Querying and loading entities

In this recipe, we will use an entity query to find all published articles and return them as JSON. We will also allow specifying the sort order via a query parameter.

How to do it…

1. Create an index method in the ArticleController controller in your module that will receive the incoming Request object:

   <?php

   namespace Drupal\mymodule\Controller;

   use Drupal\Core\Controller\ControllerBase;

   use Symfony\Component\HttpFoundation\JsonResponse;

   use Symfony\Component\HttpFoundation\Request;

   class ArticleController extends ControllerBase {

     public function index(Request $request):

      JsonResponse {

     }

   }

The request object will be used to retrieve query parameters passed in the URL.

2. From the request, get the sort query parameter, defaulting to DESC:

     public function index(Request $request):

       JsonResponse {

      $sort = $request->query->get('sort&apos...