/**
* Extracts the pattern for the national format.
*
* @throws RuntimeException if multiple or no formats have been encountered.
* @return the national format string.
*/
private static function loadNationalFormat(PhoneMetadata $metadata, \DOMElement $numberFormatElement, NumberFormat $format)
{
self::setLeadingDigitsPatterns($numberFormatElement, $format);
$format->setPattern($numberFormatElement->getAttribute(self::PATTERN));
$formatPattern = $numberFormatElement->getElementsByTagName(self::FORMAT);
if ($formatPattern->length != 1) {
throw new \RuntimeException("Invalid number of format patterns for country: " . $metadata->getId());
}
$nationalFormat = $formatPattern->item(0)->firstChild->nodeValue;
$format->setFormat($nationalFormat);
return $nationalFormat;
}
