mirror of
https://gerrit.wikimedia.org/r/mediawiki/extensions/DiscussionTools
synced 2024-11-12 01:16:19 +00:00
763ce88021
For consistency with other DOM implementations. Change-Id: I20447d880ccd3b70b6694b36ea2f63dd0c42fa84
146 lines
3.1 KiB
PHP
146 lines
3.1 KiB
PHP
<?php
|
||
|
||
namespace MediaWiki\Extension\DiscussionTools;
|
||
|
||
use DOMNode;
|
||
use Exception;
|
||
use Throwable;
|
||
|
||
/**
|
||
* Partial implementation of W3 DOM4 TreeWalker interface.
|
||
*
|
||
* See also:
|
||
* - https://dom.spec.whatwg.org/#interface-treewalker
|
||
*
|
||
* Ported from https://github.com/TRowbotham/PHPDOM (MIT)
|
||
*/
|
||
class TreeWalker {
|
||
|
||
public $root;
|
||
public $whatToShow;
|
||
public $currentNode;
|
||
public $filter;
|
||
|
||
private $isActive = false;
|
||
|
||
/**
|
||
* See https://dom.spec.whatwg.org/#interface-treewalker
|
||
*
|
||
* @param DOMNode $root
|
||
* @param int $whatToShow
|
||
* @param callable|null $filter
|
||
*/
|
||
public function __construct(
|
||
DOMNode $root,
|
||
int $whatToShow = NodeFilter::SHOW_ALL,
|
||
callable $filter = null
|
||
) {
|
||
$this->currentNode = $root;
|
||
$this->filter = $filter;
|
||
$this->root = $root;
|
||
$this->whatToShow = $whatToShow;
|
||
}
|
||
|
||
/**
|
||
* See https://dom.spec.whatwg.org/#dom-treewalker-nextnode
|
||
*
|
||
* @return DOMNode|null The current node
|
||
*/
|
||
public function nextNode() : ?DOMNode {
|
||
$node = $this->currentNode;
|
||
$result = NodeFilter::FILTER_ACCEPT;
|
||
|
||
while ( true ) {
|
||
while ( $result !== NodeFilter::FILTER_REJECT && $node->firstChild !== null ) {
|
||
$node = $node->firstChild;
|
||
$result = $this->filterNode( $node );
|
||
if ( $result === NodeFilter::FILTER_ACCEPT ) {
|
||
$this->currentNode = $node;
|
||
return $node;
|
||
}
|
||
}
|
||
|
||
$sibling = null;
|
||
$temp = $node;
|
||
while ( $temp !== null ) {
|
||
if ( $temp === $this->root ) {
|
||
return null;
|
||
}
|
||
|
||
$sibling = $temp->nextSibling;
|
||
|
||
if ( $sibling !== null ) {
|
||
$node = $sibling;
|
||
|
||
break;
|
||
}
|
||
|
||
$temp = $temp->parentNode;
|
||
}
|
||
|
||
$result = $this->filterNode( $node );
|
||
|
||
if ( $result === NodeFilter::FILTER_ACCEPT ) {
|
||
$this->currentNode = $node;
|
||
|
||
return $node;
|
||
}
|
||
|
||
}
|
||
}
|
||
|
||
/**
|
||
* Filters a node.
|
||
*
|
||
* @internal
|
||
*
|
||
* @see https://dom.spec.whatwg.org/#concept-node-filter
|
||
*
|
||
* @param DOMNode $node The node to check.
|
||
* @return int Returns one of NodeFilter's FILTER_* constants.
|
||
* - NodeFilter::FILTER_ACCEPT
|
||
* - NodeFilter::FILTER_REJECT
|
||
* - NodeFilter::FILTER_SKIP
|
||
* @throws Exception
|
||
*/
|
||
private function filterNode( DOMNode $node ): int {
|
||
if ( $this->isActive ) {
|
||
throw new Exception( 'InvalidStateError' );
|
||
}
|
||
|
||
// Let n be node’s nodeType attribute value minus 1.
|
||
$n = $node->nodeType - 1;
|
||
|
||
// If the nth bit (where 0 is the least significant bit) of whatToShow
|
||
// is not set, return FILTER_SKIP.
|
||
if ( !( ( 1 << $n ) & $this->whatToShow ) ) {
|
||
return NodeFilter::FILTER_SKIP;
|
||
}
|
||
|
||
// If filter is null, return FILTER_ACCEPT.
|
||
if ( !$this->filter ) {
|
||
return NodeFilter::FILTER_ACCEPT;
|
||
}
|
||
|
||
$this->isActive = true;
|
||
|
||
try {
|
||
// Let $result be the return value of call a user object's operation
|
||
// with traverser's filter, "acceptNode", and Node. If this throws
|
||
// an exception, then unset traverser's active flag and rethrow the
|
||
// exception.
|
||
$result = $this->filter instanceof NodeFilter
|
||
? $this->filter->acceptNode( $node )
|
||
: ( $this->filter )( $node );
|
||
} catch ( Throwable $e ) {
|
||
$this->isActive = false;
|
||
|
||
throw $e;
|
||
}
|
||
|
||
$this->isActive = false;
|
||
|
||
return $result;
|
||
}
|
||
}
|