How to add a default controller to the <front> route?

Question

Is it possible to add a default controller to the '<front>' route? There's no default controller defined in system.routing.yml.

I'm trying to get a handle on it by using the following code:

<?php

namespace Drupal\mymodule\Routing;

use Drupal\Core\Routing\RouteSubscriberBase;
use Symfony\Component\Routing\RouteCollection;

/**
 * Listens to the dynamic route events.
 */
class RouteSubscriber extends RouteSubscriberBase {

  /**
   * {@inheritdoc}
   */
  protected function alterRoutes(RouteCollection $collection) {
    // Get front page and set controller.
    if ($route = $collection->get('<front>')) {
      $route->setDefault('_controller', '\Drupal\mymodule\Controller\MyModuleController::MyModuleMethod');
    }
  }

}

But it doesn't seem to do anything. However this code works when replacing '<front>' with another route like help.main. Why is that? Do I have to add the controller instead of setting it? (D8)

Answer 1

<front> is not really a route that can be resolved for an incoming request, it's just a helper for building a URL.

It works in the opposite way, you create a controller at whatever path you want, and then you set the frontpage to that path on the system information page aka in the system.site configuration object.