mediawiki-extensions-Echo/includes/DiscussionParser.php
Reedy 4814d14b85 Update comment about AbuseFilterVariableHolder
Change-Id: I81f71179ce7af081bedf1ed36bdb1aed80f9a08f
2021-10-14 21:38:55 +01:00

1284 lines
39 KiB
PHP

<?php
use MediaWiki\MediaWikiServices;
use MediaWiki\Revision\RevisionRecord;
use MediaWiki\Revision\SlotRecord;
use MediaWiki\User\UserNameUtils;
abstract class EchoDiscussionParser {
private const HEADER_REGEX = '^(==+)\h*([^=].*)\h*\1$';
public const DEFAULT_SNIPPET_LENGTH = 150;
/** @var string|null */
protected static $timestampRegex;
/** @var array[][] */
protected static $revisionInterpretationCache = [];
/** @var EchoDiffParser|null */
protected static $diffParser;
/**
* Given a RevisionRecord object, generates EchoEvent objects for
* the discussion-related actions that occurred in that Revision.
*
* @param RevisionRecord $revision
* @param bool $isRevert
*/
public static function generateEventsForRevision( RevisionRecord $revision, $isRevert ) {
global $wgEchoMentionsOnMultipleSectionEdits;
global $wgEchoMentionOnChanges;
$store = MediaWikiServices::getInstance()->getRevisionStore();
// use replica database if there is a previous revision
if ( $store->getPreviousRevision( $revision ) ) {
$title = Title::newFromID( $revision->getPageId() );
// use primary database for new page
} else {
$title = Title::newFromID( $revision->getPageId(), Title::GAID_FOR_UPDATE );
}
// not a valid title
if ( !$title ) {
return;
}
$events = [];
$interpretation = self::getChangeInterpretationForRevision( $revision );
$userID = $revision->getUser()->getId();
$userName = $revision->getUser()->getName();
$user = $userID !== 0 ? User::newFromId( $userID ) : User::newFromName( $userName, false );
foreach ( $interpretation as $action ) {
if ( $action['type'] === 'add-comment' ) {
$fullSection = $action['full-section'];
$header = self::extractHeader( $fullSection );
$userLinks = self::getUserLinks( $action['content'], $title );
$events = array_merge(
$events,
self::collectMentionEvents( $header, $userLinks, $action['content'], $revision, $user )
);
} elseif ( $action['type'] === 'new-section-with-comment' ) {
$content = $action['content'];
$header = self::extractHeader( $content );
$userLinks = self::getUserLinks( $content, $title );
$events = array_merge(
$events,
self::collectMentionEvents( $header, $userLinks, $content, $revision, $user )
);
} elseif ( $action['type'] === 'add-section-multiple' && $wgEchoMentionsOnMultipleSectionEdits ) {
$content = self::stripHeader( $action['content'] );
$content = self::stripSignature( $content );
$userLinks = self::getUserLinks( $content, $title );
$events = array_merge(
$events,
self::collectMentionEvents( $action['header'], $userLinks, $content, $revision, $user )
);
} elseif ( $action['type'] === 'unknown-signed-change' ) {
$userLinks = array_diff_key(
self::getUserLinks( $action['new_content'], $title ),
self::getUserLinks( $action['old_content'], $title )
);
$header = self::extractHeader( $action['full-section'] );
if ( $wgEchoMentionOnChanges ) {
$events = array_merge(
$events,
self::collectMentionEvents( $header, $userLinks, $action['new_content'], $revision, $user )
);
}
}
}
if ( $title->getNamespace() === NS_USER_TALK ) {
$notifyUser = User::newFromName( $title->getText() );
// If the recipient is a valid non-anonymous user and hasn't turned
// off their notifications, generate a talk page post Echo notification.
if ( $notifyUser && $notifyUser->getId() ) {
$permManager = MediaWikiServices::getInstance()->getPermissionManager();
// If this is a minor edit, only notify if the agent doesn't have talk page minor
// edit notification blocked
if ( !$revision->isMinor() || !$permManager->userHasRight( $user, 'nominornewtalk' ) ) {
$section = self::detectSectionTitleAndText( $interpretation, $title );
if ( $section['section-text'] === '' ) {
$comment = $revision->getComment( RevisionRecord::FOR_PUBLIC, $notifyUser );
if ( $comment ) {
$section['section-text'] = $comment->text;
}
}
$events[] = [
'type' => 'edit-user-talk',
'title' => $title,
'extra' => [
'revid' => $revision->getId(),
'minoredit' => $revision->isMinor(),
'section-title' => $section['section-title'],
'section-text' => $section['section-text'],
'target-page' => $title->getArticleID(),
],
'agent' => $user,
];
}
}
}
// Notify users mentioned in edit summary
global $wgEchoMaxMentionsInEditSummary;
if ( $wgEchoMaxMentionsInEditSummary > 0 && !$user->isBot() && !$isRevert ) {
$summaryParser = new EchoSummaryParser();
$usersInSummary = $summaryParser->parse( $revision->getComment()->text );
// Don't allow pinging yourself
unset( $usersInSummary[$userName] );
$count = 0;
$mentionedUsers = [];
foreach ( $usersInSummary as $summaryUser ) {
if ( $summaryUser->getTalkPage()->equals( $title ) ) {
// Users already get a ping when their talk page is edited
continue;
}
if ( $count >= $wgEchoMaxMentionsInEditSummary ) {
break;
}
$mentionedUsers[$summaryUser->getId()] = $summaryUser->getId();
$count++;
}
if ( $mentionedUsers ) {
$events[] = [
'type' => 'mention-summary',
'title' => $title,
'extra' => [
'revid' => $revision->getId(),
'mentioned-users' => $mentionedUsers,
],
'agent' => $user,
];
}
}
// Allow extensions to generate more events for a revision, and de-duplicate
// against the standard events created above.
