Tratar con los errores XML cuando se cargan documentos es una tarea muy sencilla. Utilizando la funcionalidad de libxml es posible suprimir todos los errores XML cuando se carga un documento para luego recorrerlos.
El objeto libXMLError, retornado por libxml_get_errors(), contiene varias propiedades, incluyendo el mensaje, línea y columna (posición) del error.
Ejemplo #1 Cargar un string XML erróneo
<?php
libxml_use_internal_errors(true);
$sxe = simplexml_load_string("<?xml version='1.0'><roto><xml></roto>");
if ($sxe === false) {
echo "Error cargando XML\n";
foreach(libxml_get_errors() as $error) {
echo "\t", $error->message;
}
}
?>El resultado del ejemplo sería:
Error cargando XML
Blank needed here
parsing XML declaration: '?>' expected
Opening and ending tag mismatch: xml line 1 and broken
Premature end of data in tag broken line 1
Note that "if (! $sxe) {" may give you a false-negative if the XML document was empty (e.g. "<root />"). In that case, $sxe will be:
object(SimpleXMLElement)#1 (0) {
}
which will evaluate to false, even though nothing technically went wrong.
Consider instead: "if ($sxe === false) {"If you need to process the content of your broken XML-doc you might find this interesting. It has blown past a few simple corruptions for me.
http://php.net/manual/en/class.domdocument.php#domdocument.props.recoverNow that the /e modifier is considered deprecated in preg_replace, you can use a negative lookahead to replace unescaped ampersands with & without throwing warnings:
$str = preg_replace('/&(?!;{6})/', '&', $str);
You probably should have been doing this before /e was deprecated, actually.