Neos\Flow\Mvc\Routing\DynamicRoutePart::findValueToMatch PHP Method

    protected function findValueToMatch($routePath)
    {
        if (!isset($routePath) || $routePath === '' || $routePath[0] === '/') {
            return '';
        }
        $valueToMatch = $routePath;
        if ($this->splitString !== '') {
            $splitStringPosition = strpos($valueToMatch, $this->splitString);
            if ($splitStringPosition !== false) {
                $valueToMatch = substr($valueToMatch, 0, $splitStringPosition);
            }
        }
        if (strpos($valueToMatch, '/') !== false) {
            return '';
        }
        return $valueToMatch;
    }

 /**
  * Returns the first part of $routePath that should be evaluated in matchValue().
  * If no split string is set (route part is the last in the routes uriPattern), the complete $routePart is returned.
  * Otherwise the part is returned that matches the specified uriPattern of this route part.
  *
  * @param string $routePath The request path to be matched
  * @return string value to match, or an empty string if $routePath is empty, split string was not found or uriPattern could not be matched
  * @api
  */
 protected function findValueToMatch($routePath)
 {
     if (!isset($routePath) || $routePath === '' || $routePath[0] === '/') {
         return '';
     }
     if ($this->getUriPattern() === '') {
         return parent::findValueToMatch($routePath);
     }
     $regexPattern = preg_quote($this->getUriPattern(), '/');
     $regexPattern = preg_replace('/\\\\{[^}]+\\\\}/', '[^\\/]+', $regexPattern);
     if ($this->splitString !== '') {
         $regexPattern .= '(?=' . preg_quote($this->splitString, '/') . ')';
     }
     $matches = [];
     preg_match('/^' . $regexPattern . '/', trim($routePath, '/'), $matches);
     return isset($matches[0]) ? $matches[0] : '';
 }