Hooks::run( 'EchoGetEventsForRevision', [ &$events, $revision, $isRevert ] );
// Create events
foreach ( $events as $event ) {
EchoEvent::create( $event );
}
}
/**
* Attempts to determine what section title the edit was performed under (if any)
*
* @param array[] $interpretation Results of {@see getChangeInterpretationForRevision}
* @param Title|null $title
* @return string[] Array containing section title and text
*/
public static function detectSectionTitleAndText( array $interpretation, Title $title = null ) {
$header = $snippet = '';
$found = false;
foreach ( $interpretation as $action ) {
switch ( $action['type'] ) {
case 'add-comment':
$header = self::extractHeader( $action['full-section'] );
$snippet = self::getTextSnippet(
self::stripSignature( self::stripHeader( $action['content'] ), $title ),
RequestContext::getMain()->getLanguage(),
self::DEFAULT_SNIPPET_LENGTH,
$title );
break;
case 'new-section-with-comment':
$header = self::extractHeader( $action['content'] );
$snippet = self::getTextSnippet(
self::stripSignature( self::stripHeader( $action['content'] ), $title ),
RequestContext::getMain()->getLanguage(),
self::DEFAULT_SNIPPET_LENGTH,
$title );
break;
}
if ( $header ) {
// If we find a second header within the same change interpretation then
// we cannot choose just 1 to link to
if ( $found ) {
$found = false;
break;
}
$found = true;
}
}
if ( !$found ) {
return [ 'section-title' => '', 'section-text' => '' ];
}
return [ 'section-title' => $header, 'section-text' => $snippet ];
}
/**
* For an action taken on a talk page, notify users whose user pages
* are linked.
* @param string $header The subject line for the discussion.
* @param int[] $userLinks
* @param string $content The content of the post, as a wikitext string.
* @param RevisionRecord $revision
* @param User $agent The user who made the comment.
*/
public static function generateMentionEvents(
$header,
array $userLinks,
$content,
RevisionRecord $revision,
User $agent
) {
$events = self::collectMentionEvents( $header, $userLinks, $content, $revision, $agent );
foreach ( $events as $event ) {
EchoEvent::create( $event );
}
}
/**
* Generate mention event data for a talk page action
* @param string $header The subject line for the discussion.
* @param int[] $userLinks
* @param string $content The content of the post, as a wikitext string.
* @param RevisionRecord $revision
* @param User $agent The user who made the comment.
* @return array List of event info arrays
*/
protected static function collectMentionEvents(
$header,
array $userLinks,
$content,
RevisionRecord $revision,
User $agent
) {
global $wgEchoMaxMentionsCount, $wgEchoMentionStatusNotifications;
$title = Title::newFromLinkTarget( $revision->getPageAsLinkTarget() );
if ( !$title ) {
return [];
}
$content = self::stripHeader( $content );
$content = self::stripSignature( $content, $title );
if ( !$userLinks ) {
return [];
}
$userMentions = self::getUserMentions(
$title, $revision->getUser( RevisionRecord::RAW )->getId(), $userLinks
);
$overallMentionsCount = self::getOverallUserMentionsCount( $userMentions );
if ( $overallMentionsCount === 0 ) {
return [];
}
$events = [];
$stats = MediaWikiServices::getInstance()->getStatsdDataFactory();
if ( $overallMentionsCount > $wgEchoMaxMentionsCount ) {
if ( $wgEchoMentionStatusNotifications ) {
$events[] = [
'type' => 'mention-failure-too-many',
'title' => $title,
'extra' => [
'max-mentions' => $wgEchoMaxMentionsCount,
'section-title' => $header,
],
'agent' => $agent,
];
$stats->increment( 'echo.event.mention.notification.failure-too-many' );
}
return $events;
}
if ( $userMentions['validMentions'] ) {
$events[] = [
'type' => 'mention',
'title' => $title,
'extra' => [
'content' => $content,
'section-title' => $header,
'revid' => $revision->getId(),
'mentioned-users' => $userMentions['validMentions'],
],
'agent' => $agent,
];
}
if ( $wgEchoMentionStatusNotifications ) {
// TODO batch?
