/**
* Validate the document against a schema.
*
* @param string $filename An optional filename of a given schema the document should validate against.
* @throws \qtism\data\storage\xml\XmlStorageException
* @throws \InvalidArgumentException
*/
public function schemaValidate($filename = '')
{
if (empty($filename)) {
$filename = XmlUtils::getSchemaLocation($this->getVersion());
}
if (is_readable($filename)) {
$oldErrorConfig = libxml_use_internal_errors(true);
$doc = $this->getDomDocument();
if (@$doc->schemaValidate($filename) === false) {
$libXmlErrors = libxml_get_errors();
$formattedErrors = self::formatLibXmlErrors($libXmlErrors);
libxml_clear_errors();
libxml_use_internal_errors($oldErrorConfig);
$msg = "The document could not be validated with XML Schema:\n{$formattedErrors}";
throw new XmlStorageException($msg, XmlStorageException::XSD_VALIDATION, null, new LibXmlErrorCollection($libXmlErrors));
}
} else {
$msg = "Schema '{$filename}' cannot be read. Does this file exist? Is it readable?";
throw new InvalidArgumentException($msg);
}
}
