PHP XML Validation Throws Fatal Exceptions When Passed Bad XML - php

Question

I've a quick function to load up an XML string, and validate it against a schema. When its given well formed XML, it behaves perfectly.
However when I muck up the xml syntax itself, php throws a fatal error and kills the script. I am checking the loadXML function return value, and I want a simple true/false. If the xml is dirty, loadXML() will fail and I can simply return validation failure. I've tried setting an empty error handler, but it still kills the script.
Any ideas? Do I need to downgrade errors or something?
Included code for reference (PHP):
function __maskerrors(){};
function ValidateImageXML($xml_string)
{
/* Parse XML data string into DOM object */
$xdoc = new DomDocument;
/* Calculate schema location */
$schema = dirname(realpath(__FILE__));
$schema.= "/image-xml-schema.xsd";
/* Mask any errors */
set_error_handler('__maskerrors');
/* Parse xml string, check for success */
if($xdoc->loadXML($xml_string))
{
/* Validate xml against schema */
if($xdoc->schemaValidate($schema))
{
/* Valid XML structure & valid against schema, return true */
return true;
}
else
{
/* Valid XML structure, but invalid against schema. Return false */
return false;
}
}
else
{
/* Invalid XML structure, return false */
return false;
}
/* Stop masking errors */
restore_error_handler();
}

Answer 1

Try with
libxml_use_internal_errors(true);
$xdoc->loadXml($yourXml);
libxml_clear_errors();
return $xdoc->schemaValidate($schema)
This will disable libxml errors and allow user to fetch error information as needed (or clear them)
See http://.php.net/manual/en/book.libxml.php