foreach ( $userMentions['validMentions'] as $mentionedUserId ) {
$events[] = [
'type' => 'mention-success',
'title' => $title,
'extra' => [
'subject-name' => User::newFromId( $mentionedUserId )->getName(),
'section-title' => $header,
'revid' => $revision->getId(),
],
'agent' => $agent,
];
$stats->increment( 'echo.event.mention.notification.success' );
}
// TODO batch?
foreach ( $userMentions['anonymousUsers'] as $anonymousUser ) {
$events[] = [
'type' => 'mention-failure',
'title' => $title,
'extra' => [
'failure-type' => 'user-anonymous',
'subject-name' => $anonymousUser,
'section-title' => $header,
'revid' => $revision->getId(),
],
'agent' => $agent,
];
$stats->increment( 'echo.event.mention.notification.failure-user-anonymous' );
}
// TODO batch?
foreach ( $userMentions['unknownUsers'] as $unknownUser ) {
$events[] = [
'type' => 'mention-failure',
'title' => $title,
'extra' => [
'failure-type' => 'user-unknown',
'subject-name' => $unknownUser,
'section-title' => $header,
'revid' => $revision->getId(),
],
'agent' => $agent,
];
$stats->increment( 'echo.event.mention.notification.failure-user-unknown' );
}
}
return $events;
}
private static function getOverallUserMentionsCount( array $userMentions ) {
return count( $userMentions, COUNT_RECURSIVE ) - count( $userMentions );
}
/**
* @param Title $title
* @param int $revisionUserId
* @param int[] $userLinks
* @return array[]
* Set of arrays containing valid mentions and possible intended but failed mentions.
* - [validMentions]: An array of valid users to mention with ID => ID.
* - [unknownUsers]: An array of DBKey strings representing unknown users.
* - [anonymousUsers]: An array of DBKey strings representing anonymous IP users.
*/
private static function getUserMentions( Title $title, $revisionUserId, array $userLinks ) {
global $wgEchoMaxMentionsCount;
$userMentions = [
'validMentions' => [],
'unknownUsers' => [],
'anonymousUsers' => [],
];
$count = 0;
$stats = MediaWikiServices::getInstance()->getStatsdDataFactory();
$userNameUtils = MediaWikiServices::getInstance()->getUserNameUtils();
foreach ( $userLinks as $dbk => $page_id ) {
// If more users are being pinged this is likely a spam/attack vector
// Don't send any mention notifications.
if ( $count > $wgEchoMaxMentionsCount ) {
$stats->increment( 'echo.event.mention.error.tooMany' );
break;
}
// we should not add user to 'mention' notification list if
// 1. the user link links to a subpage
if ( self::hasSubpage( $dbk ) ) {
continue;
}
// 2. user is an anonymous IP
if ( $userNameUtils->isIP( $dbk ) ) {
$userMentions['anonymousUsers'][] = $dbk;
$count++;
$stats->increment( 'echo.event.mention.error.anonUser' );
continue;
}
$user = User::newFromName( $dbk );
// 3. the user name is not valid
if ( !$user ) {
$userMentions['unknownUsers'][] = str_replace( '_', ' ', $dbk );
$count++;
$stats->increment( 'echo.event.mention.error.invalidUser' );
continue;
}
// 4. the user mentions themselves
if ( $user->getId() === $revisionUserId ) {
$stats->increment( 'echo.event.mention.error.sameUser' );
continue;
}
// 5. the user is the owner of the talk page
if ( $title->getNamespace() === NS_USER_TALK && $title->getDBkey() === $dbk ) {
$stats->increment( 'echo.event.mention.error.ownPage' );
continue;
}
// 6. user does not exist
if ( $user->getId() === 0 ) {
$userMentions['unknownUsers'][] = str_replace( '_', ' ', $dbk );
$count++;
$stats->increment( 'echo.event.mention.error.unknownUser' );
continue;
}
$userMentions['validMentions'][$user->getId()] = $user->getId();
$count++;
}
return $userMentions;
}
/**
* @param string $content
* @param Title $title
* @return int[]
* Array of links in the user namespace with DBKey => ID.
