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

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<?php
namespace MediaWiki\Extension\DiscussionTools;
use DOMDocument;
use DOMElement;
use DOMNode;
use stdClass;
class CommentModifier {
private function __construct() {
}
/**
* Add an attribute to a list item to remove pre-whitespace in Parsoid
*
* @param DOMElement $listItem List item element
*/
private static function whitespaceParsoidHack( DOMElement $listItem ) : void {
// HACK: Setting data-parsoid removes the whitespace after the list item,
// which makes nested lists work.
// This is undocumented behaviour and probably very fragile.
$listItem->setAttribute( 'data-parsoid', '{}' );
}
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 Node
* @return bool Node is a block element
*/
private static function isBlockElement( DOMNode $node ) : bool {
return $node->nodeType === XML_ELEMENT_NODE &&
in_array( strtolower( $node->tagName ), self::$blockElementTypes );
}
/**
* Given a comment and a reply link, add the reply link to its document's DOM tree, at the end of
* the comment.
*
* @param stdClass $comment Comment data returned by parser#groupThreads
* @param DOMElement $linkNode Reply link
*/
public static function addReplyLink( stdClass $comment, DOMElement $linkNode ) : void {
$target = $comment->range->endContainer;
// 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.
while ( $target->nextSibling && !self::isBlockElement( $target->nextSibling ) ) {
$target = $target->nextSibling;
}
// Insert the link before trailing whitespace.
// In the MediaWiki parser output, <ul>/<dl> nodes are preceded by a newline. Normally it isn't
// visible on the page. But if we insert an inline element (the reply link) after it, it becomes
// meaningful and gets rendered, which results in additional spacing before some reply links.
// Split the text node, so that we can insert the link before the trailing whitespace.
if ( $target->nodeType === XML_TEXT_NODE ) {
preg_match( '/\s*$/', $target->nodeValue, $matches, PREG_OFFSET_CAPTURE );
$byteOffset = $matches[0][1];
$charOffset = mb_strlen(
substr( $target->nodeValue, 0, $byteOffset )
);
$target->splitText( $charOffset );
}
$target->parentNode->insertBefore( $linkNode, $target->nextSibling );
}
/**
* Given a comment, add a list item to its document's DOM tree, inside of which a reply to said
* comment can be added.
*
* The DOM tree is suitably rearranged to ensure correct indentation level of the reply (wrapper
* nodes are added, and other nodes may be moved around).
*
* @param stdClass $comment Comment data returned by parser#groupThreads
* @return DOMElement
*/
public static function addListItem( stdClass $comment ) : DOMElement {
$listTypeMap = [
'li' => 'ul',
'dd' => 'dl'
];
// 1. Start at given comment
// 2. Skip past all comments with level greater than the given
// (or in other words, all replies, and replies to replies, and so on)
// 3. Add comment with level of the given comment plus 1
$curComment = $comment;
while ( count( $curComment->replies ) ) {
$curComment = end( $curComment->replies );
}
$desiredLevel = $comment->level + 1;
$curLevel = $curComment->level;
$target = $curComment->range->endContainer;
// 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.
while ( $target->nextSibling && !self::isBlockElement( $target->nextSibling ) ) {
$target = $target->nextSibling;
}
// target is a text node or an inline element at the end of a "paragraph"
// (not necessarily paragraph node).
// First, we need to find a block-level parent that we can mess with.
// If we can't find a surrounding list item or paragraph (e.g. maybe we're inside a table cell
// or something), take the parent node and hope for the best.
$parent = CommentUtils::closestElement( $target, [ 'li', 'dd', 'p' ] ) ??
$target->parentNode;
while ( $target->parentNode !== $parent ) {
$target = $target->parentNode;
}
// parent is a list item or paragraph (hopefully)
// target is an inline node within it
if ( $curLevel < $desiredLevel ) {
// Insert more lists after the target to increase nesting.
// If we can't insert a list directly inside this element, insert after it.
