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|
<?php /*
+----------------------------------------------------------------------+
| Copyright (c) 1997-2025 The PHP Group |
+----------------------------------------------------------------------+
| This source file is subject to version 3.01 of the PHP license, |
| that is bundled with this package in the file LICENSE, and is |
| available through the world-wide-web at the following url: |
| https://www.php.net/license/3_01.txt. |
| If you did not receive a copy of the PHP license and are unable to |
| obtain it through the world-wide-web, please send a note to |
| license@php.net, so we can mail you a copy immediately. |
+----------------------------------------------------------------------+
| Authors: André L F S Bacci <ae php.net> |
+----------------------------------------------------------------------+
# Description
Loads XML fragments bodies[1] in DOM, while tolerating and not dropping
undefined entities references.
[1] https://www.w3.org/TR/xml-fragment/#d1e1332 */
class XmlFrag
{
static function listNodes( DOMNode $node , int $type )
{
$ret = [];
XmlFrag::listNodesRecurse( $node , $type , $ret );
return $ret;
}
static function listNodesRecurse( DOMNode $node , int $type, array & $ret )
{
if ( $node->nodeType == $type )
$ret[] = $node;
foreach( $node->childNodes as $child )
XmlFrag::listNodesRecurse( $child , $type, $ret );
}
static function loadXmlFragmentFile( string $filename , bool $fakeDtdForMissingEntity = true )
{
$contents = file_get_contents( $filename );
[ $doc , $ent , $err ] = XmlFrag::loadXmlFragmentText( $contents , "" );
if ( count( $err ) == 0 || $fakeDtdForMissingEntity == false )
return [ $doc , $ent , $err ];
$dtd = "<?xml version='1.0' encoding='utf-8'?>\n<!DOCTYPE frag [\n";
foreach ( $ent as $e )
$dtd .= "<!ENTITY $e ''>\n";
$dtd .= "]>\n";
[ $doc , $ign , $err ] = XmlFrag::loadXmlFragmentText( $contents , $dtd );
return [ $doc , $ent , $err ];
}
static function loadXmlFragmentText( string $contents , string $dtd )
{
if ( str_starts_with( ltrim( $contents ) , '<?xml' ) )
{
$pos1 = strpos( $contents , '<?xml' );
$pos2 = strpos( $contents , '?>' , $pos1 );
$contents = substr( $contents , $pos2 +2 );
}
$contents = $dtd . "<frag>" . $contents . "</frag>";
$doc = new DOMDocument();
$doc->recover = true;
$doc->resolveExternals = false;
$doc->substituteEntities = false;
$was = libxml_use_internal_errors( true );
$doc->loadXML( $contents );
$errors = libxml_get_errors();
libxml_clear_errors();
libxml_use_internal_errors( $was );
static $prefix = "", $suffix = "", $extra = "";
if ( $prefix == "" )
XmlFrag::setupErrors( $prefix , $suffix , $extra );
$ent = [];
$err = [];
foreach( $errors as $error )
{
$message = trim( $error->message );
if ( str_starts_with( $message , $prefix ) && str_ends_with( $message , $suffix ) )
{
$entity = $message;
$entity = str_replace( $prefix , "" , $entity );
$entity = str_replace( $suffix , "" , $entity );
$ent[] = $entity;
}
$err[] = $message;
}
$fragment = $doc->createDocumentFragment();
foreach( $doc->documentElement->childNodes as $node )
$fragment->append( $node->cloneNode( true ) );
$doc->removeChild( $doc->documentElement );
$doc->appendChild( $fragment );
return [ $doc , $ent , $err ];
}
static function setupErrors( string & $prefix , string & $suffix , string & $extra )
{
/*
Undefined entities references generate TWO different error messages on
some versions of libxml:
- "Entity '?' not defined" (for entity inside elements)
- "Extra content at the end of the document" (entity outside elements)
*/
$inside = "<x>&ZZZ;</x>";
$outside = "<x/>&ZZZ;";
$doc = new DOMDocument();
$doc->recover = true;
$doc->resolveExternals = false;
$doc->substituteEntities = false;
$was = libxml_use_internal_errors( true );
// prefix, suffix
$doc->loadXML( $inside );
$message = trim( libxml_get_errors()[0]->message );
[ $prefix , $suffix ] = explode( "ZZZ" , $message );
libxml_clear_errors();
// extra
$doc->loadXML( $outside );
$extra = trim( libxml_get_errors()[0]->message );
libxml_clear_errors();
if ( strpos( $extra, "ZZZ" ) !== false )
throw new Exception( "Unexpected error message." );
libxml_use_internal_errors( $was );
}
}
|
