class RestResourceGetRouteProcessorBC

class RestResourceGetRouteProcessorBC implements OutboundRouteProcessorInterface {
    
    /**
     * The available serialization formats.
     *
     * @var string[]
     */
    protected $serializerFormats = [];
    
    /**
     * The route provider.
     *
     * @var \Drupal\Core\Routing\RouteProviderInterface
     */
    protected $routeProvider;
    
    /**
     * Constructs a RestResourceGetRouteProcessorBC object.
     *
     * @param string[] $serializer_formats
     *   The available serialization formats.
     * @param \Drupal\Core\Routing\RouteProviderInterface $route_provider
     *   The route provider.
     */
    public function __construct(array $serializer_formats, RouteProviderInterface $route_provider) {
        $this->serializerFormats = $serializer_formats;
        $this->routeProvider = $route_provider;
    }
    
    /**
     * {@inheritdoc}
     */
    public function processOutbound($route_name, Route $route, array &$parameters, BubbleableMetadata $bubbleable_metadata = NULL) {
        $route_name_parts = explode('.', $route_name);
        // BC: the REST module originally created per-format GET routes, instead
        // of a single route. To minimize the surface of this BC layer, this uses
        // route definitions that are as empty as possible, plus an outbound route
        // processor.
        // @see \Drupal\rest\Plugin\ResourceBase::routes()
        if ($route_name_parts[0] === 'rest' && $route_name_parts[count($route_name_parts) - 2] === 'GET' && in_array($route_name_parts[count($route_name_parts) - 1], $this->serializerFormats, TRUE)) {
            array_pop($route_name_parts);
            $redirected_route_name = implode('.', $route_name_parts);
            @trigger_error(sprintf("The '%s' route is deprecated since version 8.5.x and will be removed in 9.0.0. Use the '%s' route instead.", $route_name, $redirected_route_name), E_USER_DEPRECATED);
            static::overwriteRoute($route, $this->routeProvider
                ->getRouteByName($redirected_route_name));
        }
    }
    
    /**
     * Overwrites one route's metadata with the other's.
     *
     * @param \Symfony\Component\Routing\Route $target_route
     *   The route whose metadata to overwrite.
     * @param \Symfony\Component\Routing\Route $source_route
     *   The route whose metadata to read from.
     *
     * @see \Symfony\Component\Routing\Route
     */
    protected static function overwriteRoute(Route $target_route, Route $source_route) {
        $target_route->setPath($source_route->getPath());
        $target_route->setDefaults($source_route->getDefaults());
        $target_route->setRequirements($source_route->getRequirements());
        $target_route->setOptions($source_route->getOptions());
        $target_route->setHost($source_route->getHost());
        $target_route->setSchemes($source_route->getSchemes());
        $target_route->setMethods($source_route->getMethods());
    }

}