ImageStyleRoutes.php

<?php

namespace Drupal\image\Routing;

use Drupal\Core\DependencyInjection\ContainerInjectionInterface;
use Drupal\Core\StreamWrapper\StreamWrapperManagerInterface;
use Symfony\Component\DependencyInjection\ContainerInterface;
use Symfony\Component\Routing\Route;

/**
 * Defines a route subscriber to register a URL for serving image styles.
 */
class ImageStyleRoutes implements ContainerInjectionInterface {
    
    /**
     * The stream wrapper manager service.
     *
     * @var \Drupal\Core\StreamWrapper\StreamWrapperManagerInterface
     */
    protected $streamWrapperManager;
    
    /**
     * Constructs a new ImageStyleRoutes object.
     *
     * @param \Drupal\Core\StreamWrapper\StreamWrapperManagerInterface $stream_wrapper_manager
     *   The stream wrapper manager service.
     */
    public function __construct(StreamWrapperManagerInterface $stream_wrapper_manager) {
        $this->streamWrapperManager = $stream_wrapper_manager;
    }
    
    /**
     * {@inheritdoc}
     */
    public static function create(ContainerInterface $container) {
        return new static($container->get('stream_wrapper_manager'));
    }
    
    /**
     * Returns an array of route objects.
     *
     * @return \Symfony\Component\Routing\Route[]
     *   An array of route objects.
     */
    public function routes() {
        $routes = [];
        // Generate image derivatives of publicly available files. If clean URLs are
        // disabled image derivatives will always be served through the menu system.
        // If clean URLs are enabled and the image derivative already exists, PHP
        // will be bypassed.
        $directory_path = $this->streamWrapperManager
            ->getViaScheme('public')
            ->getDirectoryPath();
        $routes['image.style_public'] = new Route('/' . $directory_path . '/styles/{image_style}/{scheme}', [
            '_controller' => 'Drupal\\image\\Controller\\ImageStyleDownloadController::deliver',
            'required_derivative_scheme' => 'public',
        ], [
            '_access' => 'TRUE',
        ]);
        return $routes;
    }

}