*/
private static function getUserLinks( $content, Title $title ) {
$output = self::parseNonEditWikitext( $content, new Article( $title ) );
$links = $output->getLinks();
if ( !isset( $links[NS_USER] ) || !is_array( $links[NS_USER] ) ) {
return [];
}
return $links[NS_USER];
}
private static function hasSubpage( $dbk ) {
return strpos( $dbk, '/' ) !== false;
}
/**
* It's like Article::prepareTextForEdit,
* but not for editing (old wikitext usually)
* Stolen from AbuseFilter's VariableHolder
*
* @param string $wikitext
* @param Article $article
*
* @return ParserOutput
*/
private static function parseNonEditWikitext( $wikitext, Article $article ) {
static $cache = [];
$cacheKey = md5( $wikitext ) . ':' . $article->getTitle()->getPrefixedText();
if ( isset( $cache[$cacheKey] ) ) {
return $cache[$cacheKey];
}
$parser = MediaWikiServices::getInstance()->getParser();
$options = new ParserOptions( $article->getContext()->getUser() );
$output = $parser->parse( $wikitext, $article->getTitle(), $options );
$cache[$cacheKey] = $output;
return $output;
}
/**
* Given a Revision object, returns a talk-page-centric interpretation
* of the changes made in it.
*
* @param RevisionRecord $revision
* @see EchoDiscussionParser::interpretDiff
* @return array[] See {@see interpretDiff} for details.
*/
private static function getChangeInterpretationForRevision( RevisionRecord $revision ) {
if ( $revision->getId() && isset( self::$revisionInterpretationCache[$revision->getId()] ) ) {
return self::$revisionInterpretationCache[$revision->getId()];
}
$userIdentity = $revision->getUser();
$userID = $userIdentity ? $userIdentity->getId() : 0;
$userName = $userIdentity ? $userIdentity->getName() : '';
$user = $userID !== 0 ? User::newFromId( $userID ) : User::newFromName( $userName, false );
$prevText = '';
if ( $revision->getParentId() ) {
$store = MediaWikiServices::getInstance()->getRevisionStore();
$prevRevision = $store->getRevisionById( $revision->getParentId() );
if ( $prevRevision ) {
$prevContent = $prevRevision->getContent( SlotRecord::MAIN );
$prevText = ( $prevContent instanceof TextContent ) ? $prevContent->getText() : '';
}
}
$content = $revision->getContent( SlotRecord::MAIN );
$changes = self::getMachineReadableDiff(
$prevText,
( $content instanceof TextContent ) ? $content->getText() : null
);
$output = self::interpretDiff(
$changes,
$user->getName(),
Title::newFromLinkTarget( $revision->getPageAsLinkTarget() )
);
self::$revisionInterpretationCache[$revision->getId()] = $output;
return $output;
}
/**
* Given a machine-readable diff, interprets the changes
* in terms of discussion page actions
*
* @todo Expand recognisable actions.
*
* @param array[] $changes Output of EchoEvent::getMachineReadableDiff
* @param string $username
* @param Title|null $title
* @return array[] Array of associative arrays.
*
* Each entry represents an action, which is classified in the 'action' field.
* All types contain a 'content' field except 'unknown'
* (which instead passes through the machine-readable diff in 'details')
* and 'unknown-change' (which provides 'new_content' and 'old_content')
* action may be:
* - add-comment: A comment signed by the user is added to an
* existing section.
* - new-section-with-comment: A new section is added, containing
* a single comment signed by the user in question.
* - add-section-multiple: A new section or additions to a section
* while editing multiple sections at once.
* - unknown-multi-signed-addition: Some signed content is added,
* but it contains multiple signatures.
* - unknown-unsigned-addition: Some content is added, but it is
* unsigned.
* - unknown-subtraction: Some content was removed. These actions are
* not currently analysed.
* - unknown-change: Some content was replaced with other content.
* - unknown-signed-change: Same as unknown-change, but signed.
* - unknown-multi-signed-change: Same as unknown-change,
* but it contains multiple signatures.
* - unknown: Unrecognised change type.
*/
public static function interpretDiff( array $changes, $username, Title $title = null ) {
// One extra item in $changes for _info
$actions = [];
$signedSections = [];
foreach ( $changes as $index => $change ) {
if ( !is_numeric( $index ) ) {
continue;
}
if ( !$change['action'] ) {
// Unknown action; skip
continue;
}
if ( $change['action'] === 'add' ) {
$content = trim( $change['content'] );
// The \A means the regex must match at the beginning of the string.
// This is slightly different than ^ which matches beginning of each
// line in multiline mode.
