accidental feature: users whose signature is not detected in full (due to
// text formatting) can just wrap it in a <span> to fix that.
// "Ten Pound Hammer • (What did I screw up now?)"
// "« Saper // dyskusja »"
//
// TODO Not sure if this is actually good, might be better to just use the range...
$sigNodes = array_reverse( CommentUtils::getCoveredSiblings( $range ) );
return [
'nodes' => $sigNodes,
'username' => $sigUsername
];
}
/**
* Callback for TreeWalker that will skip over nodes where we don't want to detect
* comments (or section headings).
*
* @param Node $node
* @return int Appropriate NodeFilter constant
*/
public static function acceptOnlyNodesAllowingComments( Node $node ): int {
if ( $node instanceof Element ) {
$tagName = strtolower( $node->tagName );
// The table of contents has a heading that gets erroneously detected as a section
if ( $node->getAttribute( 'id' ) === 'toc' ) {
return NodeFilter::FILTER_REJECT;
}
// Don't detect comments within references. We can't add replies to them without bungling up
// the structure in some cases (T301213), and you're not supposed to do that anyway…
if (
// <ol class="references"> is the only reliably consistent thing between the two parsers
$tagName === 'ol' &&
DOMCompat::getClassList( $node )->contains( 'references' )
) {
return NodeFilter::FILTER_REJECT;
}
// Don't detect comments within quotes (T275881)
if (
$tagName === 'blockquote' ||
$tagName === 'cite' ||
$tagName === 'q'
) {
return NodeFilter::FILTER_REJECT;
}
}
$parentNode = $node->parentNode;
// Don't detect comments within headings (but don't reject the headings themselves)
if ( $parentNode instanceof Element && preg_match( '/^h([1-6])$/i', $parentNode->tagName ) ) {
return NodeFilter::FILTER_REJECT;
}
return NodeFilter::FILTER_ACCEPT;
}
/**
* Find a timestamps in a given text node
*
* @param Text $node
* @param string[] $timestampRegexps
* @return array|null Array with the following keys:
* - int 'offset' Length of extra text preceding the node that was used for matching (in bytes)
* - int 'parserIndex' Which of the regexps matched
* - array 'matchData' Regexp match data, which specifies the location of the match,
* and which can be parsed using getLocalTimestampParsers() (offsets are in bytes)
*/
public function findTimestamp( Text $node, array $timestampRegexps ): ?array {
$nodeText = '';
$offset = 0;
while ( $node ) {
$nodeText = $node->nodeValue . $nodeText;
// In Parsoid HTML, entities are represented as a 'mw:Entity' node, rather than normal HTML
// entities. On Arabic Wikipedia, the "UTC" timezone name contains some non-breaking spaces,
// which apparently are often turned into &nbsp; entities by buggy editing tools. To handle
// this, we must piece together the text, so that our regexp can match those timestamps.
if (
( $previousSibling = $node->previousSibling ) &&
$previousSibling instanceof Element &&
$previousSibling->getAttribute( 'typeof' ) === 'mw:Entity'
) {
$nodeText = $previousSibling->firstChild->nodeValue . $nodeText;
$offset += strlen( $previousSibling->firstChild->nodeValue ?? '' );
// If the entity is preceded by more text, do this again
if (
$previousSibling->previousSibling &&
$previousSibling->previousSibling instanceof Text
) {
$offset += strlen( $previousSibling->previousSibling->nodeValue ?? '' );
$node = $previousSibling->previousSibling;
} else {
$node = null;
}
} else {
$node = null;
}
}
foreach ( $timestampRegexps as $i => $timestampRegexp ) {
$matchData = null;
// Allows us to mimic match.index in #getComments
if ( preg_match( $timestampRegexp, $nodeText, $matchData, PREG_OFFSET_CAPTURE ) ) {
return [
'matchData' => $matchData,
'offset' => $offset,
'parserIndex' => $i,
];
}
}
return null;
}
/**
* @param Node[] $sigNodes
* @param array $match
* @param Text $node
* @return ImmutableRange
*/
private function adjustSigRange( array $sigNodes, array $match, Text $node ): ImmutableRange {
$firstSigNode = end( $sigNodes );
$lastSigNode = $sigNodes[0];
// TODO Document why this needs to be so complicated
$lastSigNodeOffsetByteOffset =
$match['matchData'][0][1] + strlen( $match['matchData'][0][0] ) - $match['offset'];
$lastSigNodeOffset = $lastSigNode === $node ?
