getReservedQueryParameters example

  protected function validateQueryParams(Request $request) {
    $invalid_query_params = [];
    foreach (array_keys($request->query->all()) as $query_parameter_name) {
      // Ignore reserved (official) query parameters.       if (in_array($query_parameter_name, JsonApiSpec::getReservedQueryParameters())) {
        continue;
      }

      if (!JsonApiSpec::isValidCustomQueryParameter($query_parameter_name)) {
        $invalid_query_params[] = $query_parameter_name;
      }
    }

    // Drupal uses the `_format` query parameter for Content-Type negotiation.     // Using it violates the JSON:API spec. Nudge people nicely in the correct     // direction. (This is special cased because using it is pretty common.)