$startSection = preg_match( '/\A' . self::HEADER_REGEX . '/um', $content );
$sectionCount = self::getSectionCount( $content );
$signedUsers = array_keys( self::extractSignatures( $content, $title ) );
if (
count( $signedUsers ) === 1 &&
in_array( $username, $signedUsers )
) {
if ( $sectionCount === 0 ) {
$signedSections[] = self::getSectionSpan( $change['right-pos'], $changes['_info']['rhs'] );
$fullSection = self::getFullSection( $changes['_info']['rhs'], $change['right-pos'] );
$actions[] = [
'type' => 'add-comment',
'content' => $content,
'full-section' => $fullSection,
];
} elseif ( $startSection && $sectionCount === 1 ) {
$signedSections[] = self::getSectionSpan( $change['right-pos'], $changes['_info']['rhs'] );
$actions[] = [
'type' => 'new-section-with-comment',
'content' => $content,
];
} else {
$nextSectionStart = $change['right-pos'];
$sectionData = self::extractSections( $content );
foreach ( $sectionData as $section ) {
$sectionSpan = self::getSectionSpan( $nextSectionStart, $changes['_info']['rhs'] );
$nextSectionStart = $sectionSpan[1] + 1;
$sectionSignedUsers = self::extractSignatures( $section['content'], $title );
if ( !empty( $sectionSignedUsers ) ) {
$signedSections[] = $sectionSpan;
if ( !$section['header'] ) {
$fullSection = self::getFullSection(
$changes['_info']['rhs'],
$change['right-pos']
);
$section['header'] = self::extractHeader( $fullSection );
}
$actions[] = [
'type' => 'add-section-multiple',
'content' => $section['content'],
'header' => $section['header'],
];
} else {
$actions[] = [
'type' => 'unknown-unsigned-addition',
'content' => $section['content'],
];
}
}
}
} elseif ( $signedUsers !== [] ) {
$actions[] = [
'type' => 'unknown-multi-signed-addition',
'content' => $content,
];
} else {
$actions[] = [
'type' => 'unknown-unsigned-addition',
'content' => $content,
];
}
} elseif ( $change['action'] === 'subtract' ) {
$actions[] = [
'type' => 'unknown-subtraction',
'content' => $change['content'],
];
} elseif ( $change['action'] === 'change' ) {
$actions[] = [
'type' => 'unknown-change',
'old_content' => $change['old_content'],
'new_content' => $change['new_content'],
'right-pos' => $change['right-pos'],
'full-section' => self::getFullSection( $changes['_info']['rhs'], $change['right-pos'] ),
];
if ( self::hasNewSignature(
$change['old_content'],
$change['new_content'],
$username,
$title
) ) {
$signedSections[] = self::getSectionSpan( $change['right-pos'], $changes['_info']['rhs'] );
}
} else {
$actions[] = [
'type' => 'unknown',
'details' => $change,
];
}
}
if ( !empty( $signedSections ) ) {
$actions = self::convertToUnknownSignedChanges( $signedSections, $actions );
}
return $actions;
}
private static function getSignedUsers( $content, $title ) {
return array_keys( self::extractSignatures( $content, $title ) );
}
private static function hasNewSignature( $oldContent, $newContent, $username, $title ) {
$oldSignedUsers = self::getSignedUsers( $oldContent, $title );
$newSignedUsers = self::getSignedUsers( $newContent, $title );
return !in_array( $username, $oldSignedUsers ) && in_array( $username, $newSignedUsers );
}
/**
* Converts actions of type "unknown-change" to "unknown-signed-change" if the change is in a signed section.
*
* @param array[] $signedSections Array of arrays containing first and last line number of signed sections
* @param array[] $actions
* @return array[] Converted actions
*/
private static function convertToUnknownSignedChanges( array $signedSections, array $actions ) {
return array_map( function ( $action ) use( $signedSections ) {
if (
$action['type'] === 'unknown-change' &&
self::isInSignedSection( $action['right-pos'], $signedSections )
) {
$signedUsers = self::getSignedUsers( $action['new_content'], null );
if ( count( $signedUsers ) === 1 ) {
$action['type'] = 'unknown-signed-change';
} else {
$action['type'] = 'unknown-multi-signed-change';
}
}
return $action;
}, $actions );
}
/**
* @param int $line
* @param array[] $signedSections
* @return bool
*/
private static function isInSignedSection( $line, array $signedSections ) {
foreach ( $signedSections as $section ) {
if ( $line > $section[0] && $line <= $section[1] ) {
return true;
}
}
return false;
}
/**
* Finds the section that a given line is in.
*
* @param array $lines of lines in the page.
* @param int $offset The line to find the full section for.
* @return string Content of the section.
*/
public static function getFullSection( array $lines, $offset ) {
$start = self::getSectionStartIndex( $offset, $lines );
$end = self::getSectionEndIndex( $offset, $lines );
$content = implode( "\n", array_slice( $lines, $start, $end - $start ) );
return trim( $content, "\n" );
}
/**
* Given a line number and a text, find the first and last line of the section the line number is in.
* If there are subsections, the last line index will be the line before the beginning of the first subsection.
* @param int $offset line number
* @param string[] $lines
* @return int[] Tuple [$firstLine, $lastLine]
*/
private static function getSectionSpan( $offset, array $lines ) {
return [
self::getSectionStartIndex( $offset, $lines ),
self::getSectionEndIndex( $offset, $lines )
];
}
/**
* Finds the line number of the start of the section that $offset is in.