mb_strlen( substr( $node->nodeValue ?? '', 0, $lastSigNodeOffsetByteOffset ) ) :
CommentUtils::childIndexOf( $lastSigNode ) + 1;
$sigRange = new ImmutableRange(
$firstSigNode->parentNode,
CommentUtils::childIndexOf( $firstSigNode ),
$lastSigNode === $node ? $node : $lastSigNode->parentNode,
$lastSigNodeOffset
);
return $sigRange;
}
private function buildThreadItems(): ContentThreadItemSet {
$result = new ContentThreadItemSet();
$timestampRegexps = $this->getLocalTimestampRegexps();
$dfParsers = $this->getLocalTimestampParsers();
$curCommentEnd = $this->rootNode;
$treeWalker = new TreeWalker(
$this->rootNode,
NodeFilter::SHOW_ELEMENT | NodeFilter::SHOW_TEXT,
[ static::class, 'acceptOnlyNodesAllowingComments' ]
);
$lastSigNode = null;
while ( $node = $treeWalker->nextNode() ) {
if ( $node instanceof Element && preg_match( '/^h([1-6])$/i', $node->tagName, $match ) ) {
$headingNodeAndOffset = CommentUtils::getHeadlineNodeAndOffset( $node );
$headingNode = $headingNodeAndOffset['node'];
$startOffset = $headingNodeAndOffset['offset'];
$range = new ImmutableRange(
$headingNode, $startOffset, $headingNode, $headingNode->childNodes->length
);
$curComment = new ContentHeadingItem( $range, (int)( $match[ 1 ] ) );
$curComment->setRootNode( $this->rootNode );
$result->addThreadItem( $curComment );
$curCommentEnd = $node;
} elseif ( $node instanceof Text && ( $match = $this->findTimestamp( $node, $timestampRegexps ) ) ) {
$warnings = [];
$foundSignature = $this->findSignature( $node, $lastSigNode );
$author = $foundSignature['username'];
$lastSigNode = $foundSignature['nodes'][0];
if ( !$author ) {
// Ignore timestamps for which we couldn't find a signature. It's probably not a real
// comment, but just a false match due to a copypasted timestamp.
continue;
}
$sigRanges = [];
$sigRanges[] = $this->adjustSigRange( $foundSignature['nodes'], $match, $node );
// Everything from the last comment up to here is the next comment
$startNode = $this->nextInterestingLeafNode( $curCommentEnd );
$endNode = $lastSigNode;
// Skip to the end of the "paragraph". This only looks at tag names and can be fooled by CSS, but
// avoiding that would be more difficult and slower.
//
// If this skips over another potential signature, also skip it in the main TreeWalker loop, to
// avoid generating multiple comments when there is more than one signature on a single "line".
// Often this is done when someone edits their comment later and wants to add a note about that.
// (Or when another person corrects a typo, or strikes out a comment, etc.) Multiple comments
// within one paragraph/list-item result in a confusing double "Reply" button, and we also have
// no way to indicate which one you're replying to (this might matter in the future for
// notifications or something).
CommentUtils::linearWalk(
$lastSigNode,
function ( string $event, Node $n ) use (
&$endNode, &$sigRanges,
$treeWalker, $timestampRegexps, $node
) {
if ( CommentUtils::isBlockElement( $n ) ) {
// Stop when entering or leaving a block node
return true;
}
if (
$event === 'leave' &&
$n instanceof Text && $n !== $node &&
( $match2 = $this->findTimestamp( $n, $timestampRegexps ) )
) {
// If this skips over another potential signature, also skip it in the main TreeWalker loop
$treeWalker->currentNode = $n;
// …and add it as another signature to this comment (regardless of the author and timestamp)
$foundSignature2 = $this->findSignature( $n, $node );
if ( $foundSignature2['username'] ) {
$sigRanges[] = $this->adjustSigRange( $foundSignature2['nodes'], $match2, $n );
}
}
if ( $event === 'leave' ) {
// Take the last complete node which we skipped past
$endNode = $n;
}
}
);
$length = ( $endNode instanceof Text ) ?
mb_strlen( rtrim( $endNode->nodeValue ?? '', "\t\n\f\r " ) ) :
// PHP bug: childNodes can be null for comment nodes
// (it should always be a NodeList, even if the node can't have children)
( $endNode->childNodes ? $endNode->childNodes->length : 0 );
$range = new ImmutableRange(
$startNode->parentNode,
CommentUtils::childIndexOf( $startNode ),
$endNode,
$length
);
$startLevel = CommentUtils::getIndentLevel( $startNode, $this->rootNode ) + 1;
$endLevel = CommentUtils::getIndentLevel( $node, $this->rootNode ) + 1;
if ( $startLevel !== $endLevel ) {
$warnings[] = 'Comment starts and ends with different indentation';
}
// Should this use the indent level of $startNode or $node?
$level = min( $startLevel, $endLevel );
[ 'date' => $dateTime, 'warning' => $dateWarning ] =
$dfParsers[ $match['parserIndex'] ]( $match['matchData'] );
if ( $dateWarning ) {
$warnings[] = $dateWarning;
}
$curComment = new ContentCommentItem(
$level,
$range,
$sigRanges,
$dateTime,
$author
);
$curComment->setRootNode( $this->rootNode );
if ( $warnings ) {
$curComment->addWarnings( $warnings );
}
if ( $result->isEmpty() ) {
// Add a fake placeholder heading if there are any comments in the 0th section
// (before the first real heading)
$range = new ImmutableRange( $this->rootNode, 0, $this->rootNode, 0 );
$fakeHeading = new ContentHeadingItem( $range, null );
$fakeHeading->setRootNode( $this->rootNode );
$result->addThreadItem( $fakeHeading );
}
$result->addThreadItem( $curComment );
$curCommentEnd = $curComment->getRange()->endContainer;
}
}
return $result;
}
/**
* Truncate user generated parts of IDs so full ID always fits within a database field of length 255
*
* @param string $text Text
* @return string Truncated text
*/
private function truncateForId( string $text ): string {
return $this->language->truncateForDatabase( $text, 80, '' );
}
/**
* Given a thread item, return an identifier for it that is unique within the page.
*
* @param ContentThreadItem $threadItem
* @param ContentThreadItemSet $previousItems
* @return string
*/
private function computeId( ContentThreadItem $threadItem, ContentThreadItemSet $previousItems ): string {
$id = null;
if ( $threadItem instanceof ContentHeadingItem && $threadItem->isPlaceholderHeading() ) {
// The range points to the root note, using it like below results in silly values
$id = 'h-';
} elseif ( $threadItem instanceof ContentHeadingItem ) {
// <span class="mw-headline" …>, or <hN …> in Parsoid HTML
$headline = $threadItem->getRange()->startContainer;
Assert::precondition( $headline instanceof Element, 'HeadingItem refers to an element node' );
$id = 'h-' . $this->truncateForId( $headline->getAttribute( 'id' ) ?? '' );
} elseif ( $threadItem instanceof ContentCommentItem ) {
$id = 'c-' . $this->truncateForId( str_replace( ' ', '_', $threadItem->getAuthor() ) ) .
'-' . $threadItem->getTimestampString();
} else {
throw new MWException( 'Unknown ThreadItem type' );
}
// If there would be multiple comments with the same ID (i.e. the user left multiple comments
// in one edit, or within a minute), add the parent ID to disambiguate them.
$threadItemParent = $threadItem->getParent();
if ( $threadItemParent instanceof ContentHeadingItem && !$threadItemParent->isPlaceholderHeading() ) {
// <span class="mw-headline" …>, or <hN …> in Parsoid HTML
$headline = $threadItemParent->getRange()->startContainer;
Assert::precondition( $headline instanceof Element, 'HeadingItem refers to an element node' );
$id .= '-' . $this->truncateForId( $headline->getAttribute( 'id' ) ?? '' );
} elseif ( $threadItemParent instanceof ContentCommentItem ) {
$id .= '-' . $this->truncateForId( str_replace( ' ', '_', $threadItemParent->getAuthor() ) ) .
'-' . $threadItemParent->getTimestampString();
}
if ( $threadItem instanceof ContentHeadingItem ) {
// To avoid old threads re-appearing on popular pages when someone uses a vague title
// (e.g. dozens of threads titled "question" on [[Wikipedia:Help desk]]: https://w.wiki/fbN),
// include the oldest timestamp in the thread (i.e. date the thread was started) in the
// heading ID.
