3. Create child admins

Let us say you have a PlaylistAdmin and a VideoAdmin. You can optionally declare the VideoAdmin to be a child of the PlaylistAdmin. This will create new routes like, for example, /playlist/{id}/video/list, where the videos will automatically be filtered by post.

To do this, you first need to call the addChild method in your PlaylistAdmin service configuration with two arguments, the child admin name (in this case VideoAdmin service) and the Entity field that relates our child Entity with its parent:

# config/services.yaml

App\Admin\VideoAdmin:
    # tags, calls, etc

App\Admin\PlaylistAdmin:
    calls:
        - [addChild, ['@App\Admin\VideoAdmin', 'playlist']]
        # Or `[addChild, ['@App\Admin\VideoAdmin']]` if there is no
        # field to access the Playlist from the Video entity

To display the VideoAdmin extend the menu in your PlaylistAdmin class:

namespace App\Admin;

use Knp\Menu\ItemInterface as MenuItemInterface;
use Sonata\AdminBundle\Admin\AbstractAdmin;
use Sonata\AdminBundle\Admin\AdminInterface;

final class PlaylistAdmin extends AbstractAdmin
{
    protected function configureTabMenu(MenuItemInterface $menu, string $action, ?AdminInterface $childAdmin = null): void
    {
        if (!$childAdmin && !in_array($action, ['edit', 'show'])) {
            return;
        }

        $admin = $this->isChild() ? $this->getParent() : $this;
        $id = $admin->getRequest()->get('id');

        $menu->addChild('View Playlist', $admin->generateMenuUrl('show', ['id' => $id]));

        if ($this->isGranted('EDIT')) {
            $menu->addChild('Edit Playlist', $admin->generateMenuUrl('edit', ['id' => $id]));
        }

        if ($this->isGranted('LIST')) {
            $menu->addChild('Manage Videos', $admin->generateMenuUrl('App\Admin\VideoAdmin.list', ['id' => $id]));
        }
    }
}

It also possible to set a dot-separated value, like post.author, if your parent and child admins are not directly related.

Be wary that being a child admin is optional, which means that regular routes will be created regardless of whether you actually need them or not. To get rid of them, you may override the configureRoutes method:

namespace App\Admin;

use Sonata\AdminBundle\Admin\AbstractAdmin;
use Sonata\AdminBundle\Route\RouteCollectionInterface;

final class VideoAdmin extends AbstractAdmin
{
    protected function configureRoutes(RouteCollectionInterface $collection): void
    {
        if ($this->isChild()) {
            return;
        }

        // This is the route configuration as a parent
        $collection->clear();

    }
}

You can nest admins as deep as you wish.

Let’s say you want to add comments to videos.

You can then add your CommentAdmin admin service as a child of the VideoAdmin admin service.

Finally, the admin interface will look like this: