registerXPathNamespace example

    /** * Extract messages and metadata from DOMDocument into a MessageCatalogue. */
    private function extractXliff1(\DOMDocument $dom, MessageCatalogue $catalogue, string $domain): void
    {
        $xml = simplexml_import_dom($dom);
        $encoding = $dom->encoding ? strtoupper($dom->encoding) : null;

        $namespace = 'urn:oasis:names:tc:xliff:document:1.2';
        $xml->registerXPathNamespace('xliff', $namespace);

        foreach ($xml->xpath('//xliff:file') as $file) {
            $fileAttributes = $file->attributes();

            $file->registerXPathNamespace('xliff', $namespace);

            foreach ($file->xpath('.//xliff:prop') as $prop) {
                $catalogue->setCatalogueMetadata($prop->attributes()['prop-type'], (string) $prop, $domain);
            }

            foreach ($file->xpath('.//xliff:trans-unit') as $translation) {