$oldestComment = $this->getThreadStartComment( $threadItem );
if ( $oldestComment ) {
$id .= '-' . $oldestComment->getTimestampString();
}
}
if ( $previousItems->findCommentById( $id ) ) {
// Well, that's tough
$threadItem->addWarning( 'Duplicate comment ID' );
// Finally, disambiguate by adding sequential numbers, to allow replying to both comments
$number = 1;
while ( $previousItems->findCommentById( "$id-$number" ) ) {
$number++;
}
$id = "$id-$number";
}
return $id;
}
/**
* Given a thread item, return an identifier for it that is consistent across all pages and
* revisions where this comment might appear.
*
* Multiple comments on a page can have the same name; use ID to distinguish them.
*
* @param ContentThreadItem $threadItem
* @return string
*/
private function computeName( ContentThreadItem $threadItem ): string {
$name = null;
if ( $threadItem instanceof ContentHeadingItem ) {
$name = 'h-';
$mainComment = $this->getThreadStartComment( $threadItem );
} elseif ( $threadItem instanceof ContentCommentItem ) {
$name = 'c-';
$mainComment = $threadItem;
} else {
throw new MWException( 'Unknown ThreadItem type' );
}
if ( $mainComment ) {
$name .= $this->truncateForId( str_replace( ' ', '_', $mainComment->getAuthor() ) ) .
'-' . $mainComment->getTimestampString();
}
return $name;
}
/**
* @param ContentThreadItemSet $result
*/
private function buildThreads( ContentThreadItemSet $result ): void {
$lastHeading = null;
$replies = [];
foreach ( $result->getThreadItems() as $threadItem ) {
if ( count( $replies ) < $threadItem->getLevel() ) {
// Someone skipped an indentation level (or several). Pretend that the previous reply
// covers multiple indentation levels, so that following comments get connected to it.
$threadItem->addWarning( 'Comment skips indentation level' );
while ( count( $replies ) < $threadItem->getLevel() ) {
$replies[] = end( $replies );
}
}
if ( $threadItem instanceof ContentHeadingItem ) {
// New root (thread)
// Attach as a sub-thread to preceding higher-level heading.
// Any replies will appear in the tree twice, under the main-thread and the sub-thread.
$maybeParent = $lastHeading;
while ( $maybeParent && $maybeParent->getHeadingLevel() >= $threadItem->getHeadingLevel() ) {
$maybeParent = $maybeParent->getParent();
}
if ( $maybeParent ) {
$threadItem->setParent( $maybeParent );
$maybeParent->addReply( $threadItem );
}
$lastHeading = $threadItem;
} elseif ( isset( $replies[ $threadItem->getLevel() - 1 ] ) ) {
// Add as a reply to the closest less-nested comment
$threadItem->setParent( $replies[ $threadItem->getLevel() - 1 ] );
$threadItem->getParent()->addReply( $threadItem );
} else {
$threadItem->addWarning( 'Comment could not be connected to a thread' );
}
$replies[ $threadItem->getLevel() ] = $threadItem;
// Cut off more deeply nested replies
array_splice( $replies, $threadItem->getLevel() + 1 );
}
}
/**
* Set the IDs and names used to refer to comments and headings.
* This has to be a separate pass because we don't have the list of replies before
* this point.
*
* @param ContentThreadItemSet $result
*/
private function computeIdsAndNames( ContentThreadItemSet $result ): void {
foreach ( $result->getThreadItems() as $threadItem ) {
$name = $this->computeName( $threadItem );
$threadItem->setName( $name );
$id = $this->computeId( $threadItem, $result );
$threadItem->setId( $id );
$result->updateIdAndNameMaps( $threadItem );
}
}
/**
* @param ThreadItem $threadItem
* @return CommentItem|null
*/
private function getThreadStartComment( ThreadItem $threadItem ): ?CommentItem {
$oldest = null;
if ( $threadItem instanceof ContentCommentItem ) {
$oldest = $threadItem;
}
// Check all replies. This can't just use the first comment because threads are often summarized
// at the top when the discussion is closed.
foreach ( $threadItem->getReplies() as $comment ) {
// Don't include sub-threads to avoid changing the ID when threads are "merged".
if ( $comment instanceof ContentCommentItem ) {
$oldestInReplies = $this->getThreadStartComment( $comment );
if ( !$oldest || $oldestInReplies->getTimestamp() < $oldest->getTimestamp() ) {
$oldest = $oldestInReplies;
}
}
}
return $oldest;
}
}