// TODO Improve this check
if ( strtolower( $parent->tagName ) === 'p' || strtolower( $parent->tagName ) === 'pre' ) {
$parent = $parent->parentNode;
$target = $target->parentNode;
}
// Decide on tag names for lists and items
$itemType = strtolower( $parent->tagName );
$itemType = isset( $listTypeMap[ $itemType ] ) ? $itemType : 'dd';
$listType = $listTypeMap[ $itemType ];
// Insert required number of wrappers
while ( $curLevel < $desiredLevel ) {
$list = $target->ownerDocument->createElement( $listType );
// Setting modified would only be needed for removeAddedListItem,
// which isn't needed on the server
// $list->setAttribute( 'dt-modified', 'new' );
$item = $target->ownerDocument->createElement( $itemType );
// $item->setAttribute( 'dt-modified', 'new' );
self::whitespaceParsoidHack( $item );
$parent->insertBefore( $list, $target->nextSibling );
$list->appendChild( $item );
$target = $item;
$parent = $list;
$curLevel++;
}
} elseif ( $curLevel >= $desiredLevel ) {
// Split the ancestor nodes after the target to decrease nesting.
do {
// If target is the last child of its parent, no need to split it
if ( $target->nextSibling ) {
// Create new identical node after the parent
$newNode = $parent->cloneNode( false );
// $parent->setAttribute( 'dt-modified', 'split' );
$parent->parentNode->insertBefore( $newNode, $parent->nextSibling );
// Move nodes following target to the new node
while ( $target->nextSibling ) {
$newNode->appendChild( $target->nextSibling );
}
}
$target = $parent;
$parent = $parent->parentNode;
// Decrease nesting level if we escaped outside of a list
if ( isset( $listTypeMap[ strtolower( $target->tagName ) ] ) ) {
$curLevel--;
}
} while ( $curLevel >= $desiredLevel );
// parent is now a list, target is a list item
$item = $target->ownerDocument->createElement( $target->tagName );
// $item->setAttribute( 'dt-modified', 'new' );
self::whitespaceParsoidHack( $item );
$parent->insertBefore( $item, $target->nextSibling );
}
return $item;
}
// removeAddedListItem is only needed in the client
/**
* Unwrap a top level list, converting list item text to paragraphs
*
* Assumes that the list is the only child of it's parent.
*
* @param DOMElement $list List element (dl/ol/ul)
*/
public static function unwrapList( DOMElement $list ) : void {
$doc = $list->ownerDocument;
$container = $list->parentNode;
$container->removeChild( $list );
while ( $list->firstChild ) {
if ( $list->firstChild->nodeType === XML_ELEMENT_NODE ) {
// Move <dd> contents to <p>
$p = $doc->createElement( 'p' );
while ( $list->firstChild->firstChild ) {
// If contents is a block element, place outside the paragraph
// and start a new paragraph after
if ( self::isBlockElement( $list->firstChild->firstChild ) ) {
if ( $p->firstChild ) {
$container->appendChild( $p );
}
$container->appendChild( $list->firstChild->firstChild );
$p = $doc->createElement( 'p' );
} else {
$p->appendChild( $list->firstChild->firstChild );
}
}
if ( $p->firstChild ) {
$container->appendChild( $p );
}
$list->removeChild( $list->firstChild );
} else {
// Text node / comment node, probably empty
$container->appendChild( $list->firstChild );
}
}
}
/**
* Add another list item after the given one.
*
* @param DOMElement $previousItem
* @return DOMElement
*/
public static function addSiblingListItem( DOMElement $previousItem ) : DOMElement {
$listItem = $previousItem->ownerDocument->createElement( $previousItem->tagName->toLowerCase() );
self::whitespaceParsoidHack( $listItem );
$previousItem->parentNode->insertBefore( $listItem, $previousItem->nextSibling );
return $listItem;
}
/**
* Create an element that will convert to the provided wikitext
*
* @param DOMDocument $doc Document
* @param string $wt Wikitext
* @return DOMElement Element
*/
public static function createWikitextNode( DOMDocument $doc, string $wt ) : DOMElement {
$span = $doc->createElement( 'span' );
$span->setAttribute( 'typeof', 'mw:Transclusion' );
$span->setAttribute( 'data-mw', json_encode( [ 'parts' => [ $wt ] ] ) );
return $span;
}
}