* @param int $offset
* @param string[] $lines
* @return int
*/
private static function getSectionStartIndex( $offset, array $lines ) {
for ( $i = $offset - 1; $i >= 0; $i-- ) {
if ( self::getSectionCount( $lines[$i] ) ) {
break;
}
}
return $i;
}
/**
* Finds the line number of the end of the section that $offset is in.
* @param int $offset
* @param array $lines
* @return int
*/
private static function getSectionEndIndex( $offset, array $lines ) {
$lastLine = count( $lines );
for ( $i = $offset; $i < $lastLine; $i++ ) {
if ( self::getSectionCount( $lines[$i] ) ) {
break;
}
}
return $i;
}
/**
* Gets the number of section headers in a string.
*
* @param string $text
* @return int Number of section headers found.
*/
public static function getSectionCount( $text ) {
$text = trim( $text );
return (int)preg_match_all( '/' . self::HEADER_REGEX . '/um', $text );
}
/**
* Gets the title of a section or sub section
*
* @param string $text The text of the section.
* @return string|false The title of the section or false if not found
*/
public static function extractHeader( $text ) {
$text = trim( $text );
$matches = [];
if ( !preg_match_all( '/' . self::HEADER_REGEX . '/um', $text, $matches ) ) {
return false;
}
return trim( end( $matches[2] ) );
}
/**
* Extracts sections and their contents from text.
*
* @param string $text The text to parse.
* @return array[]
* Array of arrays containing sections with header and content.
* - [header]: The full header string of the section or false if there is preceding text without header.
* - [content]: The content of the section including the header string.
*/
private static function extractSections( $text ) {
$matches = [];
if ( !preg_match_all( '/' . self::HEADER_REGEX . '/um', $text, $matches, PREG_OFFSET_CAPTURE ) ) {
return [ [
'header' => false,
'content' => $text
] ];
}
$sectionNum = count( $matches[0] );
$sections = [];
if ( $matches[0][0][1] > 1 ) { // is there text before the first headline?
$sections[] = [
'header' => false,
'content' => substr( $text, 0, $matches[0][0][1] - 1 )
];
}
for ( $i = 0; $i < $sectionNum; $i++ ) {
if ( $i + 1 < $sectionNum ) {
$content = substr( $text, $matches[0][$i][1], $matches[0][$i + 1][1] - $matches[0][$i][1] );
} else {
$content = substr( $text, $matches[0][$i][1] );
}
$sections[] = [
'header' => self::extractHeader( $matches[0][$i][0] ),
'content' => trim( $content )
];
}
return $sections;
}
/**
* Strips out a signature if possible.
*
* @param string $text The wikitext to strip
* @param Title|null $title
* @return string
*/
private static function stripSignature( $text, Title $title = null ) {
$output = self::getUserFromLine( $text, $title );
if ( $output === false ) {
$timestampPos = self::getTimestampPosition( $text );
return substr( $text, 0, $timestampPos );
}
// Use truncateForDatabase() instead of truncateHTML() because
// truncateHTML() would not strip signature if the text contains
// < or &. (And we can't use truncateForVisual() because
// self::getUserFromLine() returns byte offsets, not character
// offsets.)
return MediaWikiServices::getInstance()->getContentLanguage()
->truncateForDatabase( $text, $output[0], '' );
}
/**
* Strips out a section header
* @param string $text The text to strip out the section header from.
* @return string The same text, with the section header stripped out.
*/
private static function stripHeader( $text ) {
$text = preg_replace( '/' . self::HEADER_REGEX . '/um', '', $text );
return $text;
}
/**
* Determines whether the input is a signed comment.
*
* @param string $text The text to check.
* @param User|bool $user If set, will only return true if the comment is
* signed by this user.
* @param Title|null $title
* @return bool
*/
public static function isSignedComment( $text, $user = false, Title $title = null ) {
$userData = self::getUserFromLine( $text, $title );
if ( $userData === false ) {
return false;
} elseif ( $user === false ) {
return true;
}
list( , $foundUser ) = $userData;
$userNameUtils = MediaWikiServices::getInstance()->getUserNameUtils();
return $userNameUtils->getCanonical( $foundUser, UserNameUtils::RIGOR_NONE ) ===
$userNameUtils->getCanonical( $user, UserNameUtils::RIGOR_NONE );
}
/**
* Finds the start position, if any, of the timestamp on a line
*
* @param string $line The line to search for a signature on
* @return int|false Integer position
*/
public static function getTimestampPosition( $line ) {
$timestampRegex = self::getTimestampRegex();
$tsMatches = [];
if ( !preg_match(
"/$timestampRegex/mu",
$line,
$tsMatches,
PREG_OFFSET_CAPTURE
) ) {
return false;
}
return $tsMatches[0][1];
}
/**
* Finds differences between $oldText and $newText
* and returns the result in a machine-readable format.
