php__symfony__book/src/Controller/BlogController.php

<?php

namespace App\Controller;

use Symfony\Bundle\FrameworkBundle\Controller\Controller;
use Symfony\Component\HttpFoundation\Response;
use Symfony\Component\Routing\Annotation\Route;
use Symfony\Component\Routing\Generator\UrlGeneratorInterface;

class BlogController extends Controller {

  /**
   * @param $page
   *
   * @return Response
   *
   * @Route(
   *   name ="blog_list",
   *   path ="/blog/{page}",
   *   requirements={"page" = "\d+"}
   * )
   */
  public function list($page = 1) {
    return new Response("Page $page of the blog list.");
  }

  /**
   * @param $slug
   *
   * @return \Symfony\Component\HttpFoundation\Response
   *
   * @Route(
   *   name = "blog_show",
   *   path = "/blog/{slug}"
   * )
   */
  public function show($slug) {
    $path = $this->generateUrl('blog_list', [
      // Placeholder: fit in the path.
      'page' => 2,
      // Non-placeholder: fit in the query
      'foo' => 'bar',
    ], UrlGeneratorInterface::ABSOLUTE_PATH);
    return new Response("Show $slug. Back to page 2: $path");
  }

}