*
* @param string $oldText The "left hand side" of the diff.
* @param string $newText The "right hand side" of the diff.
* @throws MWException
* @return array[] Array of changes.
* Each change consists of:
* * An 'action', one of:
* - add
* - subtract
* - change
* * 'content' that was added or removed, or in the case
* of a change, 'old_content' and 'new_content'
* * 'left_pos' and 'right_pos' (in lines) of the change.
*/
public static function getMachineReadableDiff( $oldText, $newText ) {
if ( !isset( self::$diffParser ) ) {
self::$diffParser = new EchoDiffParser;
}
return self::$diffParser->getChangeSet( $oldText, $newText );
}
/**
* Finds and extracts signatures in $text
*
* @param string $text The text in which to look for signed comments.
* @param Title|null $title
* @return string[] Associative array, the key is the username, the value
* is the last signature that was found.
*/
private static function extractSignatures( $text, Title $title = null ) {
$lines = explode( "\n", $text );
$output = [];
$lineNumber = 0;
foreach ( $lines as $line ) {
++$lineNumber;
// Look for the last user link on the line.
$userData = self::getUserFromLine( $line, $title );
if ( $userData === false ) {
continue;
}
list( $signaturePos, $user ) = $userData;
$signature = substr( $line, $signaturePos );
$output[$user] = $signature;
}
return $output;
}
/**
* From a line in the signature, extract all the users linked to
*
* @param string $line Line of text potentially including linked user, user talk,
* and contribution pages
* @return string[] array of usernames, empty array for none detected
*/
public static function extractUsersFromLine( $line ) {
/*
* Signatures can look like anything (as defined by i18n messages
* "signature" & "signature-anon").
* A signature can, e.g., be both a link to user & user-talk page.
*/
// match all title-like excerpts in this line
if ( !preg_match_all( '/\[\[([^\[]+)\]\]/', $line, $matches ) ) {
return [];
}
$matches = $matches[1];
$usernames = [];
foreach ( $matches as $match ) {
/*
* Create an object out of the link title.
* In theory, links can be [[text]], [[text|text]] or pipe tricks
* [[text|]] or [[|text]].
* In the case of reverse pipe trick, the value we use *could* be
* empty, but Parser::pstPass2 should have normalized that for us
* already.
*/
$match = explode( '|', $match, 2 );
$title = Title::newFromText( $match[0] );
// figure out if we the link is related to a user
if (
$title &&
( $title->getNamespace() === NS_USER || $title->getNamespace() === NS_USER_TALK )
) {
$usernames[] = $title->getText();
} elseif ( $title && $title->isSpecial( 'Contributions' ) ) {
$parts = explode( '/', $title->getText(), 2 );
$usernames[] = end( $parts );
} else {
// move on to next matched title-like excerpt
continue;
}
}
return $usernames;
}
/**
* From a line in a wiki page, determine which user, if any,
* has signed it.
*
* @param string $line
* @param Title|null $title
* @return array|false False for none, array for success.
* - First element is the position of the signature.
* - Second element is the normalised user name.
*/
public static function getUserFromLine( $line, Title $title = null ) {
$parser = MediaWikiServices::getInstance()->getParser();
/*
* First we call extractUsersFromLine to get all the potential usernames
* from the line. Then, we loop backwards through them, figure out which
* match to a user, regenera the signature based on that user, and
* see if it matches!
*/
$usernames = self::extractUsersFromLine( $line );
$usernames = array_reverse( $usernames );
foreach ( $usernames as $username ) {
// generate (dateless) signature from the user we think we've
// discovered the signature from
// don't validate the username - anon (IP) is fine!
$user = User::newFromName( $username, false );
$sig = $parser->preSaveTransform(
'~~~',
$title ?: Title::newMainPage(),
$user,
new ParserOptions( $user )
);
// see if we can find this user's generated signature in the content
$pos = strrpos( $line, $sig );
if ( $pos !== false ) {
return [ $pos, $username ];
}
// couldn't find sig, move on to next link excerpt and try there
}
// couldn't find any matching signature
return false;
}
/**
* Find the last link beginning with a given prefix on a line.
*
* @param string $line The line to search.
* @param string $linkPrefix The prefix to search for.
* @param int|false $failureOffset
* @return array|false False for failure, array for success.
* - First element is the string offset of the link.
* - Second element is the user the link refers to.
*/
private static function getLinkFromLine( $line, $linkPrefix, $failureOffset = false ) {
$offset = 0;
// If extraction failed at another offset, try again.
if ( $failureOffset !== false ) {
$offset = $failureOffset - strlen( $line ) - 1;
}
// Avoid PHP warning: Offset is greater than the length of haystack string
if ( abs( $offset ) > strlen( $line ) ) {
return false;
}
$linkPos = strripos( $line, $linkPrefix, $offset );
if ( $linkPos === false ) {
return false;
}
$linkUser = self::extractUserFromLink( $line, $linkPrefix, $linkPos );
if ( $linkUser === false ) {
// Look for another place.
return self::getLinkFromLine( $line, $linkPrefix, $linkPos );
} else {
return [ $linkPos, $linkUser ];
}
}
/**
* Given text including a link, gives the user that that link refers to
*
* @param string $text The text to extract from.
* @param string $prefix The link prefix that was used to find the link.
* @param int $offset Optionally, the offset of the start of the link.
* @return bool|string Type description
*/
private static function extractUserFromLink( $text, $prefix, $offset = 0 ) {
$userPart = substr( $text, strlen( $prefix ) + $offset );
$userMatches = [];
if ( !preg_match(
'/^[^\|\]\#]+/u',
$userPart,
$userMatches
) ) {
// user link is invalid
return false;
}
$user = $userMatches[0];
$userNameUtils = MediaWikiServices::getInstance()->getUserNameUtils();
if (
!$userNameUtils->isIP( $user ) &&
$userNameUtils->getCanonical( $user ) === false
) {
// Not a real username
return false;
}
return $userNameUtils->getCanonical( $userMatches[0], UserNameUtils::RIGOR_NONE );
}
/**
* Gets a regular expression that will match this wiki's
* timestamps as given by ~~~~.
*
* @throws MWException
* @return string regular expression fragment.
*/
public static function getTimestampRegex() {
if ( self::$timestampRegex !== null ) {
return self::$timestampRegex;
}
// Step 1: Get an exemplar timestamp
$title = Title::newMainPage();
$user = User::newFromName( 'Test' );
$options = new ParserOptions( $user );
$parser = MediaWikiServices::getInstance()->getParser();
$exemplarTimestamp =
$parser->preSaveTransform( '~~~~~', $title, $user, $options );
// Step 2: Generalise it
// Trim off the timezone to replace at the end
$output = $exemplarTimestamp;
$tzRegex = '/\h*\(\w+\)\h*$/u';
$tzMatches = [];
if ( preg_match( $tzRegex, $output, $tzMatches, PREG_OFFSET_CAPTURE ) ) {
$output = substr( $output, 0, $tzMatches[0][1] );
}
$output = preg_quote( $output, '/' );
$output = preg_replace( '/[^\d\W]+/u', '[^\d\W]+', $output );
$output = preg_replace( '/\d+/u', '\d+', $output );
if ( $tzMatches ) {
$output .= preg_quote( $tzMatches[0][0] );
}
if ( !preg_match( "/$output/u", $exemplarTimestamp ) ) {
throw new MWException( "Timestamp regex does not match exemplar" );
}
self::$timestampRegex = $output;
return $output;
}
/**
* Parse wikitext into truncated plain text.
* @param string $text
* @param Language $lang
* @param int $length Length in characters (not bytes); default DEFAULT_SNIPPET_LENGTH
* @param Title|null $title Page from which the text snippet is being extracted
* @return string
*/
public static function getTextSnippet(
$text, Language $lang, $length = self::DEFAULT_SNIPPET_LENGTH, $title = null
) {
// Parse wikitext
$html = MediaWikiServices::getInstance()->getMessageCache()->parse( $text, $title )->getText( [
'enableSectionEditLinks' => false
] );
$plaintext = trim( Sanitizer::stripAllTags( $html ) );
return $lang->truncateForVisual( $plaintext, $length );
}
/**
* Parse an edit summary into truncated plain text.
* @param string $text
* @param Language $lang
* @param int $length Length in characters (not bytes); default DEFAULT_SNIPPET_LENGTH
* @return string
*/
public static function getTextSnippetFromSummary( $text, Language $lang, $length = self::DEFAULT_SNIPPET_LENGTH ) {
// Parse wikitext with summary parser
$html = Linker::formatLinksInComment( Sanitizer::escapeHtmlAllowEntities( $text ) );
$plaintext = trim( Sanitizer::stripAllTags( $html ) );
return $lang->truncateForVisual( $plaintext, $length );
}
/**
* Extract an edit excerpt from a revision
*
* @param RevisionRecord $revision
* @param Language $lang
* @param int $length Length in characters (not bytes); default DEFAULT_SNIPPET_LENGTH
* @return string
*/
public static function getEditExcerpt(
RevisionRecord $revision, Language $lang, $length = self::DEFAULT_SNIPPET_LENGTH
) {
$interpretation = self::getChangeInterpretationForRevision( $revision );
$section = self::detectSectionTitleAndText( $interpretation );
return $lang->truncateForVisual( $section['section-title'] . ' ' . $section['section-text'], $length );
}
}